Merge the month seating copies, resize state and page grids (#418)

Step 8 of the simplification review: the three behaviour-sensitive merges. Each lands behind a characterization test written and passed against the old code first.

**Month row seating**
- `MonthWeek.seating(col, laneCap)` is the one source for which event sits in which lane and what overflows. `laneEvents`, `chipAt`, `overflowEvents` and MonthWeekRow's inline copy all build on it, so dots, bars and pills can't drift apart (#53).
- MonthWeekRow computes the seating once per row (`remember(week, laneCap)`) instead of re-filtering every column on each recomposition.
- `OverflowDots.total` and `shownLanes` are gone; they always equalled `events.size` and `laneCap`.
- MonthSeatingTest pins the four old copies against each other over 400 generated weeks × lane caps 0–6; they agreed everywhere, and `seating()` matches them.

**Timeline resize**
- TimelineDragController's eight loose `resize*` fields are one `ResizeSession?`, so cancel clears it in one assignment. Moves mutate it in place; no per-frame allocation. None of the fields were Compose state.
- Only difference: a resize starting without the previous one ending used to inherit the old held slot; it now starts clean.

**Timeline paging**
- Week, multi-day and day page through one `DaysGrid` with `weeks(firstDay)`, `days` and `startingAt(date, count)` factories; the PageGrid interface, WeekGrid and DayGrid are gone. Page numbers and grid equality (used by pager keys) are unchanged; PageNumberingTest pins them.
- jumpToDate no longer detects the multi-day view by class; it re-frames when the target would open mid-page, which a test checks against the old rule for every in-range date.

Not yet checked on a device. Worth a look: month bars/pills/+N dots on crowded days in paged and split styles plus the split morph, chip taps and month drag; resize of both edges incl. across midnight, cancel then plain drag, RTL; paging, view switching, jump to date/today, week-start and multi-day count changes.

Co-authored-by: Jean-Luc Makiola <business@jeanlucmakiola.de>
Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/418

app/build.gradle.kts

@@ -175,7 +175,10 @@ dependencies {
     implementation("de.jeanlucmakiola.floret:core-time")
     implementation("de.jeanlucmakiola.floret:core-locale")
     implementation("de.jeanlucmakiola.floret:core-crash")
+    implementation("de.jeanlucmakiola.floret:core-di")
+    implementation("de.jeanlucmakiola.floret:core-prefs")
     implementation("de.jeanlucmakiola.floret:core-reminders")
+    implementation("de.jeanlucmakiola.floret:core-android")
     implementation("de.jeanlucmakiola.floret:identity")
     implementation("de.jeanlucmakiola.floret:components")
     implementation(libs.kotlinx.coroutines.core)

app/src/androidTest/java/de/jeanlucmakiola/calendula/data/calendar/MoveEventExceptionsTest.kt

@@ -0,0 +1,91 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import android.Manifest
+import android.content.ContentUris
+import android.content.ContentValues
+import android.provider.CalendarContract
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.rule.GrantPermissionRule
+import com.google.common.truth.Truth.assertThat
+import de.jeanlucmakiola.calendula.domain.toEditForm
+import kotlinx.datetime.TimeZone
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * Moving a synced series keeps its deleted and edited occurrences, although the
+ * moved row has no `_sync_id` for exception rows to attach to.
+ */
+@RunWith(AndroidJUnit4::class)
+class MoveEventExceptionsTest {
+
+    @get:Rule
+    val permissionRule: GrantPermissionRule = GrantPermissionRule.grant(
+        Manifest.permission.READ_CALENDAR,
+        Manifest.permission.WRITE_CALENDAR,
+    )
+
+    private val context = InstrumentationRegistry.getInstrumentation().targetContext
+    private val resolver = context.contentResolver
+    private val ds = AndroidCalendarDataSource(context)
+    private val zone = TimeZone.currentSystemDefault()
+
+    private val day = 86_400_000L
+    private val start = 1_893_492_000_000L // 2030-01-01T10:00Z
+    private val hour = 3_600_000L
+
+    /** "day offset:title" of every instance on [calendarId]. */
+    private fun occurrences(calendarId: Long): List<String> =
+        ds.instances(start - day, start + 10 * day)
+            .filter { it.calendarId == calendarId }
+            .map { "${(it.start.toEpochMilliseconds() - start) / day}:${it.title}" }
+            .sorted()
+
+    @Test
+    fun movedSeriesKeepsCancelledAndModifiedOccurrences() {
+        val a = ds.createLocalCalendar("move-test-a", 0xFF336699.toInt(), null)
+        val b = ds.createLocalCalendar("move-test-b", 0xFF993366.toInt(), null)
+        try {
+            val src = insertSyncedSeries(a)
+            ds.deleteOccurrence(src, start + 2 * day)
+            val occurrence = ds.eventDetail(src, 540)!!.toEditForm(start + 3 * day, start + 3 * day + hour, zone)
+            ds.updateOccurrence(src, start + 3 * day, occurrence, occurrence.copy(title = "edited"), 540)
+            val expected = listOf("0:series", "1:series", "3:edited", "4:series")
+            assertThat(occurrences(a)).isEqualTo(expected)
+
+            val form = ds.eventDetail(src, 540)!!.toEditForm(start, start + hour, zone)
+            ds.moveEvent(src, b, form, form, 540)
+
+            assertThat(occurrences(a)).isEmpty()
+            assertThat(occurrences(b)).isEqualTo(expected)
+        } finally {
+            ds.deleteCalendar(a)
+            ds.deleteCalendar(b)
+        }
+    }
+
+    /** A daily series carrying a `_sync_id`, so its exceptions are real exception rows. */
+    private fun insertSyncedSeries(calendarId: Long): Long {
+        val accountName = resolver.query(
+            ContentUris.withAppendedId(CalendarContract.Calendars.CONTENT_URI, calendarId),
+            arrayOf(CalendarContract.Calendars.ACCOUNT_NAME), null, null, null,
+        )!!.use { it.moveToFirst(); it.getString(0) }
+        val uri = CalendarContract.Events.CONTENT_URI.buildUpon()
+            .appendQueryParameter(CalendarContract.CALLER_IS_SYNCADAPTER, "true")
+            .appendQueryParameter(CalendarContract.Calendars.ACCOUNT_NAME, accountName)
+            .appendQueryParameter(CalendarContract.Calendars.ACCOUNT_TYPE, CalendarContract.ACCOUNT_TYPE_LOCAL)
+            .build()
+        val values = ContentValues().apply {
+            put(CalendarContract.Events.CALENDAR_ID, calendarId)
+            put(CalendarContract.Events.TITLE, "series")
+            put(CalendarContract.Events.DTSTART, start)
+            put(CalendarContract.Events.DURATION, "P3600S")
+            put(CalendarContract.Events.RRULE, "FREQ=DAILY;COUNT=5")
+            put(CalendarContract.Events.EVENT_TIMEZONE, "UTC")
+            put(CalendarContract.Events._SYNC_ID, "move-test-series")
+        }
+        return ContentUris.parseId(resolver.insert(uri, values)!!)
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/MainActivity.kt

@@ -29,11 +29,15 @@ import androidx.lifecycle.lifecycleScope
 import dagger.hilt.android.AndroidEntryPoint
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
-import de.jeanlucmakiola.calendula.data.prefs.ThemeMode
+import de.jeanlucmakiola.floret.prefs.ThemeMode
+import de.jeanlucmakiola.floret.prefs.isDark
+import de.jeanlucmakiola.floret.prefs.isPureBlack
 import de.jeanlucmakiola.calendula.data.prefs.is24Hour
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.buildInsertEventForm
 import de.jeanlucmakiola.calendula.domain.sharedTextOrNull
+import de.jeanlucmakiola.calendula.ui.ExternalRequests
+import de.jeanlucmakiola.calendula.ui.InsertRequest
 import de.jeanlucmakiola.calendula.ui.RootScreen
 import de.jeanlucmakiola.calendula.ui.common.LocalShowHourGrid
 import de.jeanlucmakiola.calendula.ui.common.LocalMultiDayCount
@@ -65,9 +69,6 @@ import kotlin.time.Clock
 import kotlin.time.Instant
 import javax.inject.Inject
 
-/** A prefilled create form from an external launch, with the source it came from. */
-private data class InsertRequest(val form: EventForm, val source: ImportSource)
-
 @AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
 
@@ -79,23 +80,12 @@ class MainActivity : AppCompatActivity() {
     // picks up the in-app override instead of the night resource qualifier.
     private var systemBarsDark = false
 
-    // The occurrence a reminder notification was tapped for (eventId, begin,
-    // end — the detail screen's key shape). singleTop + onNewIntent route a
-    // tap into the running activity; CalendarHost consumes and clears it.
-    private var requestedDetailKey by mutableStateOf<LongArray?>(null)
-
-    // A navigation a home-screen widget asked for (open a date / start a
-    // create). Consumed once by CalendarHost, same pattern as the detail key.
-    private var requestedNav by mutableStateOf<WidgetNavRequest?>(null)
-
-    // An .ics file opened/shared into the app (ACTION_VIEW/SEND). Consumed once
-    // by CalendarHost's import flow.
-    private var requestedImportUri by mutableStateOf<Uri?>(null)
-
-    // A prefilled new-event form from an external ACTION_INSERT launch (another
-    // app/widget asking us to create an event, issue #30) or shared text (#306).
-    // Consumed once by CalendarHost, which opens it in the create form for review.
-    private var requestedInsert by mutableStateOf<InsertRequest?>(null)
+    private val requests = ExternalRequests(
+        onExternalFormClosed = {
+            insertFormOpen = false
+            if (launchedForInsert) finish()
+        },
+    )
 
     // Whether such a form is still open. Only then does a recreation re-read the
     // intent to bring it back; a saved or dismissed one stays closed.
@@ -105,11 +95,6 @@ class MainActivity : AppCompatActivity() {
     // app that asked instead of leaving the calendar on top of it.
     private var launchedForInsert = false
 
-    // An external "edit this event" (ACTION_EDIT on content://.../events/<id>):
-    // opens the occurrence in the edit form. Same occurrence-key shape as the
-    // detail channel; consumed once by CalendarHost.
-    private var requestedEditKey by mutableStateOf<LongArray?>(null)
-
     // A captured crash report awaiting the user's decision, surfaced as a dialog
     // over the calendar on the next launch (the single-crash path). A startup
     // crash-loop is handled out of band, before setContent — see below.
@@ -137,11 +122,7 @@ class MainActivity : AppCompatActivity() {
         // backdrop and bar icons instead of the night qualifier's (#181).
         val cachedTheme = WindowThemeCache.read(this)
         cachedTheme?.windowBackgroundRes()?.let { window.setBackgroundDrawableResource(it) }
-        systemBarsDark = when (cachedTheme) {
-            null, ThemeMode.SYSTEM -> systemDark
-            ThemeMode.LIGHT -> false
-            ThemeMode.DARK, ThemeMode.BLACK -> true
-        }
+        systemBarsDark = (cachedTheme ?: ThemeMode.SYSTEM).isDark(systemDark)
         applyEdgeToEdge()
         lifecycleScope.launch {
             settingsPrefs.themeMode.collect { mode ->
@@ -163,28 +144,24 @@ class MainActivity : AppCompatActivity() {
         // it's still open.
         val replaying = savedInstanceState != null || intent.isRelaunch()
         if (!replaying) {
-            requestedDetailKey = intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull()
-            requestedEditKey = intent.editEventKeyOrNull()
+            requests.detailKey = intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull()
+            requests.editKey = intent.editEventKeyOrNull()
         }
-        requestedNav = intent.navRequestOrNull()
+        requests.nav = intent.navRequestOrNull()
             ?.takeUnless { replaying && it is WidgetNavRequest.OpenEvent }
-        requestedImportUri = intent.importUriOrNull()
+        requests.importUri = intent.importUriOrNull()
         val insertOpenBefore = savedInstanceState?.getBoolean(KEY_INSERT_FORM_OPEN) == true
-        requestedInsert = intent.createRequestOrNull()?.takeIf { !replaying || insertOpenBefore }
-        insertFormOpen = requestedInsert != null
+        requests.insert = intent.createRequestOrNull()?.takeIf { !replaying || insertOpenBefore }
+        insertFormOpen = requests.insert != null
         launchedForInsert = savedInstanceState?.getBoolean(KEY_LAUNCHED_FOR_INSERT)
-            ?: (requestedInsert != null)
+            ?: (requests.insert != null)
         if (CrashReporter.shouldPrompt(this)) pendingCrashReport = CrashReporter.pendingReport(this)
         setContent {
             // One activity-scoped SettingsViewModel drives both the theme here
             // and the Settings screen, so a theme change applies app-wide at once.
             val settingsViewModel: SettingsViewModel = hiltViewModel()
             val settings by settingsViewModel.state.collectAsStateWithLifecycle()
-            val darkTheme = when (settings.themeMode) {
-                ThemeMode.SYSTEM -> isSystemInDarkTheme()
-                ThemeMode.LIGHT -> false
-                ThemeMode.DARK, ThemeMode.BLACK -> true
-            }
+            val darkTheme = settings.themeMode.isDark(isSystemInDarkTheme())
             // onCreate can only see the night resource qualifier, not the in-app
             // override — re-apply from the resolved theme so the bar icons follow
             // the app's light/dark choice.
@@ -223,7 +200,7 @@ class MainActivity : AppCompatActivity() {
             CalendulaTheme(
                 darkTheme = darkTheme,
                 dynamicColor = settings.dynamicColor,
-                pureBlack = settings.themeMode == ThemeMode.BLACK,
+                pureBlack = settings.themeMode.isPureBlack,
                 typography = typography,
             ) {
                 Box(modifier = Modifier.fillMaxSize()) {
@@ -236,21 +213,7 @@ class MainActivity : AppCompatActivity() {
                     ) {
                         RootScreen(
                             modifier = Modifier.fillMaxSize(),
-                            requestedDetailKey = requestedDetailKey,
-                            onDetailKeyConsumed = { requestedDetailKey = null },
-                            widgetNavRequest = requestedNav,
-                            onWidgetNavConsumed = { requestedNav = null },
-                            requestedImportUri = requestedImportUri,
-                            onImportConsumed = { requestedImportUri = null },
-                            requestedInsertForm = requestedInsert?.form,
-                            requestedInsertSource = requestedInsert?.source ?: ImportSource.Insert,
-                            onInsertConsumed = { requestedInsert = null },
-                            onExternalFormClosed = {
-                                insertFormOpen = false
-                                if (launchedForInsert) finish()
-                            },
-                            requestedEditKey = requestedEditKey,
-                            onEditKeyConsumed = { requestedEditKey = null },
+                            requests = requests,
                         )
                     }
                     // A persistent corner marker so a debug build is never
@@ -310,14 +273,14 @@ class MainActivity : AppCompatActivity() {
 
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
-        (intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull())?.let { requestedDetailKey = it }
-        intent.navRequestOrNull()?.let { requestedNav = it }
-        intent.importUriOrNull()?.let { requestedImportUri = it }
+        (intent.detailKeyOrNull() ?: intent.viewEventKeyOrNull())?.let { requests.detailKey = it }
+        intent.navRequestOrNull()?.let { requests.nav = it }
+        intent.importUriOrNull()?.let { requests.importUri = it }
         intent.createRequestOrNull()?.let {
-            requestedInsert = it
+            requests.insert = it
             insertFormOpen = true
         }
-        intent.editEventKeyOrNull()?.let { requestedEditKey = it }
+        intent.editEventKeyOrNull()?.let { requests.editKey = it }
     }
 
     /**

app/src/main/java/de/jeanlucmakiola/calendula/data/backup/AutoBackup.kt

@@ -5,12 +5,10 @@ import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
 import android.content.Context
-import android.content.pm.PackageManager
 import android.os.Build
 import android.util.Log
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
-import androidx.core.content.ContextCompat
 import androidx.core.net.toUri
 import androidx.work.CoroutineWorker
 import androidx.work.ExistingPeriodicWorkPolicy
@@ -28,6 +26,7 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
+import de.jeanlucmakiola.floret.android.hasPermission
 import kotlinx.coroutines.flow.first
 import java.util.concurrent.TimeUnit
 import kotlin.time.Clock
@@ -133,8 +132,7 @@ class BackupWorker(
 
     private fun notifyFailure(context: Context) {
         val canPost = Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU ||
-            ContextCompat.checkSelfPermission(context, Manifest.permission.POST_NOTIFICATIONS) ==
-            PackageManager.PERMISSION_GRANTED
+            context.hasPermission(Manifest.permission.POST_NOTIFICATIONS)
         if (!canPost) return
         val manager = NotificationManagerCompat.from(context)
         manager.createNotificationChannel(

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarDataSource.kt

@@ -1,13 +1,12 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
-import de.jeanlucmakiola.floret.time.toEpochMillis
+import de.jeanlucmakiola.floret.android.hasPermission
 import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import android.Manifest
 import android.content.ContentResolver
 import android.content.ContentUris
 import android.content.ContentValues
 import android.content.Context
-import android.content.pm.PackageManager
 import android.database.ContentObserver
 import android.database.Cursor
 import android.net.Uri
@@ -15,7 +14,6 @@ import android.os.Handler
 import android.os.Looper
 import android.provider.CalendarContract
 import android.util.Log
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.domain.Attendee
 import de.jeanlucmakiola.calendula.domain.AttendeeRelationship
@@ -28,7 +26,6 @@ import de.jeanlucmakiola.calendula.domain.curatedForPicker
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.EventSearch
-import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.Reminder
 import de.jeanlucmakiola.calendula.domain.SearchCandidate
 import de.jeanlucmakiola.calendula.domain.contacts.MANAGED_UID_PREFIX
@@ -36,9 +33,11 @@ import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.semanticReminderMinutes
+import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
 import de.jeanlucmakiola.calendula.domain.rruleTruncatedAt
+import de.jeanlucmakiola.calendula.domain.toEditForm
+import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toJavaLocalDate
-import java.time.Instant
 import java.time.LocalDate
 import java.time.ZoneId
 import java.time.ZoneOffset
@@ -76,21 +75,13 @@ interface CalendarDataSource {
 
     /**
      * The event-colour palette the calendar's account publishes
-     * (`CalendarContract.Colors`, `TYPE_EVENT`), curated for display — deduped,
-     * thinned to visually distinct swatches when oversized (CalDAV adapters
-     * publish all ~147 CSS3 names, #22) and hue-sorted; see [curatedForPicker].
+     * (`CalendarContract.Colors`, `TYPE_EVENT`), every key in provider order.
      * Empty when the account exposes no palette (most local calendars, some
      * CalDAV) — the signal that a custom colour can only be written as a raw
-     * `EVENT_COLOR`, which a synced calendar may drop on its next sync.
-     */
-    fun eventColorPalette(calendarId: Long): List<EventColorOption>
-
-    /**
-     * The same palette **uncurated** — every key the account publishes, in
-     * provider order. Curation is a display concession (it folds look-alikes and
-     * drops the neutrals outright from an oversized palette), so matching a
-     * colour that came from outside the account has to run against the full set:
-     * those keys are all the calendar accepts. See [eventColorPalette].
+     * `EVENT_COLOR`, which a synced calendar may drop on its next sync. The
+     * picker shows it curated ([curatedForPicker]); matching a colour that came
+     * from outside the account runs against this full set, since those keys are
+     * all the calendar accepts.
      */
     fun publishedEventColors(calendarId: Long): List<EventColorOption>
 
@@ -238,8 +229,10 @@ interface CalendarDataSource {
      * and cancelled occurrences) to [targetCalendarId], returning the new
      * `Events._ID`. `CALENDAR_ID` is sync-adapter-owned and can't be updated in
      * place, so this is copy+delete: the row is re-inserted on the target (its
-     * `UID_2445` preserved), its exceptions, reminders and editable guests
-     * replayed, the [original]→[updated] field edits applied, then the source
+     * `UID_2445` preserved), its reminders and editable guests copied, its
+     * exceptions turned into EXDATEs (modified ones also into standalone events,
+     * as the new row has no `_sync_id` to attach them to), the
+     * [original]→[updated] field edits applied, then the source
      * deleted. The source is removed only once the copy fully succeeds; a failure
      * before that rolls the new event back, leaving the original untouched.
      * [allDayReminderTimeMinutes]: see [insertEvent].
@@ -323,8 +316,7 @@ class AndroidCalendarDataSource @Inject constructor(
     private val registeredObservers = mutableSetOf<ContentObserver>()
 
     private fun hasCalendarPermission(): Boolean =
-        ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CALENDAR) ==
-            PackageManager.PERMISSION_GRANTED
+        context.hasPermission(Manifest.permission.READ_CALENDAR)
 
     /**
      * Attach any not-yet-registered observers to the provider, but only once the
@@ -358,7 +350,7 @@ class AndroidCalendarDataSource @Inject constructor(
             CalendarProjection.COLUMNS,
             null, null,
             CalendarContract.Calendars.CALENDAR_DISPLAY_NAME + " ASC",
-        )?.use { it.mapAll(::toCalendarSource) } ?: emptyList()
+        )?.use { c -> c.mapRows { toCalendarSource() } } ?: emptyList()
     }
 
     /**
@@ -375,7 +367,20 @@ class AndroidCalendarDataSource @Inject constructor(
         )
         .build()
 
-    override fun createLocalCalendar(displayName: String, color: Int, description: String?): Long {
+    override fun createLocalCalendar(displayName: String, color: Int, description: String?): Long =
+        insertLocalCalendar(displayName, color, "create local calendar") { putDescription(description) }
+
+    /**
+     * Insert an owned, visible, syncing calendar on the Calendula local account;
+     * [extra] adds the columns that tell the kinds apart. [what] names the write
+     * in the failure — never the calendar name, which can reach a crash report.
+     */
+    private fun insertLocalCalendar(
+        displayName: String,
+        color: Int,
+        what: String,
+        extra: ContentValues.() -> Unit,
+    ): Long {
         val name = displayName.trim()
         val values = ContentValues().apply {
             put(CalendarContract.Calendars.ACCOUNT_NAME, LOCAL_ACCOUNT_NAME)
@@ -391,11 +396,9 @@ class AndroidCalendarDataSource @Inject constructor(
             )
             put(CalendarContract.Calendars.VISIBLE, 1)
             put(CalendarContract.Calendars.SYNC_EVENTS, 1)
-            putDescription(description)
+            extra()
         }
-        val uri = resolver.insert(localCalendarsUri(), values)
-            // No calendar name in the message — it can reach a crash report.
-            ?: throw WriteFailedException("create local calendar")
+        val uri = resolver.insert(localCalendarsUri(), values) ?: throw WriteFailedException(what)
         return ContentUris.parseId(uri)
     }
 
@@ -460,33 +463,15 @@ class AndroidCalendarDataSource @Inject constructor(
     }
 
     override fun canWriteCalendars(): Boolean =
-        ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_CALENDAR) ==
-            PackageManager.PERMISSION_GRANTED
+        context.hasPermission(Manifest.permission.WRITE_CALENDAR)
 
-    override fun createManagedCalendar(displayName: String, color: Int, type: SpecialDateType): Long {
-        val name = displayName.trim()
-        val values = ContentValues().apply {
-            put(CalendarContract.Calendars.ACCOUNT_NAME, LOCAL_ACCOUNT_NAME)
-            put(CalendarContract.Calendars.ACCOUNT_TYPE, CalendarContract.ACCOUNT_TYPE_LOCAL)
-            put(CalendarContract.Calendars.OWNER_ACCOUNT, LOCAL_ACCOUNT_NAME)
-            put(CalendarContract.Calendars.NAME, name)
-            put(CalendarContract.Calendars.CALENDAR_DISPLAY_NAME, name)
-            put(CalendarContract.Calendars.CALENDAR_COLOR, color)
-            put(
-                CalendarContract.Calendars.CALENDAR_ACCESS_LEVEL,
-                CalendarContract.Calendars.CAL_ACCESS_OWNER,
-            )
-            put(CalendarContract.Calendars.VISIBLE, 1)
-            put(CalendarContract.Calendars.SYNC_EVENTS, 1)
+    override fun createManagedCalendar(displayName: String, color: Int, type: SpecialDateType): Long =
+        insertLocalCalendar(displayName, color, "create managed calendar") {
             // The marker that identifies this as our special-dates calendar,
             // independent of the (user-editable) display name. CAL_SYNC1 already
             // holds the description, so the marker lives in CAL_SYNC2.
             put(MANAGED_MARKER_COLUMN, markerFor(type))
         }
-        val uri = resolver.insert(localCalendarsUri(), values)
-            ?: throw WriteFailedException("create managed calendar")
-        return ContentUris.parseId(uri)
-    }
 
     override fun findManagedCalendars(): List<ManagedCalendarRow> = resolver.query(
         CalendarContract.Calendars.CONTENT_URI,
@@ -550,22 +535,16 @@ class AndroidCalendarDataSource @Inject constructor(
         // Seeded once, then never re-touched by sync — so a user who moves a
         // birthday reminder keeps their change. Encoded against the upcoming
         // occurrence, not the ancient DTSTART anchor (wrong timezone offset).
-        val anchor = Instant.ofEpochMilli(times.dtStartMillis).atZone(ZoneOffset.UTC).toLocalDate()
         insertReminderRows(
             eventId,
-            managedAllDayReminderMinutes(anchor, form.reminders, allDayReminderTimeMinutes),
+            managedAllDayReminderMinutes(utcDate(times.dtStartMillis), form.reminders, allDayReminderTimeMinutes),
         )
         return eventId
     }
 
     override fun updateManagedFields(eventId: Long, values: Map<String, Any?>) {
         if (values.isEmpty()) return
-        val rows = resolver.update(
-            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
-            values.toContentValues(),
-            null, null,
-        )
-        if (rows == 0) throw WriteFailedException("update managed event id=$eventId")
+        updateEventRow(eventId, values.toContentValues(), "update managed event id=$eventId")
     }
 
     override fun applyManagedCalendarReminders(
@@ -573,38 +552,21 @@ class AndroidCalendarDataSource @Inject constructor(
         allDayReminderTimeMinutes: Int,
         minutes: List<Int>,
     ) {
-        resolver.query(
-            CalendarContract.Events.CONTENT_URI,
-            arrayOf(CalendarContract.Events._ID, CalendarContract.Events.DTSTART),
-            // Only our own mirror events, so a stray user event in this calendar
-            // isn't all-day-re-encoded or stripped of its own reminders.
-            "${CalendarContract.Events.CALENDAR_ID} = ? AND " +
-                "${CalendarContract.Events.DELETED} = 0 AND " +
-                "${CalendarContract.Events.UID_2445} LIKE ?",
-            arrayOf(calendarId.toString(), "$MANAGED_UID_PREFIX%"),
-            null,
-        )?.use { c ->
-            while (c.moveToNext()) {
-                val eventId = c.getLong(0)
-                // Managed events are all-day: DTSTART is a UTC midnight anchor.
-                val anchor = Instant.ofEpochMilli(c.getLong(1))
-                    .atZone(ZoneOffset.UTC).toLocalDate()
-                reconcileReminders(
-                    eventId,
-                    managedAllDayReminderMinutes(anchor, minutes, allDayReminderTimeMinutes),
-                )
-            }
+        // Only our own mirror events, so a stray user event in this calendar
+        // isn't all-day-re-encoded or stripped of its own reminders.
+        queryManagedEvents(calendarId).forEach { event ->
+            // Managed events are all-day: DTSTART is a UTC midnight anchor.
+            reconcileReminders(
+                event.eventId,
+                managedAllDayReminderMinutes(utcDate(event.dtStartMillis), minutes, allDayReminderTimeMinutes),
+            )
         }
     }
 
     override fun instances(beginMillis: Long, endMillis: Long): List<EventInstance> {
         ensureObserversRegistered()
-        val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
-            ContentUris.appendId(this, beginMillis)
-            ContentUris.appendId(this, endMillis)
-        }.build()
         return resolver.query(
-            uri,
+            instancesUri(beginMillis, endMillis),
             InstanceProjection.COLUMNS,
             // Hide cancelled occurrences: "delete only this event" writes a
             // cancelled exception for the one instance (#47). A NULL status is a
@@ -617,7 +579,7 @@ class AndroidCalendarDataSource @Inject constructor(
                 "${CalendarContract.Events.DELETED} = 0",
             null,
             CalendarContract.Instances.BEGIN + " ASC",
-        )?.use { c -> c.mapAllNotNull { CursorColumnReader(c).toEventInstance() } } ?: emptyList()
+        )?.use { c -> c.mapRowsNotNull { toEventInstance() } } ?: emptyList()
     }
 
     override fun searchEvents(query: String): List<SearchCandidate> {
@@ -721,13 +683,9 @@ class AndroidCalendarDataSource @Inject constructor(
         endMillis: Long,
         soonestFirst: Boolean,
     ): Pair<Long, Long>? {
-        val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
-            ContentUris.appendId(this, beginMillis)
-            ContentUris.appendId(this, endMillis)
-        }.build()
         val order = CalendarContract.Instances.BEGIN + if (soonestFirst) " ASC" else " DESC"
         return resolver.query(
-            uri,
+            instancesUri(beginMillis, endMillis),
             arrayOf(CalendarContract.Instances.BEGIN, CalendarContract.Instances.END),
             "${CalendarContract.Instances.EVENT_ID} = ?",
             arrayOf(eventId.toString()),
@@ -741,7 +699,7 @@ class AndroidCalendarDataSource @Inject constructor(
         val attendees = queryAttendees(eventId)
         val reminders = queryReminders(eventId)
         return resolver.query(
-            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+            eventUri(eventId),
             EventDetailProjection.COLUMNS,
             null, null, null,
         )?.use { c ->
@@ -752,9 +710,6 @@ class AndroidCalendarDataSource @Inject constructor(
         }
     }
 
-    override fun eventColorPalette(calendarId: Long): List<EventColorOption> =
-        publishedEventColors(calendarId).curatedForPicker()
-
     override fun publishedEventColors(calendarId: Long): List<EventColorOption> {
         val account = calendarAccount(calendarId) ?: return emptyList()
         return resolver.query(
@@ -807,11 +762,10 @@ class AndroidCalendarDataSource @Inject constructor(
             null,
             CalendarContract.Events.DTSTART + " ASC",
         )?.use { c ->
-            c.mapAll {
-                val reader = CursorColumnReader(c)
-                val eventId = reader.getLong(EventExportProjection.IDX_ID)
-                val calendarId = reader.getLong(EventExportProjection.IDX_CALENDAR_ID)
-                reader.toIcsEvent(
+            c.mapRows {
+                val eventId = getLong(EventExportProjection.IDX_ID)
+                val calendarId = getLong(EventExportProjection.IDX_CALENDAR_ID)
+                toIcsEvent(
                     reminderMinutes = queryReminders(eventId).map { it.minutes },
                     calendarName = names[calendarId],
                     allDayReminderTimeMinutes = allDayReminderTimeMinutes,
@@ -846,7 +800,7 @@ class AndroidCalendarDataSource @Inject constructor(
             calendarId = calendarId,
             // Preserve the file's UID so a re-import dedups against it; mint one
             // only when the source event carried none.
-            uid = event.uid?.takeIf { it.isNotBlank() } ?: "${UUID.randomUUID()}@calendula",
+            uid = event.uid?.takeIf { it.isNotBlank() } ?: mintUid(),
             palette = colorPalette,
         )
         val uri = resolver.insert(CalendarContract.Events.CONTENT_URI, values.toContentValues())
@@ -859,8 +813,7 @@ class AndroidCalendarDataSource @Inject constructor(
         // (see [importedAllDayReminderDate]).
         val reminderDate = if (event.isAllDay) {
             importedAllDayReminderDate(
-                startDate = Instant.ofEpochMilli(event.start.toEpochMilliseconds())
-                    .atZone(ZoneOffset.UTC).toLocalDate(),
+                startDate = utcDate(event.start.toEpochMilliseconds()),
                 recurrenceRule = event.recurrenceRule,
                 today = LocalDate.now(zone),
             )
@@ -878,24 +831,7 @@ class AndroidCalendarDataSource @Inject constructor(
             } else {
                 minutes
             }
-            val reminder = ContentValues().apply {
-                put(CalendarContract.Reminders.EVENT_ID, eventId)
-                put(CalendarContract.Reminders.MINUTES, providerMinutes)
-                put(CalendarContract.Reminders.METHOD, CalendarContract.Reminders.METHOD_ALERT)
-            }
-            // The event row is already in. A reminder that won't attach costs
-            // that one alarm, not the event: throwing here would have the import
-            // count an event it did create as failed, and the retry would then
-            // skip it as a duplicate.
-            val attached = try {
-                resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder)
-            } catch (e: Exception) {
-                Log.w(TAG, "Reminder insert threw for imported event $eventId", e)
-                null
-            }
-            if (attached == null) {
-                Log.w(TAG, "Failed to attach reminder ($minutes min) to imported event $eventId")
-            }
+            insertReminderRow(eventId, providerMinutes)
         }
         return eventId
     }
@@ -951,18 +887,13 @@ class AndroidCalendarDataSource @Inject constructor(
         // back to a stable synthesised UID at export time (deriveIcsUid).
         val values = buildEventInsertValues(
             form,
-            uid = "${UUID.randomUUID()}@calendula",
+            uid = mintUid(),
             times = form.toWriteTimes(ZoneId.systemDefault()),
-        ).toContentValues().apply {
-            // A null colour just leaves both columns unset (the event inherits
-            // its calendar's colour), so only the key/raw cases are written.
-            when {
-                form.colorKey != null ->
-                    put(CalendarContract.Events.EVENT_COLOR_KEY, form.colorKey)
-                form.color != null -> put(CalendarContract.Events.EVENT_COLOR, form.color)
-            }
-        }
-        val uri = resolver.insert(CalendarContract.Events.CONTENT_URI, values)
+        ) + eventColorColumns(form.colorKey, form.color)
+            // A new row has nothing to clear: unset columns inherit the
+            // calendar's colour, so only the key/raw values are written.
+            .filterValues { it != null }
+        val uri = resolver.insert(CalendarContract.Events.CONTENT_URI, values.toContentValues())
             ?: throw WriteFailedException("insert event into calendar id=${form.calendarId}")
         val eventId = ContentUris.parseId(uri)
         seedReminders(eventId, form, allDayReminderTimeMinutes)
@@ -983,16 +914,32 @@ class AndroidCalendarDataSource @Inject constructor(
 
     /** Insert one `METHOD_ALERT` reminder row per raw provider offset. */
     private fun insertReminderRows(eventId: Long, encodedMinutes: List<Int>) {
-        encodedMinutes.forEach { minutes ->
-            val reminder = ContentValues().apply {
-                put(CalendarContract.Reminders.EVENT_ID, eventId)
-                put(CalendarContract.Reminders.MINUTES, minutes)
-                put(CalendarContract.Reminders.METHOD, CalendarContract.Reminders.METHOD_ALERT)
-            }
-            if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder) == null) {
-                Log.w(TAG, "Failed to attach reminder ($minutes min) to event $eventId")
-            }
+        encodedMinutes.forEach { insertReminderRow(eventId, it) }
+    }
+
+    /**
+     * Best effort: the event row is already in, so a reminder that won't attach
+     * costs that one alarm, not the event. Throwing would report an event that
+     * was created as failed — and an import retry would then skip it as a
+     * duplicate.
+     */
+    private fun insertReminderRow(
+        eventId: Long,
+        minutes: Int,
+        method: Int = CalendarContract.Reminders.METHOD_ALERT,
+    ) {
+        val reminder = ContentValues().apply {
+            put(CalendarContract.Reminders.EVENT_ID, eventId)
+            put(CalendarContract.Reminders.MINUTES, minutes)
+            put(CalendarContract.Reminders.METHOD, method)
         }
+        val attached = try {
+            resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder)
+        } catch (e: Exception) {
+            Log.w(TAG, "Reminder insert threw for event $eventId", e)
+            null
+        }
+        if (attached == null) Log.w(TAG, "Failed to attach reminder ($minutes min) to event $eventId")
     }
 
     /**
@@ -1029,12 +976,7 @@ class AndroidCalendarDataSource @Inject constructor(
             zone = ZoneId.systemDefault(),
         )
         if (values.isNotEmpty()) {
-            val rows = resolver.update(
-                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
-                values.toContentValues(),
-                null, null,
-            )
-            if (rows == 0) throw WriteFailedException("update event id=$eventId")
+            updateEventRow(eventId, values.toContentValues(), "update event id=$eventId")
         }
         // Untouched reminder sets are left alone so unrelated edits can't
         // disturb provider rows the form never knew about. The diff is on the
@@ -1067,16 +1009,17 @@ class AndroidCalendarDataSource @Inject constructor(
             ?: throw WriteFailedException("read event to move id=$eventId")
         // Keep the source UID so an .ics backup dedups and a sync adapter can
         // recognise the moved event; mint one only if the source carried none.
-        val uid = master.uid?.takeIf { it.isNotEmpty() } ?: "${UUID.randomUUID()}@calendula"
+        val uid = master.uid?.takeIf { it.isNotEmpty() } ?: mintUid()
         val newEventId = resolver.insert(
             CalendarContract.Events.CONTENT_URI,
             buildMovedMasterValues(master.event, targetCalendarId, uid).toContentValues(),
         )?.let(ContentUris::parseId)
             ?: throw WriteFailedException("insert moved event into calendar id=$targetCalendarId")
+        val detached = mutableListOf<Long>()
         try {
             copyReminderRows(fromEventId = eventId, toEventId = newEventId)
             insertAttendees(newEventId, editableAttendees(eventId))
-            copyExceptions(fromEventId = eventId, toEventId = newEventId)
+            copyExceptions(eventId, newEventId, targetCalendarId, allDayReminderTimeMinutes, detached)
             // Apply the user's field edits exactly as a same-calendar "all
             // events" save would: the moved master carries the source's values,
             // so the dirty diff against [original] writes only what changed
@@ -1086,6 +1029,7 @@ class AndroidCalendarDataSource @Inject constructor(
             // Undo the partial copy so a failed move leaves nothing behind; the
             // source is still intact (it's deleted only past this point).
             runCatching { deleteEvent(newEventId) }
+            detached.forEach(::rollBackDetached)
             throw t
         }
         deleteEvent(eventId)
@@ -1094,7 +1038,7 @@ class AndroidCalendarDataSource @Inject constructor(
 
     /** The master row of the event to move, as a verbatim-insert snapshot. */
     private fun queryMoveMaster(eventId: Long): MoveMaster? = resolver.query(
-        ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+        eventUri(eventId),
         MoveMasterProjection.COLUMNS,
         null, null, null,
     )?.use { c ->
@@ -1106,8 +1050,7 @@ class AndroidCalendarDataSource @Inject constructor(
                 title = r.getString(MoveMasterProjection.IDX_TITLE).orEmpty(),
                 isAllDay = r.getInt(MoveMasterProjection.IDX_ALL_DAY) != 0,
                 dtStartMillis = r.getLong(MoveMasterProjection.IDX_DTSTART),
-                dtEndMillis = r.getLong(MoveMasterProjection.IDX_DTEND)
-                    .takeUnless { r.isNull(MoveMasterProjection.IDX_DTEND) },
+                dtEndMillis = r.getLongOrNull(MoveMasterProjection.IDX_DTEND),
                 duration = r.getString(MoveMasterProjection.IDX_DURATION),
                 rrule = r.getString(MoveMasterProjection.IDX_RRULE)?.takeIf { it.isNotBlank() },
                 rdate = r.getString(MoveMasterProjection.IDX_RDATE),
@@ -1115,8 +1058,7 @@ class AndroidCalendarDataSource @Inject constructor(
                 timezone = r.getString(MoveMasterProjection.IDX_EVENT_TIMEZONE),
                 availability = r.getInt(MoveMasterProjection.IDX_AVAILABILITY),
                 accessLevel = r.getInt(MoveMasterProjection.IDX_ACCESS_LEVEL),
-                status = r.getInt(MoveMasterProjection.IDX_STATUS)
-                    .takeUnless { r.isNull(MoveMasterProjection.IDX_STATUS) },
+                status = r.getIntOrNull(MoveMasterProjection.IDX_STATUS),
                 location = r.getString(MoveMasterProjection.IDX_LOCATION),
                 description = r.getString(MoveMasterProjection.IDX_DESCRIPTION),
             ),
@@ -1133,16 +1075,7 @@ class AndroidCalendarDataSource @Inject constructor(
         arrayOf(fromEventId.toString()),
         null,
     )?.use { c ->
-        while (c.moveToNext()) {
-            val values = ContentValues().apply {
-                put(CalendarContract.Reminders.EVENT_ID, toEventId)
-                put(CalendarContract.Reminders.MINUTES, c.getInt(0))
-                put(CalendarContract.Reminders.METHOD, c.getInt(1))
-            }
-            if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, values) == null) {
-                Log.w(TAG, "Failed to copy a reminder to moved event $toEventId")
-            }
-        }
+        while (c.moveToNext()) insertReminderRow(toEventId, minutes = c.getInt(0), method = c.getInt(1))
     } ?: Unit
 
     /**
@@ -1162,44 +1095,33 @@ class AndroidCalendarDataSource @Inject constructor(
         }
 
     /**
-     * Replay every exception of the series [fromEventId] against the moved series
-     * [toEventId]. The copy preserved the recurrence skeleton, so each occurrence
-     * time still resolves: a cancelled occurrence is re-hidden with a cancelled
-     * exception, a modified one is re-inserted with its fields (then its reminders
-     * reconciled and editable guests copied). No-op for a non-recurring event.
+     * Carry every exception of the series [fromEventId] over to the moved series
+     * [toEventId]. The moved row has no `_sync_id` yet, so exception rows would
+     * never attach to it ([deleteOccurrence], [detachOccurrence]): a cancelled
+     * occurrence becomes an EXDATE, a modified one an EXDATE plus a standalone
+     * event on [targetCalendarId], its id added to [detached] for rollback.
      */
-    private fun copyExceptions(fromEventId: Long, toEventId: Long) {
-        queryExceptionRows(fromEventId).forEach { ex ->
-            if (ex.isCancelled) {
-                val values = ContentValues().apply {
-                    put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, ex.originalInstanceMillis)
-                    put(CalendarContract.Events.STATUS, CalendarContract.Events.STATUS_CANCELED)
-                }
-                resolver.insert(
-                    ContentUris.withAppendedId(
-                        CalendarContract.Events.CONTENT_EXCEPTION_URI, toEventId,
-                    ),
-                    values,
-                ) ?: throw WriteFailedException("copy cancelled occurrence to event id=$toEventId")
-            } else {
-                val uri = resolver.insert(
-                    ContentUris.withAppendedId(
-                        CalendarContract.Events.CONTENT_EXCEPTION_URI, toEventId,
-                    ),
-                    buildCopiedExceptionValues(ex).toContentValues(),
-                ) ?: throw WriteFailedException("copy modified occurrence to event id=$toEventId")
-                val newExceptionId = ContentUris.parseId(uri)
-                // The provider may clone the parent's reminders onto the new
-                // exception; reconcile to the source exception's exact set so
-                // they neither double nor drop. Same DTSTART → same all-day
-                // encoding, so the stored offsets match directly.
-                reconcileReminders(
-                    newExceptionId,
-                    queryReminders(ex.exceptionEventId).map { it.minutes },
-                )
-                insertAttendees(newExceptionId, editableAttendees(ex.exceptionEventId))
-            }
+    private fun copyExceptions(
+        fromEventId: Long,
+        toEventId: Long,
+        targetCalendarId: Long,
+        allDayReminderTimeMinutes: Int,
+        detached: MutableList<Long>,
+    ) {
+        val exceptions = queryExceptionRows(fromEventId)
+        if (exceptions.isEmpty()) return
+        val zone = TimeZone.currentSystemDefault()
+        exceptions.filterNot { it.isCancelled }.forEach { ex ->
+            val detail = eventDetail(ex.exceptionEventId, allDayReminderTimeMinutes)
+                ?: throw WriteFailedException("read modified occurrence id=${ex.exceptionEventId}")
+            val endMillis = ex.dtEndMillis ?: (ex.dtStartMillis + parseRfc2445DurationMillis(ex.duration))
+            val form = detail.toEditForm(ex.dtStartMillis, endMillis, zone)
+                .copy(calendarId = targetCalendarId)
+                .toDetachedOccurrence()
+            detached += insertEvent(form, allDayReminderTimeMinutes)
         }
+        val values = querySeriesRow(toEventId).exdateValues(exceptions.map { it.originalInstanceMillis })
+        updateEventRow(toEventId, values, "exdate moved exceptions event id=$toEventId")
     }
 
     /** The series' exception rows (modified + cancelled), oldest occurrence first. */
@@ -1210,26 +1132,14 @@ class AndroidCalendarDataSource @Inject constructor(
         arrayOf(seriesEventId.toString()),
         CalendarContract.Events.ORIGINAL_INSTANCE_TIME + " ASC",
     )?.use { c ->
-        c.mapAll {
-            val r = CursorColumnReader(c)
-            val status = r.getInt(ExceptionProjection.IDX_STATUS)
-                .takeUnless { r.isNull(ExceptionProjection.IDX_STATUS) }
+        c.mapRows {
             ExceptionRowSnapshot(
-                exceptionEventId = r.getLong(ExceptionProjection.IDX_ID),
-                originalInstanceMillis = r.getLong(ExceptionProjection.IDX_ORIGINAL_INSTANCE_TIME),
-                isCancelled = status == CalendarContract.Events.STATUS_CANCELED,
-                status = status,
-                title = r.getString(ExceptionProjection.IDX_TITLE).orEmpty(),
-                isAllDay = r.getInt(ExceptionProjection.IDX_ALL_DAY) != 0,
-                dtStartMillis = r.getLong(ExceptionProjection.IDX_DTSTART),
-                dtEndMillis = r.getLong(ExceptionProjection.IDX_DTEND)
-                    .takeUnless { r.isNull(ExceptionProjection.IDX_DTEND) },
-                duration = r.getString(ExceptionProjection.IDX_DURATION),
-                timezone = r.getString(ExceptionProjection.IDX_EVENT_TIMEZONE),
-                availability = r.getInt(ExceptionProjection.IDX_AVAILABILITY),
-                accessLevel = r.getInt(ExceptionProjection.IDX_ACCESS_LEVEL),
-                location = r.getString(ExceptionProjection.IDX_LOCATION),
-                description = r.getString(ExceptionProjection.IDX_DESCRIPTION),
+                exceptionEventId = getLong(ExceptionProjection.IDX_ID),
+                originalInstanceMillis = getLong(ExceptionProjection.IDX_ORIGINAL_INSTANCE_TIME),
+                isCancelled = getIntOrNull(ExceptionProjection.IDX_STATUS) == CalendarContract.Events.STATUS_CANCELED,
+                dtStartMillis = getLong(ExceptionProjection.IDX_DTSTART),
+                dtEndMillis = getLongOrNull(ExceptionProjection.IDX_DTEND),
+                duration = getString(ExceptionProjection.IDX_DURATION),
             )
         }
     } ?: emptyList()
@@ -1266,7 +1176,7 @@ class AndroidCalendarDataSource @Inject constructor(
         val exceptionId = ContentUris.parseId(uri)
         form.colorKey?.let { key ->
             resolver.update(
-                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, exceptionId),
+                eventUri(exceptionId),
                 ContentValues().apply { put(CalendarContract.Events.EVENT_COLOR_KEY, key) },
                 null, null,
             )
@@ -1320,34 +1230,19 @@ class AndroidCalendarDataSource @Inject constructor(
         // a fresh UID — the detached row is a separate event now, and sharing the
         // parent's would collide with it in .ics restore dedup.
         val detachedId = insertEvent(form.toDetachedOccurrence(), allDayReminderTimeMinutes)
-        val values = buildOccurrenceExdateValues(
-            existingExdate = row.exdate,
-            occurrenceMillis = beginMillis,
-            dtStartMillis = row.dtStartMillis,
-            rrule = row.rrule,
-            rdate = row.rdate,
-            duration = row.duration,
-            timezone = row.timezone,
-            allDay = row.allDay,
-        )
         // Rows touched, not occurrences excluded — 1 whenever the series row still
         // exists. It catches the row disappearing under us, not an EXDATE the
         // provider's expansion fails to match.
-        val updatedRows = try {
-            resolver.update(
-                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
-                values.toContentValues(), null, null,
+        try {
+            updateEventRow(
+                eventId,
+                row.exdateValues(listOf(beginMillis)),
+                "exdate occurrence for edit, event id=$eventId begin=$beginMillis",
             )
         } catch (t: Throwable) {
             rollBackDetached(detachedId)
             throw t
         }
-        if (updatedRows == 0) {
-            rollBackDetached(detachedId)
-            throw WriteFailedException(
-                "exdate occurrence for edit, event id=$eventId begin=$beginMillis",
-            )
-        }
         return detachedId
     }
 
@@ -1420,23 +1315,11 @@ class AndroidCalendarDataSource @Inject constructor(
             updated = updated,
             zone = ZoneId.systemDefault(),
         ) ?: return
-        val row = querySeriesRow(newEventId)
-        val values = ContentValues().apply {
+        val values = querySeriesRow(newEventId).timeColumns().apply {
             put(CalendarContract.Events.EXDATE, carried)
-            put(CalendarContract.Events.DTSTART, row.dtStartMillis)
-            put(CalendarContract.Events.RRULE, row.rrule)
-            put(CalendarContract.Events.DURATION, row.duration)
-            put(CalendarContract.Events.EVENT_TIMEZONE, row.timezone)
-            put(CalendarContract.Events.ALL_DAY, row.allDay)
         }
         try {
-            val rows = resolver.update(
-                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, newEventId),
-                values, null, null,
-            )
-            if (rows == 0) {
-                throw WriteFailedException("carry exdate onto split series id=$newEventId")
-            }
+            updateEventRow(newEventId, values, "carry exdate onto split series id=$newEventId")
         } catch (t: Throwable) {
             runCatching { deleteEvent(newEventId) }
             throw t
@@ -1464,29 +1347,18 @@ class AndroidCalendarDataSource @Inject constructor(
      */
     private fun truncateSeries(eventId: Long, row: SeriesRow, beginMillis: Long) {
         requireNotNull(row.rrule) { "truncateSeries needs a recurring row" }
-        val values = ContentValues().apply {
-            put(CalendarContract.Events.DTSTART, row.dtStartMillis)
-            put(CalendarContract.Events.DURATION, row.duration)
-            put(CalendarContract.Events.EVENT_TIMEZONE, row.timezone)
-            put(CalendarContract.Events.ALL_DAY, row.allDay)
+        val values = row.timeColumns().apply {
             put(
                 CalendarContract.Events.RRULE,
                 rruleTruncatedAt(row.rrule, untilUtcMillis = row.truncationCutoff(beginMillis)),
             )
         }
-        val rows = resolver.update(
-            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
-            values,
-            null, null,
-        )
-        if (rows == 0) {
-            throw WriteFailedException("truncate series event id=$eventId begin=$beginMillis")
-        }
+        updateEventRow(eventId, values, "truncate series event id=$eventId begin=$beginMillis")
     }
 
     /** The series anchor: every time-related column of the Events row. */
     private fun querySeriesRow(eventId: Long): SeriesRow = resolver.query(
-        ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+        eventUri(eventId),
         arrayOf(
             CalendarContract.Events.DTSTART,
             CalendarContract.Events.RRULE,
@@ -1534,6 +1406,30 @@ class AndroidCalendarDataSource @Inject constructor(
          */
         val recurs: Boolean get() = !rrule.isNullOrBlank() || !rdate.isNullOrBlank()
 
+        /**
+         * The time/recurrence set a series write carries together: the provider
+         * re-expands instances only from what the update itself holds.
+         */
+        fun timeColumns(): ContentValues = ContentValues().apply {
+            put(CalendarContract.Events.DTSTART, dtStartMillis)
+            put(CalendarContract.Events.RRULE, rrule)
+            put(CalendarContract.Events.DURATION, duration)
+            put(CalendarContract.Events.EVENT_TIMEZONE, timezone)
+            put(CalendarContract.Events.ALL_DAY, allDay)
+        }
+
+        /** This row's columns with [occurrences] added to EXDATE ([buildOccurrencesExdateValues]). */
+        fun exdateValues(occurrences: List<Long>): Map<String, Any?> = buildOccurrencesExdateValues(
+            existingExdate = exdate,
+            occurrences = occurrences,
+            dtStartMillis = dtStartMillis,
+            rrule = rrule,
+            rdate = rdate,
+            duration = duration,
+            timezone = timezone,
+            allDay = allDay,
+        )
+
         /** UNTIL cutoff for ending the series before the occurrence at [beginMillis]. */
         fun truncationCutoff(beginMillis: Long): Long = previousLocalDayEndUtcMillis(
             beginMillis = beginMillis,
@@ -1559,20 +1455,10 @@ class AndroidCalendarDataSource @Inject constructor(
                 arrayOf(eventId.toString(), minutes.toString()),
             )
         }
-        (target - existing).forEach { minutes ->
-            val reminder = ContentValues().apply {
-                put(CalendarContract.Reminders.EVENT_ID, eventId)
-                put(CalendarContract.Reminders.MINUTES, minutes)
-                put(CalendarContract.Reminders.METHOD, CalendarContract.Reminders.METHOD_ALERT)
-            }
-            if (resolver.insert(CalendarContract.Reminders.CONTENT_URI, reminder) == null) {
-                Log.w(TAG, "Failed to attach reminder ($minutes min) to event $eventId")
-            }
-        }
+        insertReminderRows(eventId, (target - existing).toList())
     }
 
-    /** Normalised key an attendee is matched/deduped on (case-insensitive email). */
-    private fun EventAttendee.key(): String = email.trim().lowercase()
+    private fun EventAttendee.key(): String = emailKey(email)
 
     /** Distinct guests by email; blanks dropped (we key and write on the address). */
     private fun List<EventAttendee>.distinctByEmail(): List<EventAttendee> {
@@ -1624,7 +1510,7 @@ class AndroidCalendarDataSource @Inject constructor(
         val relationship: Int,
         val type: Int,
     ) {
-        val key: String get() = email.trim().lowercase()
+        val key: String get() = emailKey(email)
     }
 
     private fun queryAttendeeRows(eventId: Long): List<AttendeeRow> = resolver.query(
@@ -1689,17 +1575,20 @@ class AndroidCalendarDataSource @Inject constructor(
                 )
             }
         }
-        target.filterNot { it.key() in editableKeys }.forEach { attendee ->
-            if (resolver.insert(
-                    CalendarContract.Attendees.CONTENT_URI,
-                    attendeeValues(eventId, attendee),
-                ) == null
-            ) {
-                Log.w(TAG, "Failed to attach a guest to event $eventId")
-            }
-        }
+        insertAttendees(eventId, target.filterNot { it.key() in editableKeys })
     }
 
+    private fun eventUri(eventId: Long): Uri =
+        ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId)
+
+    /** Update the Events row [eventId]; [what] names the write when no row was touched. */
+    private fun updateEventRow(eventId: Long, values: ContentValues, what: String) {
+        if (resolver.update(eventUri(eventId), values, null, null) == 0) throw WriteFailedException(what)
+    }
+
+    private fun updateEventRow(eventId: Long, values: Map<String, Any?>, what: String) =
+        updateEventRow(eventId, values.toContentValues(), what)
+
     private fun Map<String, Any?>.toContentValues(): ContentValues =
         ContentValues().also { cv ->
             forEach { (column, value) ->
@@ -1716,7 +1605,7 @@ class AndroidCalendarDataSource @Inject constructor(
 
     override fun deleteEvent(eventId: Long) {
         val deleted = resolver.delete(
-            ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
+            eventUri(eventId),
             null, null,
         )
         if (deleted == 0) throw WriteFailedException("delete event id=$eventId")
@@ -1738,23 +1627,11 @@ class AndroidCalendarDataSource @Inject constructor(
             // occurrence with it (#47 on a local calendar). EXDATE needs no link.
             // Calendula's own contact special-date calendars are local and hold
             // yearly series, so this path is reached in normal use.
-            val values = buildOccurrenceExdateValues(
-                existingExdate = row.exdate,
-                occurrenceMillis = beginMillis,
-                dtStartMillis = row.dtStartMillis,
-                rrule = row.rrule,
-                rdate = row.rdate,
-                duration = row.duration,
-                timezone = row.timezone,
-                allDay = row.allDay,
+            updateEventRow(
+                eventId,
+                row.exdateValues(listOf(beginMillis)),
+                "exdate occurrence event id=$eventId begin=$beginMillis",
             )
-            val updated = resolver.update(
-                ContentUris.withAppendedId(CalendarContract.Events.CONTENT_URI, eventId),
-                values.toContentValues(), null, null,
-            )
-            if (updated == 0) {
-                throw WriteFailedException("exdate occurrence event id=$eventId begin=$beginMillis")
-            }
             return
         }
         // A cancelled exception row hides exactly this occurrence; the sync
@@ -1804,7 +1681,7 @@ class AndroidCalendarDataSource @Inject constructor(
         CalendarContract.Attendees.EVENT_ID + " = ?",
         arrayOf(eventId.toString()),
         null,
-    )?.use { c -> c.mapAll { CursorColumnReader(c).toAttendee() } } ?: emptyList()
+    )?.use { c -> c.mapRows { toAttendee() } } ?: emptyList()
 
     private fun queryReminders(eventId: Long): List<Reminder> = resolver.query(
         CalendarContract.Reminders.CONTENT_URI,
@@ -1812,19 +1689,15 @@ class AndroidCalendarDataSource @Inject constructor(
         CalendarContract.Reminders.EVENT_ID + " = ?",
         arrayOf(eventId.toString()),
         null,
-    )?.use { c -> c.mapAll { CursorColumnReader(c).toReminder() } } ?: emptyList()
-
-    private fun toCalendarSource(c: Cursor): CalendarSource = CursorColumnReader(c).toCalendarSource()
+    )?.use { c -> c.mapRows { toReminder() } } ?: emptyList()
 
     /** Iterate every row and map; skips nothing. */
     private inline fun <T> Cursor.mapAll(mapper: (Cursor) -> T): List<T> = buildList {
         while (moveToNext()) add(mapper(this@mapAll))
     }
 
-    /** Iterate every row and map; drops nulls. */
-    private inline fun <T : Any> Cursor.mapAllNotNull(mapper: (Cursor) -> T?): List<T> = buildList {
-        while (moveToNext()) mapper(this@mapAllNotNull)?.let(::add)
-    }
+    /** A fresh globally-unique `UID_2445`, for an event that carries none of its own. */
+    private fun mintUid(): String = "${UUID.randomUUID()}@calendula"
 
     /** The `CAL_SYNC2` marker value identifying a managed calendar's [type]. */
     private fun markerFor(type: SpecialDateType): String = when (type) {
@@ -1840,6 +1713,9 @@ class AndroidCalendarDataSource @Inject constructor(
     private companion object {
         const val TAG = "CalendarDataSource"
 
+        /** Normalised key an attendee is matched/deduped on (case-insensitive email). */
+        fun emailKey(email: String): String = email.trim().lowercase()
+
         /**
          * Shared account for every app-created local calendar, so they group
          * together (by account) in the filter sheet and calendar manager.

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepository.kt

@@ -29,7 +29,7 @@ interface CalendarRepository {
 
     /**
      * The event-colour palette a calendar's account publishes; empty when it
-     * exposes none (see [CalendarDataSource.eventColorPalette]).
+     * exposes none (see [CalendarDataSource.publishedEventColors]).
      */
     suspend fun eventColorPalette(calendarId: Long): List<EventColorOption>
 

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositoryImpl.kt

@@ -1,10 +1,11 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
 import android.util.Log
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import de.jeanlucmakiola.floret.time.toEpochMillis
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
+import de.jeanlucmakiola.calendula.domain.curatedForPicker
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventDetail
@@ -125,8 +126,7 @@ class CalendarRepositoryImpl @Inject constructor(
                         beginMillis = range.start.toEpochMillis(),
                         endMillis = range.endInclusive.toEpochMillis(),
                     ),
-                    switchedOffCalendarIds = invisibleCalendarIds() +
-                        prefs.pendingDisabledCalendarIds.first(),
+                    switchedOffCalendarIds = switchedOffCalendarIds(),
                 )
             },
             prefs.hiddenCalendarIds,
@@ -151,6 +151,10 @@ class CalendarRepositoryImpl @Inject constructor(
         .filterNot { it.isVisibleInSystem }
         .mapTo(mutableSetOf()) { it.id }
 
+    /** [invisibleCalendarIds] plus the switch-offs still waiting to be written. */
+    private suspend fun switchedOffCalendarIds(): Set<Long> =
+        invisibleCalendarIds() + prefs.pendingDisabledCalendarIds.first()
+
     private val calendarsLock = Mutex()
     private var cachedGeneration = -1L
     private var cachedPending: Set<Long>? = null
@@ -184,15 +188,13 @@ class CalendarRepositoryImpl @Inject constructor(
 
     override suspend fun searchEvents(query: String): List<SearchCandidate> = withContext(io) {
         if (query.isBlank()) return@withContext emptyList()
-        val excluded = prefs.hiddenCalendarIds.first() +
-            prefs.pendingDisabledCalendarIds.first() +
-            invisibleCalendarIds()
+        val excluded = prefs.hiddenCalendarIds.first() + switchedOffCalendarIds()
         dataSource.searchEvents(query)
             .let { if (excluded.isEmpty()) it else it.filterNot { c -> c.event.calendarId in excluded } }
     }
 
     override suspend fun eventColorPalette(calendarId: Long): List<EventColorOption> =
-        withContext(io) { dataSource.eventColorPalette(calendarId) }
+        withContext(io) { dataSource.publishedEventColors(calendarId).curatedForPicker() }
 
     override suspend fun createLocalCalendar(
         displayName: String,
@@ -214,16 +216,15 @@ class CalendarRepositoryImpl @Inject constructor(
 
     override suspend fun setCalendarsVisible(ids: Collection<Long>, visible: Boolean) =
         write {
-            if (dataSource.canWriteCalendars()) {
-                ids.forEach { dataSource.setCalendarVisible(it, visible) }
-                // Nothing of ours is left waiting for the provider once the
-                // write lands (and switching one back on retires its entry).
-                prefs.removePendingDisabledCalendarIds(ids)
-            } else if (visible) {
+            val canWrite = dataSource.canWriteCalendars()
+            if (canWrite) ids.forEach { dataSource.setCalendarVisible(it, visible) }
+            // Nothing of ours is left waiting for the provider once the write
+            // lands, and switching one back on retires its entry. With read-only
+            // permission a switch-off still works, app-side, and the reconciler
+            // flushes it if WRITE_CALENDAR ever arrives.
+            if (canWrite || visible) {
                 prefs.removePendingDisabledCalendarIds(ids)
             } else {
-                // Read-only permission: the switch still works, app-side, and
-                // the reconciler flushes it if WRITE_CALENDAR ever arrives.
                 prefs.addPendingDisabledCalendarIds(ids)
             }
         }

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/CalendarVisibilityReconciler.kt

@@ -4,15 +4,15 @@ import android.Manifest
 import android.content.Context
 import android.content.pm.PackageManager
 import android.util.Log
-import androidx.core.content.ContextCompat
 import dagger.hilt.EntryPoint
 import dagger.hilt.InstallIn
 import dagger.hilt.android.qualifiers.ApplicationContext
 import dagger.hilt.components.SingletonComponent
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.domain.calendarVisibilityPlan
 import de.jeanlucmakiola.calendula.domain.hasSystemHiddenCalendars
+import de.jeanlucmakiola.floret.android.hasPermission
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.withContext
@@ -47,7 +47,7 @@ class CalendarVisibilityReconciler @Inject constructor(
             // Settled ahead of the permission gate, so an update installed
             // before the first grant can't later look like an upgrade.
             if (!isUpgradeInstall()) settleNoticeOnce(pending = false)
-            if (!hasPermission(Manifest.permission.READ_CALENDAR)) return@withContext
+            if (!context.hasPermission(Manifest.permission.READ_CALENDAR)) return@withContext
             val pending = prefs.pendingDisabledCalendarIds.first()
             val noticeSettled = prefs.visibilityNoticePending.first() != null
             if (pending.isEmpty() && noticeSettled) return@withContext
@@ -56,7 +56,7 @@ class CalendarVisibilityReconciler @Inject constructor(
             // Both decisions below are one-way, so leave them to the next run.
             if (calendars.isEmpty()) return@withContext
             settleNoticeOnce(hasSystemHiddenCalendars(calendars, pending))
-            if (pending.isEmpty() || !hasPermission(Manifest.permission.WRITE_CALENDAR)) {
+            if (pending.isEmpty() || !context.hasPermission(Manifest.permission.WRITE_CALENDAR)) {
                 return@withContext
             }
             val plan = calendarVisibilityPlan(calendars, pending)
@@ -97,9 +97,6 @@ class CalendarVisibilityReconciler @Inject constructor(
         false
     }
 
-    private fun hasPermission(permission: String): Boolean =
-        ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
-
     /** Lets non-injectable entry points (the Application) reach the reconciler. */
     @EntryPoint
     @InstallIn(SingletonComponent::class)

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/ColumnReader.kt

@@ -1,6 +1,11 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
 import android.database.Cursor
+import de.jeanlucmakiola.calendula.domain.EventStatus
+import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
+import java.time.Instant
+import java.time.LocalDate
+import java.time.ZoneOffset
 
 /**
  * Read-only view over a single row's columns by index. Lets the mappers work
@@ -20,3 +25,33 @@ internal class CursorColumnReader(private val cursor: Cursor) : ColumnReader {
     override fun getInt(index: Int): Int = cursor.getInt(index)
     override fun isNull(index: Int): Boolean = cursor.isNull(index)
 }
+
+internal fun ColumnReader.getIntOrNull(index: Int): Int? = if (isNull(index)) null else getInt(index)
+
+internal fun ColumnReader.getLongOrNull(index: Int): Long? = if (isNull(index)) null else getLong(index)
+
+/**
+ * The row's end: DTEND, or DTSTART + DURATION for a recurring row, which stores
+ * no DTEND. Unclamped; a missing/blank both means a zero-length event.
+ */
+internal fun ColumnReader.endMillis(dtStartMillis: Long, dtEndIndex: Int, durationIndex: Int): Long =
+    getLongOrNull(dtEndIndex) ?: (dtStartMillis + parseRfc2445DurationMillis(getString(durationIndex)))
+
+/** STATUS shares value 0 with TENTATIVE, so an absent column must read as Confirmed. */
+internal fun ColumnReader.eventStatus(index: Int): EventStatus =
+    getIntOrNull(index)?.let(::mapEventStatus) ?: EventStatus.Confirmed
+
+/** Map every row, reading each through one [CursorColumnReader]. */
+internal inline fun <T> Cursor.mapRows(map: ColumnReader.() -> T): List<T> {
+    val reader = CursorColumnReader(this)
+    return buildList { while (moveToNext()) add(reader.map()) }
+}
+
+/** [mapRows], dropping the rows [map] returns null for. */
+internal inline fun <T : Any> Cursor.mapRowsNotNull(map: ColumnReader.() -> T?): List<T> {
+    val reader = CursorColumnReader(this)
+    return buildList { while (moveToNext()) reader.map()?.let(::add) }
+}
+
+/** The UTC calendar day of [millis] — an all-day row's date, since it sits at UTC midnight. */
+internal fun utcDate(millis: Long): LocalDate = Instant.ofEpochMilli(millis).atZone(ZoneOffset.UTC).toLocalDate()

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventDetailMapper.kt

@@ -15,9 +15,7 @@ import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.Reminder
 import de.jeanlucmakiola.calendula.domain.ReminderMethod
 import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
-import java.time.Instant
 import java.time.ZoneId
-import java.time.ZoneOffset
 
 private const val TAG = "EventDetailMapper"
 
@@ -48,11 +46,8 @@ internal fun ColumnReader.toEventDetailCore(
     // — the same trap as the pre-1970 DTSTART bug above (issue #34): it would
     // surface as the generic error screen with no way to open the event and fix
     // it. Clamp to a zero-length event instead (matching SearchMapper).
-    val end = if (isNull(EventDetailProjection.IDX_DTEND)) {
-        begin + parseRfc2445DurationMillis(getString(EventDetailProjection.IDX_DURATION))
-    } else {
-        getLong(EventDetailProjection.IDX_DTEND).coerceAtLeast(begin)
-    }
+    val end = getLongOrNull(EventDetailProjection.IDX_DTEND)?.coerceAtLeast(begin)
+        ?: (begin + parseRfc2445DurationMillis(getString(EventDetailProjection.IDX_DURATION)))
 
     // Kept raw (no untitled fallback): the detail screen substitutes its own
     // localized placeholder, and the edit form must prefill the true value.
@@ -61,11 +56,7 @@ internal fun ColumnReader.toEventDetailCore(
     // The event's own colour (null = inherits the calendar's) is kept apart
     // from the resolved display colour: the edit form needs to tell the two
     // cases apart, while the instance carries the calendar fallback for display.
-    val eventColor = if (isNull(EventDetailProjection.IDX_EVENT_COLOR)) {
-        null
-    } else {
-        getInt(EventDetailProjection.IDX_EVENT_COLOR)
-    }
+    val eventColor = getIntOrNull(EventDetailProjection.IDX_EVENT_COLOR)
     val eventColorKey = getString(EventDetailProjection.IDX_EVENT_COLOR_KEY)
     val color = eventColor ?: getInt(EventDetailProjection.IDX_CALENDAR_COLOR)
 
@@ -88,7 +79,7 @@ internal fun ColumnReader.toEventDetailCore(
     // and detail screen speak. DTSTART is UTC midnight for all-day events, so the
     // event's date is its UTC date.
     val displayReminders = if (isAllDay) {
-        val startDate = Instant.ofEpochMilli(begin).atZone(ZoneOffset.UTC).toLocalDate()
+        val startDate = utcDate(begin)
         val zone = ZoneId.systemDefault()
         reminders.map {
             it.copy(
@@ -101,14 +92,6 @@ internal fun ColumnReader.toEventDetailCore(
         reminders
     }
 
-    // STATUS shares its 0 value with STATUS_TENTATIVE, so a missing column must
-    // be distinguished from a present 0 — an absent status means "just confirmed".
-    val status = if (isNull(EventDetailProjection.IDX_STATUS)) {
-        EventStatus.Confirmed
-    } else {
-        mapEventStatus(getInt(EventDetailProjection.IDX_STATUS))
-    }
-
     return EventDetail(
         instance = instance,
         description = getString(EventDetailProjection.IDX_DESCRIPTION),
@@ -116,7 +99,7 @@ internal fun ColumnReader.toEventDetailCore(
         attendees = attendees,
         rrule = getString(EventDetailProjection.IDX_RRULE),
         reminders = displayReminders,
-        status = status,
+        status = eventStatus(EventDetailProjection.IDX_STATUS),
         // BUSY and DEFAULT are both 0, so a null column folds into the same
         // default these mappers already return — no isNull guard needed.
         availability = mapAvailability(getInt(EventDetailProjection.IDX_AVAILABILITY)),

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/EventWriteMapper.kt

@@ -372,48 +372,11 @@ internal data class ExceptionRowSnapshot(
     val exceptionEventId: Long,
     val originalInstanceMillis: Long,
     val isCancelled: Boolean,
-    val status: Int?,
-    val title: String,
-    val isAllDay: Boolean,
     val dtStartMillis: Long,
     val dtEndMillis: Long?,
     val duration: String?,
-    val timezone: String?,
-    val availability: Int,
-    val accessLevel: Int,
-    val location: String?,
-    val description: String?,
 )
 
-/**
- * Column values replaying a *modified* occurrence [snapshot] against the moved
- * series via `CONTENT_EXCEPTION_URI`. Like [buildOccurrenceExceptionValues] the
- * length travels as DURATION (the provider rejects DTEND on an exception). A
- * cancelled occurrence is written separately (ORIGINAL_INSTANCE_TIME +
- * STATUS_CANCELED) — this builder is only for the modified case.
- */
-internal fun buildCopiedExceptionValues(snapshot: ExceptionRowSnapshot): Map<String, Any?> =
-    buildMap {
-        put(CalendarContract.Events.ORIGINAL_INSTANCE_TIME, snapshot.originalInstanceMillis)
-        put(CalendarContract.Events.TITLE, snapshot.title)
-        put(CalendarContract.Events.ALL_DAY, if (snapshot.isAllDay) 1 else 0)
-        put(CalendarContract.Events.DTSTART, snapshot.dtStartMillis)
-        put(
-            CalendarContract.Events.DURATION,
-            snapshot.duration?.takeIf { it.isNotBlank() }
-                ?: rfc2445Duration(
-                    (snapshot.dtEndMillis ?: snapshot.dtStartMillis) - snapshot.dtStartMillis,
-                    snapshot.isAllDay,
-                ),
-        )
-        put(CalendarContract.Events.EVENT_TIMEZONE, snapshot.timezone ?: "UTC")
-        put(CalendarContract.Events.AVAILABILITY, snapshot.availability)
-        put(CalendarContract.Events.ACCESS_LEVEL, snapshot.accessLevel)
-        put(CalendarContract.Events.EVENT_LOCATION, snapshot.location?.ifEmpty { null })
-        put(CalendarContract.Events.DESCRIPTION, snapshot.description?.ifEmpty { null })
-        snapshot.status?.let { put(CalendarContract.Events.STATUS, it) }
-    }
-
 /**
  * Column values for a *cancelled*-occurrence exception row ("delete only this
  * event"): inserting them at `Events.CONTENT_EXCEPTION_URI/<id>` makes the
@@ -479,9 +442,24 @@ internal fun buildOccurrenceExdateValues(
     duration: String?,
     timezone: String?,
     allDay: Int,
+): Map<String, Any?> = buildOccurrencesExdateValues(
+    existingExdate, listOf(occurrenceMillis), dtStartMillis, rrule, rdate, duration, timezone, allDay,
+)
+
+/** [buildOccurrenceExdateValues] excluding every one of [occurrences] in one write. */
+internal fun buildOccurrencesExdateValues(
+    existingExdate: String?,
+    occurrences: List<Long>,
+    dtStartMillis: Long,
+    rrule: String?,
+    rdate: String?,
+    duration: String?,
+    timezone: String?,
+    allDay: Int,
 ): Map<String, Any?> = mapOf(
-    CalendarContract.Events.EXDATE to
-        mergedExdate(existingExdate, occurrenceMillis, allDay != 0, timezone),
+    CalendarContract.Events.EXDATE to occurrences.fold(existingExdate) { exdate, millis ->
+        mergedExdate(exdate, millis, allDay != 0, timezone)
+    },
     CalendarContract.Events.DTSTART to dtStartMillis,
     CalendarContract.Events.RRULE to rrule,
     CalendarContract.Events.RDATE to rdate,
@@ -631,7 +609,7 @@ internal fun exdateAfter(
  * optionally behind the parameter prefix AOSP's `RecurrenceSet` puts in front of
  * a zoned one ([exdateListZone] reads that half).
  */
-private fun exdateStamps(exdate: String?): List<String> = exdate
+internal fun exdateStamps(exdate: String?): List<String> = exdate
     ?.withoutExdateParameters()
     ?.split(',')
     ?.map { it.trim() }
@@ -901,7 +879,7 @@ internal fun buildImportedEventValues(
  */
 private fun importDuration(startMillis: Long, endMillis: Long, isAllDay: Boolean): String {
     val span = (endMillis - startMillis).coerceAtLeast(0)
-    return if (isAllDay) "P${(span / 86_400_000L).coerceAtLeast(1)}D" else "P${span / 1_000L}S"
+    return rfc2445Duration(if (isAllDay) span.coerceAtLeast(MILLIS_PER_DAY) else span, isAllDay)
 }
 
 private fun EventStatus.toProviderStatus(): Int = when (this) {

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/IcsExportMapper.kt

@@ -1,13 +1,9 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
 import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
-import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.ics.IcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.deriveIcsUid
-import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
-import java.time.Instant
 import java.time.ZoneId
-import java.time.ZoneOffset
 
 /**
  * Map one Events row (read through [EventExportProjection]) into an [IcsEvent]
@@ -33,19 +29,8 @@ internal fun ColumnReader.toIcsEvent(
     val rrule = getString(EventExportProjection.IDX_RRULE)?.takeIf { it.isNotBlank() }
     val isAllDay = getInt(EventExportProjection.IDX_ALL_DAY) != 0
 
-    // Recurring rows store DURATION instead of DTEND; reconstruct the end from it
-    // so the writer can render DTEND. A missing/blank both means a zero-length event.
-    val end = when {
-        !isNull(EventExportProjection.IDX_DTEND) -> getLong(EventExportProjection.IDX_DTEND)
-        else -> dtStart + parseRfc2445DurationMillis(getString(EventExportProjection.IDX_DURATION))
-    }
-
-    // STATUS shares value 0 with TENTATIVE, so an absent column must read as Confirmed.
-    val status = if (isNull(EventExportProjection.IDX_STATUS)) {
-        EventStatus.Confirmed
-    } else {
-        mapEventStatus(getInt(EventExportProjection.IDX_STATUS))
-    }
+    // Unclamped: the writer renders DTEND as stored.
+    val end = endMillis(dtStart, EventExportProjection.IDX_DTEND, EventExportProjection.IDX_DURATION)
 
     return IcsEvent(
         uid = deriveIcsUid(getString(EventExportProjection.IDX_UID), eventId, dtStart),
@@ -68,14 +53,14 @@ internal fun ColumnReader.toIcsEvent(
         location = getString(EventExportProjection.IDX_LOCATION),
         description = getString(EventExportProjection.IDX_DESCRIPTION),
         reminderMinutes = if (isAllDay) {
-            val startDate = Instant.ofEpochMilli(dtStart).atZone(ZoneOffset.UTC).toLocalDate()
+            val startDate = utcDate(dtStart)
             reminderMinutes.map {
                 fromProviderAllDayMinutes(it, startDate, zone, allDayReminderTimeMinutes)
             }
         } else {
             reminderMinutes
         },
-        status = status,
+        status = eventStatus(EventExportProjection.IDX_STATUS),
         availability = mapAvailability(getInt(EventExportProjection.IDX_AVAILABILITY)),
         calendarName = calendarName,
     )
@@ -112,11 +97,7 @@ internal fun exportExDates(
 ): List<String> {
     if (exdate.isNullOrBlank()) return emptyList()
     val zone = exdateListZone(exdate, eventTimezone)
-    return exdate
-        .withoutExdateParameters()
-        .split(',')
-        .map { it.trim() }
-        .filter { it.isNotEmpty() }
+    return exdateStamps(exdate)
         .map { stamp ->
             if (isAllDay) {
                 stamp.substringBefore('T')

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/InstanceMapper.kt

@@ -25,11 +25,7 @@ internal fun ColumnReader.toEventInstance(): EventInstance? {
     // string, so it belongs to the UI layer where it can be localised (#321).
     val title = getString(InstanceProjection.IDX_TITLE).orEmpty()
 
-    val color = if (isNull(InstanceProjection.IDX_EVENT_COLOR)) {
-        getInt(InstanceProjection.IDX_CALENDAR_COLOR)
-    } else {
-        getInt(InstanceProjection.IDX_EVENT_COLOR)
-    }
+    val color = getIntOrNull(InstanceProjection.IDX_EVENT_COLOR) ?: getInt(InstanceProjection.IDX_CALENDAR_COLOR)
 
     return EventInstance(
         instanceId = getLong(InstanceProjection.IDX_INSTANCE_ID),

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/Projections.kt

@@ -1,7 +1,16 @@
 package de.jeanlucmakiola.calendula.data.calendar
 
+import android.content.ContentUris
+import android.net.Uri
 import android.provider.CalendarContract
 
+/** The `Instances` table over the window [beginMillis]..[endMillis]. */
+internal fun instancesUri(beginMillis: Long, endMillis: Long): Uri =
+    CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
+        ContentUris.appendId(this, beginMillis)
+        ContentUris.appendId(this, endMillis)
+    }.build()
+
 internal object CalendarProjection {
     val COLUMNS: Array<String> = arrayOf(
         CalendarContract.Calendars._ID,
@@ -251,40 +260,26 @@ internal object MoveMasterProjection {
 
 /**
  * The exception rows of a recurring series (`ORIGINAL_ID` = the series), read to
- * replay them against a moved copy (see [ExceptionRowSnapshot]). Both modified
+ * carry them over to a moved copy (see [ExceptionRowSnapshot]). Both modified
  * occurrences and cancellations (`STATUS_CANCELED`) are read; the query filters
- * `DELETED = 0` so provider tombstones aren't replayed.
+ * `DELETED = 0` so provider tombstones aren't carried over.
  */
 internal object ExceptionProjection {
     val COLUMNS: Array<String> = arrayOf(
         CalendarContract.Events._ID,
         CalendarContract.Events.ORIGINAL_INSTANCE_TIME,
         CalendarContract.Events.STATUS,
-        CalendarContract.Events.TITLE,
-        CalendarContract.Events.ALL_DAY,
         CalendarContract.Events.DTSTART,
         CalendarContract.Events.DTEND,
         CalendarContract.Events.DURATION,
-        CalendarContract.Events.EVENT_TIMEZONE,
-        CalendarContract.Events.AVAILABILITY,
-        CalendarContract.Events.ACCESS_LEVEL,
-        CalendarContract.Events.EVENT_LOCATION,
-        CalendarContract.Events.DESCRIPTION,
     )
 
     const val IDX_ID = 0
     const val IDX_ORIGINAL_INSTANCE_TIME = 1
     const val IDX_STATUS = 2
-    const val IDX_TITLE = 3
-    const val IDX_ALL_DAY = 4
-    const val IDX_DTSTART = 5
-    const val IDX_DTEND = 6
-    const val IDX_DURATION = 7
-    const val IDX_EVENT_TIMEZONE = 8
-    const val IDX_AVAILABILITY = 9
-    const val IDX_ACCESS_LEVEL = 10
-    const val IDX_LOCATION = 11
-    const val IDX_DESCRIPTION = 12
+    const val IDX_DTSTART = 3
+    const val IDX_DTEND = 4
+    const val IDX_DURATION = 5
 }
 
 internal object AttendeeProjection {

app/src/main/java/de/jeanlucmakiola/calendula/data/calendar/SearchMapper.kt

@@ -2,7 +2,6 @@ package de.jeanlucmakiola.calendula.data.calendar
 
 import de.jeanlucmakiola.floret.time.toKotlinInstantFromEpochMillis
 import de.jeanlucmakiola.calendula.domain.EventInstance
-import de.jeanlucmakiola.calendula.domain.ics.parseRfc2445DurationMillis
 
 /**
  * Map an Events-table row (a search hit) to an [EventInstance]. Unlike the
@@ -16,17 +15,11 @@ internal fun ColumnReader.toSearchResult(): EventInstance? {
     // long-running birthdays/anniversaries still surface in search.
     if (isNull(SearchProjection.IDX_DTSTART)) return null
     val dtStart = getLong(SearchProjection.IDX_DTSTART)
-    val end = when {
-        !isNull(SearchProjection.IDX_DTEND) -> getLong(SearchProjection.IDX_DTEND)
-        else -> dtStart + parseRfc2445DurationMillis(getString(SearchProjection.IDX_DURATION))
-    }.coerceAtLeast(dtStart)
+    val end = endMillis(dtStart, SearchProjection.IDX_DTEND, SearchProjection.IDX_DURATION)
+        .coerceAtLeast(dtStart)
 
     val title = getString(SearchProjection.IDX_TITLE).orEmpty()
-    val color = if (isNull(SearchProjection.IDX_EVENT_COLOR)) {
-        getInt(SearchProjection.IDX_CALENDAR_COLOR)
-    } else {
-        getInt(SearchProjection.IDX_EVENT_COLOR)
-    }
+    val color = getIntOrNull(SearchProjection.IDX_EVENT_COLOR) ?: getInt(SearchProjection.IDX_CALENDAR_COLOR)
     val eventId = getLong(SearchProjection.IDX_ID)
 
     return EventInstance(

app/src/main/java/de/jeanlucmakiola/calendula/data/contacts/ContactSpecialDatesDataSource.kt

@@ -2,16 +2,15 @@ package de.jeanlucmakiola.calendula.data.contacts
 
 import android.Manifest
 import android.content.Context
-import android.content.pm.PackageManager
 import android.provider.ContactsContract
 import android.provider.ContactsContract.CommonDataKinds.Event
 import android.util.Log
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.domain.contacts.ContactSpecialDate
 import de.jeanlucmakiola.calendula.domain.contacts.SpecialDateType
 import de.jeanlucmakiola.calendula.domain.contacts.managedUid
 import de.jeanlucmakiola.calendula.domain.contacts.parseContactEventDate
+import de.jeanlucmakiola.floret.android.hasPermission
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -31,8 +30,7 @@ interface ContactSpecialDatesDataSource {
 
 /** Whether `READ_CONTACTS` is granted — the gate for every contacts read. */
 fun Context.hasContactsPermission(): Boolean =
-    ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) ==
-        PackageManager.PERMISSION_GRANTED
+    hasPermission(Manifest.permission.READ_CONTACTS)
 
 /** Map a `ContactsContract` event `TYPE` to our calendar bucket. */
 internal fun specialDateTypeForRawEventType(type: Int): SpecialDateType = when (type) {

app/src/main/java/de/jeanlucmakiola/calendula/data/di/DataModule.kt

@@ -24,8 +24,6 @@ import de.jeanlucmakiola.calendula.data.time.AndroidTodaySource
 import de.jeanlucmakiola.calendula.data.time.AndroidZoneSource
 import de.jeanlucmakiola.calendula.data.time.TodaySource
 import de.jeanlucmakiola.calendula.data.time.ZoneSource
-import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.Dispatchers
 import javax.inject.Singleton
 
 private val Context.calendulaDataStore: DataStore<Preferences> by preferencesDataStore(
@@ -87,8 +85,4 @@ object DataProvideModule {
     @Singleton
     fun provideDataStore(@ApplicationContext context: Context): DataStore<Preferences> =
         context.calendulaDataStore
-
-    @Provides
-    @IoDispatcher
-    fun provideIoDispatcher(): CoroutineDispatcher = Dispatchers.IO
 }

app/src/main/java/de/jeanlucmakiola/calendula/data/di/Qualifiers.kt

@@ -1,7 +0,0 @@
-package de.jeanlucmakiola.calendula.data.di
-
-import javax.inject.Qualifier
-
-@Qualifier
-@Retention(AnnotationRetention.BINARY)
-annotation class IoDispatcher

app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/CalendarPrefs.kt

@@ -1,15 +1,13 @@
 package de.jeanlucmakiola.calendula.data.prefs
 
 import androidx.datastore.core.DataStore
-import androidx.datastore.preferences.core.MutablePreferences
 import androidx.datastore.preferences.core.Preferences
-import androidx.datastore.preferences.core.booleanPreferencesKey
-import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.core.longPreferencesKey
-import androidx.datastore.preferences.core.stringPreferencesKey
+import de.jeanlucmakiola.floret.prefs.Pref
+import de.jeanlucmakiola.floret.prefs.PrefStore
+import de.jeanlucmakiola.floret.prefs.nullableBooleanPref
+import de.jeanlucmakiola.floret.prefs.nullableLongPref
+import de.jeanlucmakiola.floret.prefs.nullableStringPref
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.distinctUntilChanged
-import kotlinx.coroutines.flow.map
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -26,18 +24,13 @@ import javax.inject.Singleton
  */
 @Singleton
 class CalendarPrefs @Inject constructor(
-    private val store: DataStore<Preferences>,
+    store: DataStore<Preferences>,
 ) {
+    private val prefs = PrefStore(store)
 
-    // Both id sets are deduped: the store is shared with SettingsPrefs, so any
-    // unrelated write would otherwise re-emit an identical set.
-    val hiddenCalendarIds: Flow<Set<Long>> = store.data
-        .map { prefs -> prefs[HIDDEN_IDS_KEY].parseIds() }
-        .distinctUntilChanged()
+    val hiddenCalendarIds: Flow<Set<Long>> = prefs.flow(HIDDEN_IDS)
 
-    suspend fun setHiddenCalendarIds(ids: Set<Long>) {
-        store.edit { prefs -> prefs.writeIds(HIDDEN_IDS_KEY, ids) }
-    }
+    suspend fun setHiddenCalendarIds(ids: Set<Long>) = prefs.set(HIDDEN_IDS, ids)
 
     /**
      * Switch-offs the provider does not know about yet, because writing
@@ -48,24 +41,18 @@ class CalendarPrefs @Inject constructor(
      * second visibility model: `CalendarVisibilityReconciler` drains it entry by
      * entry as soon as the app may write, and nothing adds to it while it may.
      */
-    val pendingDisabledCalendarIds: Flow<Set<Long>> = store.data
-        .map { prefs -> prefs[DISABLED_IDS_KEY].parseIds() }
-        .distinctUntilChanged()
+    val pendingDisabledCalendarIds: Flow<Set<Long>> = prefs.flow(DISABLED_IDS)
 
-    suspend fun addPendingDisabledCalendarIds(ids: Collection<Long>) =
-        editPendingDisabled { it + ids }
+    suspend fun addPendingDisabledCalendarIds(ids: Collection<Long>) {
+        prefs.update(DISABLED_IDS) { it + ids }
+    }
 
     /**
      * Drop [ids] from the pending set, one at a time as the reconciler flushes
      * them, so a run that fails part-way never re-applies what already landed.
      */
-    suspend fun removePendingDisabledCalendarIds(ids: Collection<Long>) =
-        editPendingDisabled { it - ids.toSet() }
-
-    private suspend fun editPendingDisabled(transform: (Set<Long>) -> Set<Long>) {
-        store.edit { prefs ->
-            prefs.writeIds(DISABLED_IDS_KEY, transform(prefs[DISABLED_IDS_KEY].parseIds()))
-        }
+    suspend fun removePendingDisabledCalendarIds(ids: Collection<Long>) {
+        prefs.update(DISABLED_IDS) { it - ids.toSet() }
     }
 
     /**
@@ -73,39 +60,28 @@ class CalendarPrefs @Inject constructor(
      * owed. Null until the reconciler has evaluated it (which needs the calendar
      * permission), false once it has been shown or was never needed.
      */
-    val visibilityNoticePending: Flow<Boolean?> = store.data.map { prefs ->
-        prefs[VISIBILITY_NOTICE_KEY]
-    }
+    val visibilityNoticePending: Flow<Boolean?> = prefs.flow(VISIBILITY_NOTICE)
 
-    suspend fun setVisibilityNoticePending(pending: Boolean) {
-        store.edit { prefs -> prefs[VISIBILITY_NOTICE_KEY] = pending }
-    }
+    suspend fun setVisibilityNoticePending(pending: Boolean) = prefs.set(VISIBILITY_NOTICE, pending)
 
     /**
      * The calendar the user last created an event in; preselected in the
      * event form. Null until the first event is created.
      */
-    val lastUsedCalendarId: Flow<Long?> = store.data.map { prefs ->
-        prefs[LAST_USED_CALENDAR_KEY]
-    }
+    val lastUsedCalendarId: Flow<Long?> = prefs.flow(LAST_USED_CALENDAR)
 
-    suspend fun setLastUsedCalendarId(id: Long) {
-        store.edit { prefs -> prefs[LAST_USED_CALENDAR_KEY] = id }
-    }
+    suspend fun setLastUsedCalendarId(id: Long) = prefs.set(LAST_USED_CALENDAR, id)
 
-    companion object {
-        internal val HIDDEN_IDS_KEY = stringPreferencesKey("hidden_calendar_ids")
-        internal val DISABLED_IDS_KEY = stringPreferencesKey("disabled_calendar_ids")
-        internal val VISIBILITY_NOTICE_KEY = booleanPreferencesKey("visibility_notice_pending")
-        internal val LAST_USED_CALENDAR_KEY = longPreferencesKey("last_used_calendar_id")
+    private companion object {
+        val HIDDEN_IDS = idSetPref("hidden_calendar_ids")
+        val DISABLED_IDS = idSetPref("disabled_calendar_ids")
+        val VISIBILITY_NOTICE = nullableBooleanPref("visibility_notice_pending")
+        val LAST_USED_CALENDAR = nullableLongPref("last_used_calendar_id")
     }
 }
 
-private fun String?.parseIds(): Set<Long> = orEmpty()
-    .split(',')
-    .mapNotNull { it.trim().toLongOrNull() }
-    .toSet()
-
-private fun MutablePreferences.writeIds(key: Preferences.Key<String>, ids: Set<Long>) {
-    if (ids.isEmpty()) remove(key) else set(key, ids.sorted().joinToString(","))
-}
+/** A comma-joined id set; non-numeric tokens are dropped, and an empty set removes the key. */
+private fun idSetPref(name: String): Pref<Set<Long>> = nullableStringPref(name).map(
+    { stored -> stored.orEmpty().split(',').mapNotNull { it.trim().toLongOrNull() }.toSet() },
+    { ids -> if (ids.isEmpty()) null else ids.sorted().joinToString(",") },
+)

app/src/main/java/de/jeanlucmakiola/calendula/data/prefs/ReminderStatePrefs.kt

@@ -2,10 +2,8 @@ package de.jeanlucmakiola.calendula.data.prefs
 
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
-import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.core.longPreferencesKey
-import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.flow.map
+import de.jeanlucmakiola.floret.prefs.PrefStore
+import de.jeanlucmakiola.floret.prefs.nullableLongPref
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -20,17 +18,16 @@ import javax.inject.Singleton
  */
 @Singleton
 class ReminderStatePrefs @Inject constructor(
-    private val store: DataStore<Preferences>,
+    store: DataStore<Preferences>,
 ) {
+    private val prefs = PrefStore(store)
 
     /** The watermark, or `null` before the first scan has ever run. */
-    suspend fun lastScanMillis(): Long? = store.data.map { it[LAST_SCAN_KEY] }.first()
+    suspend fun lastScanMillis(): Long? = prefs.get(LAST_SCAN)
 
-    suspend fun setLastScanMillis(millis: Long) {
-        store.edit { prefs -> prefs[LAST_SCAN_KEY] = millis }
-    }
+    suspend fun setLastScanMillis(millis: Long) = prefs.set(LAST_SCAN, millis)
 
     private companion object {
-        val LAST_SCAN_KEY = longPreferencesKey("reminder_last_scan_millis")
+        val LAST_SCAN = nullableLongPref("reminder_last_scan_millis")
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderActionReceiver.kt

@@ -6,11 +6,8 @@ import android.content.Intent
 import androidx.core.net.toUri
 import dagger.hilt.android.AndroidEntryPoint
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
+import de.jeanlucmakiola.floret.android.goAsync
 import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 /**
@@ -44,27 +41,17 @@ class ReminderActionReceiver : BroadcastReceiver() {
                 // Cancel now so the notification doesn't linger until the alarm;
                 // the snooze delay read is the only async work.
                 notifier.cancel(alert)
-                val pendingResult = goAsync()
-                CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
-                    try {
-                        val minutes = settingsPrefs.snoozeMinutes.first()
-                        val triggerAt = System.currentTimeMillis() + minutes * 60_000L
-                        scheduler.schedule(alert, triggerAt)
-                    } finally {
-                        pendingResult.finish()
-                    }
+                goAsync {
+                    val minutes = settingsPrefs.snoozeMinutes.first()
+                    val triggerAt = System.currentTimeMillis() + minutes * 60_000L
+                    scheduler.schedule(alert, triggerAt)
                 }
             }
 
             ACTION_SHOW -> {
-                val pendingResult = goAsync()
-                CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
-                    try {
-                        if (settingsPrefs.remindersEnabled.first() && notifier.canPost()) {
-                            notifier.post(alert)
-                        }
-                    } finally {
-                        pendingResult.finish()
+                goAsync {
+                    if (settingsPrefs.remindersEnabled.first() && notifier.canPost()) {
+                        notifier.post(alert)
                     }
                 }
             }

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderAlarms.kt

@@ -4,20 +4,12 @@ import android.app.AlarmManager
 import android.app.PendingIntent
 import android.content.Context
 import android.content.Intent
-import android.os.Build
 import androidx.core.content.getSystemService
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.floret.android.setWakeup
 import javax.inject.Inject
 import javax.inject.Singleton
 
-/**
- * True on API < 31 (no restriction), and on 31+ when the exact-alarm capability
- * is held — auto-granted via `USE_EXACT_ALARM` on API 33+ (Calendula is a
- * calendar app), user-revocable on 31–32.
- */
-internal fun AlarmManager.canScheduleExactCompat(): Boolean =
-    Build.VERSION.SDK_INT < Build.VERSION_CODES.S || canScheduleExactAlarms()
-
 /**
  * Holds the app's own wake-up for the next reminder (#75). Exactly one alarm
  * exists at a time, for the earliest reminder ahead; every firing re-scans and
@@ -31,16 +23,7 @@ class ReminderAlarmScheduler @Inject constructor(
 
     fun scheduleScan(triggerAtMillis: Long) {
         val alarmManager = context.getSystemService<AlarmManager>() ?: return
-        val pendingIntent = scanPendingIntent(PendingIntent.FLAG_UPDATE_CURRENT)
-        if (alarmManager.canScheduleExactCompat()) {
-            alarmManager.setExactAndAllowWhileIdle(
-                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
-            )
-        } else {
-            alarmManager.setAndAllowWhileIdle(
-                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
-            )
-        }
+        alarmManager.setWakeup(triggerAtMillis, scanPendingIntent(PendingIntent.FLAG_UPDATE_CURRENT))
     }
 
     /** Drop the pending wake-up — reminders are off, or there is nothing to wait for. */

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderInstanceSource.kt

@@ -1,9 +1,9 @@
 package de.jeanlucmakiola.calendula.data.reminders
 
 import android.content.Context
-import android.content.ContentUris
 import android.provider.CalendarContract
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.calendula.data.calendar.instancesUri
 import de.jeanlucmakiola.calendula.domain.reminders.ReminderEventInstance
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -37,10 +37,7 @@ class ProviderReminderInstanceSource @Inject constructor(
 ) : ReminderInstanceSource {
 
     override fun occurrences(fromMillis: Long, toMillis: Long): List<ReminderEventInstance> {
-        val uri = CalendarContract.Instances.CONTENT_URI.buildUpon().apply {
-            ContentUris.appendId(this, fromMillis)
-            ContentUris.appendId(this, toMillis)
-        }.build()
+        val uri = instancesUri(fromMillis, toMillis)
         // `visible` is the flag the app's one visibility model writes (#75).
         // The status clause mirrors CalendarDataSource.instances: NULL means
         // "normal", so a bare `!= CANCELED` would drop every ordinary event.

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderNotifier.kt

@@ -5,12 +5,10 @@ import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
 import android.content.Context
-import android.content.pm.PackageManager
 import android.os.Build
 import android.util.Log
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.MainActivity
 import de.jeanlucmakiola.calendula.R
@@ -19,6 +17,7 @@ import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.is24Hour
 import de.jeanlucmakiola.calendula.data.prefs.resolveFirstDay
+import de.jeanlucmakiola.floret.android.hasPermission
 import kotlinx.coroutines.flow.first
 import kotlinx.datetime.isoDayNumber
 import java.time.DayOfWeek
@@ -48,8 +47,7 @@ class ReminderNotifier @Inject constructor(
     /** False when the user declined `POST_NOTIFICATIONS` or muted the app. */
     fun canPost(): Boolean {
         val granted = Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU ||
-            ContextCompat.checkSelfPermission(context, Manifest.permission.POST_NOTIFICATIONS) ==
-            PackageManager.PERMISSION_GRANTED
+            context.hasPermission(Manifest.permission.POST_NOTIFICATIONS)
         return granted && NotificationManagerCompat.from(context).areNotificationsEnabled()
     }
 
@@ -63,13 +61,9 @@ class ReminderNotifier @Inject constructor(
         calendarId in calendarPrefs.pendingDisabledCalendarIds.first() ||
             calendarDataSource.isCalendarVisible(calendarId) == false
 
-    /**
-     * Post [alert], unless its calendar is switched off. Returns whether the
-     * notification was put up, which the snooze re-show path uses to tell a
-     * silenced reminder from a delivered one.
-     */
-    suspend fun post(alert: ReminderAlert): Boolean {
-        if (isSilenced(alert.calendarId)) return false
+    /** Post [alert], unless its calendar is switched off. */
+    suspend fun post(alert: ReminderAlert) {
+        if (isSilenced(alert.calendarId)) return
         ensureChannel()
         val title = alert.title.ifBlank { context.getString(R.string.event_untitled) }
         val is24Hour = settingsPrefs.timeFormat.first()
@@ -122,8 +116,6 @@ class ReminderNotifier @Inject constructor(
             // POST_NOTIFICATIONS was revoked between canPost() and here.
             Log.w(TAG, "Could not post reminder for event ${alert.eventId}", e)
         }
-        // Handled either way — a retry hits the same revoked permission.
-        return true
     }
 
     /** Remove a posted reminder (snooze re-shows it later; dismiss is final). */

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderScanner.kt

@@ -2,19 +2,18 @@ package de.jeanlucmakiola.calendula.data.reminders
 
 import android.Manifest
 import android.content.Context
-import android.content.pm.PackageManager
 import android.util.Log
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.data.calendar.CalendarDataSource
 import de.jeanlucmakiola.calendula.data.calendar.withoutProviderDefaults
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.ReminderStatePrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.reminders.planReminders
 import de.jeanlucmakiola.calendula.domain.reminders.reminderQueryHorizon
 import de.jeanlucmakiola.calendula.domain.reminders.reminderWatermark
 import de.jeanlucmakiola.calendula.domain.reminders.scheduleReminders
+import de.jeanlucmakiola.floret.android.hasPermission
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.CoroutineStart
 import kotlinx.coroutines.SupervisorJob
@@ -113,9 +112,7 @@ class ReminderScanner @Inject constructor(
         alarms.scheduleScan(schedule.nextAlarmMillis)
     }
 
-    private fun hasReadCalendar(): Boolean = ContextCompat.checkSelfPermission(
-        context, Manifest.permission.READ_CALENDAR,
-    ) == PackageManager.PERMISSION_GRANTED
+    private fun hasReadCalendar(): Boolean = context.hasPermission(Manifest.permission.READ_CALENDAR)
 
     /**
      * Re-scan when the provider changes, so a saved or deleted event re-arms the

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderScheduleReceiver.kt

@@ -4,10 +4,7 @@ import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import dagger.hilt.android.AndroidEntryPoint
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
-import kotlinx.coroutines.launch
+import de.jeanlucmakiola.floret.android.goAsync
 import javax.inject.Inject
 
 /**
@@ -29,14 +26,7 @@ class ReminderScheduleReceiver : BroadcastReceiver() {
         // exported and the broadcasts it takes are protected, so any other
         // action did not come from where it claims to.
         if (intent.action !in HANDLED_ACTIONS) return
-        val pendingResult = goAsync()
-        CoroutineScope(SupervisorJob() + Dispatchers.IO).launch {
-            try {
-                scanner.scan()
-            } finally {
-                pendingResult.finish()
-            }
-        }
+        goAsync { scanner.scan() }
     }
 
     companion object {

app/src/main/java/de/jeanlucmakiola/calendula/data/reminders/ReminderSnoozeScheduler.kt

@@ -3,9 +3,9 @@ package de.jeanlucmakiola.calendula.data.reminders
 import android.app.AlarmManager
 import android.app.PendingIntent
 import android.content.Context
-import android.os.Build
 import androidx.core.content.getSystemService
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.floret.android.setWakeup
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -31,24 +31,6 @@ class ReminderSnoozeScheduler @Inject constructor(
             ReminderActionReceiver.intent(context, ReminderActionReceiver.ACTION_SHOW, alert),
             PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE,
         )
-        if (canScheduleExact(alarmManager)) {
-            alarmManager.setExactAndAllowWhileIdle(
-                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
-            )
-        } else {
-            // Exact alarms revoked (API 31–32); an inexact wake is the best
-            // available without nagging for SCHEDULE_EXACT_ALARM.
-            alarmManager.setAndAllowWhileIdle(
-                AlarmManager.RTC_WAKEUP, triggerAtMillis, pendingIntent,
-            )
-        }
+        alarmManager.setWakeup(triggerAtMillis, pendingIntent)
     }
-
-    /**
-     * True on API < 31 (no restriction), and on 31+ when the exact-alarm
-     * capability is held — auto-granted via `USE_EXACT_ALARM` on API 33+
-     * (Calendula is a calendar app), user-revocable on 31–32.
-     */
-    private fun canScheduleExact(alarmManager: AlarmManager): Boolean =
-        Build.VERSION.SDK_INT < Build.VERSION_CODES.S || alarmManager.canScheduleExactAlarms()
 }

app/src/main/java/de/jeanlucmakiola/calendula/data/time/TodaySource.kt

@@ -1,18 +1,17 @@
 package de.jeanlucmakiola.calendula.data.time
 
-import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
-import android.content.IntentFilter
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.floret.android.broadcastTicks
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.channels.awaitClose
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.distinctUntilChanged
-import kotlinx.coroutines.flow.onStart
+import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.transformLatest
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
@@ -34,21 +33,8 @@ class AndroidTodaySource @Inject constructor(
     @ApplicationContext private val context: Context,
 ) : TodaySource {
 
-    override val today: Flow<LocalDate> = callbackFlow {
-        val receiver = object : BroadcastReceiver() {
-            override fun onReceive(context: Context, intent: Intent) {
-                trySend(Unit)
-            }
-        }
-        val filter = IntentFilter().apply {
-            addAction(Intent.ACTION_DATE_CHANGED)
-            addAction(Intent.ACTION_TIME_CHANGED)
-            addAction(Intent.ACTION_TIMEZONE_CHANGED)
-        }
-        ContextCompat.registerReceiver(context, receiver, filter, ContextCompat.RECEIVER_NOT_EXPORTED)
-        awaitClose { context.unregisterReceiver(receiver) }
-    }
-        .onStart { emit(Unit) }
+    override val today: Flow<LocalDate> = context
+        .broadcastTicks(Intent.ACTION_DATE_CHANGED, Intent.ACTION_TIME_CHANGED, Intent.ACTION_TIMEZONE_CHANGED)
         .transformLatest {
             while (true) {
                 emit(currentDate())
@@ -61,3 +47,21 @@ class AndroidTodaySource @Inject constructor(
 private const val MINUTE_MILLIS = 60_000L
 
 fun currentDate(): LocalDate = Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault()).date
+
+/**
+ * Today as a hot flow seeded with [initial]. [onRollover] runs with the previous
+ * and the new date each time the day changes while collected, so a screen left
+ * open over midnight can move off yesterday (#373).
+ */
+fun Flow<LocalDate>.stateFollowingDays(
+    scope: CoroutineScope,
+    initial: LocalDate,
+    onRollover: (old: LocalDate, new: LocalDate) -> Unit,
+): StateFlow<LocalDate> {
+    var last = initial
+    return onEach { date ->
+        val old = last
+        last = date
+        if (old != date) onRollover(old, date)
+    }.stateWhileSubscribed(scope, initial)
+}

app/src/main/java/de/jeanlucmakiola/calendula/data/time/ZoneSource.kt

@@ -1,17 +1,12 @@
 package de.jeanlucmakiola.calendula.data.time
 
-import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
-import android.content.IntentFilter
-import androidx.core.content.ContextCompat
 import dagger.hilt.android.qualifiers.ApplicationContext
-import kotlinx.coroutines.channels.awaitClose
+import de.jeanlucmakiola.floret.android.broadcastTicks
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.callbackFlow
 import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.onStart
 import kotlinx.datetime.TimeZone
 import javax.inject.Inject
 
@@ -33,17 +28,7 @@ class AndroidZoneSource @Inject constructor(
     @ApplicationContext private val context: Context,
 ) : ZoneSource {
 
-    override val zone: Flow<TimeZone> = callbackFlow {
-        val receiver = object : BroadcastReceiver() {
-            override fun onReceive(context: Context, intent: Intent) {
-                trySend(Unit)
-            }
-        }
-        val filter = IntentFilter(Intent.ACTION_TIMEZONE_CHANGED)
-        ContextCompat.registerReceiver(context, receiver, filter, ContextCompat.RECEIVER_NOT_EXPORTED)
-        awaitClose { context.unregisterReceiver(receiver) }
-    }
-        .onStart { emit(Unit) }
+    override val zone: Flow<TimeZone> = context.broadcastTicks(Intent.ACTION_TIMEZONE_CHANGED)
         .map { current() }
         .distinctUntilChanged()
 

app/src/main/java/de/jeanlucmakiola/calendula/domain/EventForm.kt

@@ -148,23 +148,21 @@ enum class EventFormProblem {
 fun EventDetail.toEditForm(beginMillis: Long, endMillis: Long, zone: TimeZone): EventForm {
     // All-day events are date-anchored and carry a nominal "UTC" that is an
     // anchor, not a location, so they never pin a zone.
-    val pinnedZone = if (instance.isAllDay) {
+    val pinned = if (instance.isAllDay) {
         null
     } else {
         eventTimezone
             ?.takeIf { it != zone.id }
             // An unparseable id (a malformed sync row) can't be honoured or
             // shown; fall back to the device zone rather than failing the open.
-            ?.takeIf { runCatching { TimeZone.of(it) }.isSuccess }
+            ?.let { id -> zoneOrNull(id)?.let { id to it } }
     }
-    val formZone = pinnedZone?.let { TimeZone.of(it) } ?: zone
+    val pinnedZone = pinned?.first
+    val formZone = pinned?.second ?: zone
     val begin = Instant.fromEpochMilliseconds(beginMillis)
     val finish = Instant.fromEpochMilliseconds(endMillis)
     val (start, end) = if (instance.isAllDay) {
-        val startDate = begin.toLocalDateTime(TimeZone.UTC).date
-        val endExclusive = finish.toLocalDateTime(TimeZone.UTC).date
-        val endDate = maxOf(startDate, LocalDate.fromEpochDays(endExclusive.toEpochDays() - 1))
-        FormTime(LocalDateTime(startDate, LocalTime(9, 0))) to FormTime(LocalDateTime(endDate, LocalTime(10, 0)))
+        allDayFormTimes(begin.toLocalDateTime(TimeZone.UTC).date, finish.toLocalDateTime(TimeZone.UTC).date)
     } else {
         begin.toFormTime(formZone) to finish.toFormTime(formZone)
     }
@@ -180,7 +178,7 @@ fun EventDetail.toEditForm(beginMillis: Long, endMillis: Long, zone: TimeZone):
         reminders = reminders.map { it.minutes }.distinct().sorted(),
         availability = availability,
         accessLevel = accessLevel,
-        rrule = rrule?.removePrefix("RRULE:")?.takeIf { it.isNotBlank() },
+        rrule = rrule.normalizedRrule(),
         // The provider fills EVENT_COLOR from the key, so [color] is the
         // swatch either way; a null colour means the event inherits its
         // calendar's colour.
@@ -232,6 +230,19 @@ fun EventDetail.toEditSnapshot(beginMillis: Long, endMillis: Long, zone: TimeZon
         rowEnd = instance.end,
     )
 
+/**
+ * Form times for an all-day span stored as UTC midnights with an exclusive
+ * end: the last covered day (never before [start]), with placeholder
+ * wall-clock times kept in case the user switches the event to timed.
+ */
+internal fun allDayFormTimes(start: LocalDate, endExclusive: LocalDate?): Pair<FormTime, FormTime> {
+    val end = endExclusive?.let { maxOf(start, LocalDate.fromEpochDays(it.toEpochDays() - 1)) } ?: start
+    return FormTime(LocalDateTime(start, LocalTime(9, 0))) to FormTime(LocalDateTime(end, LocalTime(10, 0)))
+}
+
+/** The bare RRULE value the form edits; blank means none. */
+internal fun String?.normalizedRrule(): String? = this?.removePrefix("RRULE:")?.takeIf { it.isNotBlank() }
+
 /**
  * Whether this form's times mean something else in [target] — a timed event
  * pinned to another zone. False when there's nothing to disambiguate: an
@@ -243,8 +254,7 @@ fun EventDetail.toEditSnapshot(beginMillis: Long, endMillis: Long, zone: TimeZon
  */
 fun EventForm.isPinnedAwayFrom(target: TimeZone): Boolean {
     if (isAllDay) return false
-    val pinned = timezone?.let { runCatching { TimeZone.of(it) }.getOrNull() } ?: return false
-    return pinned.id != target.id
+    return resolvedZone(target).id != target.id
 }
 
 /**

app/src/main/java/de/jeanlucmakiola/calendula/domain/EventSearch.kt

@@ -1,8 +1,8 @@
 package de.jeanlucmakiola.calendula.domain
 
 import kotlinx.datetime.DateTimeUnit
-import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
+import kotlinx.datetime.YearMonth
 import kotlinx.datetime.atStartOfDayIn
 import kotlinx.datetime.number
 import kotlinx.datetime.plus
@@ -101,19 +101,13 @@ object EventSearch {
 
         val today = todayStart.toLocalDateTime(zone).date
         val matched = candidates.mapNotNull { candidate -> match(candidate, tokens, now, zone) }
-        val upcoming = { m: Matched -> m.event.spanLastDay(zone) >= today }
-        val order = compareBy<Matched> { if (upcoming(it)) 0 else 1 }
-            .thenComparator { a, b ->
-                // What is left reads forwards; what is behind us reads backwards
-                // from today, nearest first.
-                if (upcoming(a)) {
-                    a.event.dayStart(zone).compareTo(b.event.dayStart(zone))
-                } else {
-                    b.event.dayStart(zone).compareTo(a.event.dayStart(zone))
-                }
-            }
+        val (upcoming, past) = matched.partition { it.event.spanLastDay(zone) >= today }
+        // What is left reads forwards; what is behind us reads backwards from
+        // today, nearest first.
+        val ordered = upcoming.sortedBy { it.event.dayStart(zone) } +
+            past.sortedByDescending { it.event.dayStart(zone) }
 
-        val (inDescriptions, dated) = matched.sortedWith(order).partition { it.descriptionOnly }
+        val (inDescriptions, dated) = ordered.partition { it.descriptionOnly }
         return SearchResults(
             months = groupByMonth(dated, zone, todayStart),
             inDescriptions = inDescriptions.map { it.hit },
@@ -126,33 +120,18 @@ object EventSearch {
         zone: TimeZone,
         todayStart: Instant,
     ): List<SearchMonth> {
-        val currentKey = monthKey(todayStart.toLocalDateTime(zone).date)
-        return dated
-            .groupBy { monthKey(it.event.spanFirstDay(zone)) }
-            .entries
-            .sortedWith(
-                compareBy<Map.Entry<Int, List<Matched>>> {
-                    when {
-                        it.key == currentKey -> 0
-                        it.key > currentKey -> 1
-                        else -> 2
-                    }
-                }.thenComparator { a, b ->
-                    if (a.key > currentKey) a.key.compareTo(b.key) else b.key.compareTo(a.key)
-                },
+        val current = todayStart.toLocalDateTime(zone).date.let { YearMonth(it.year, it.month) }
+        val groups = dated.groupBy { m -> m.event.spanFirstDay(zone).let { YearMonth(it.year, it.month) } }
+        val (behind, ahead) = groups.keys.partition { it < current }
+        return (ahead.sorted() + behind.sortedDescending()).map { month ->
+            SearchMonth(
+                year = month.year,
+                monthNumber = month.month.number,
+                hits = groups.getValue(month).map { it.hit },
             )
-            .map { (key, entries) ->
-                SearchMonth(
-                    year = key / 12,
-                    monthNumber = key % 12 + 1,
-                    hits = entries.map { it.hit },
-                )
-            }
+        }
     }
 
-    /** Year and month as one comparable number. */
-    private fun monthKey(date: LocalDate): Int = date.year * 12 + (date.month.number - 1)
-
     private fun match(
         candidate: SearchCandidate,
         tokens: List<String>,

app/src/main/java/de/jeanlucmakiola/calendula/domain/EventShift.kt

@@ -17,12 +17,15 @@ import kotlin.time.Instant
 import kotlin.time.toJavaInstant
 import kotlin.time.toKotlinInstant
 
+/** [id] as a zone, or null when the tz database doesn't know it. */
+internal fun zoneOrNull(id: String): TimeZone? = runCatching { TimeZone.of(id) }.getOrNull()
+
 /**
  * The zone this form's wall-clock times mean, matching what the data layer
  * resolves them in at write time: the form's own pinned zone, else [deviceZone].
  */
 fun EventForm.resolvedZone(deviceZone: TimeZone): TimeZone =
-    timezone?.let { runCatching { TimeZone.of(it) }.getOrNull() } ?: deviceZone
+    timezone?.let(::zoneOrNull) ?: deviceZone
 
 /**
  * This wall-clock time in [zone], at [preferred] when the fall-back hour repeats

app/src/main/java/de/jeanlucmakiola/calendula/domain/InsertEventForm.kt

@@ -1,8 +1,5 @@
 package de.jeanlucmakiola.calendula.domain
 
-import kotlinx.datetime.LocalDate
-import kotlinx.datetime.LocalDateTime
-import kotlinx.datetime.LocalTime
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Duration.Companion.hours
@@ -35,17 +32,11 @@ fun buildInsertEventForm(
     now: Instant,
 ): EventForm {
     val (start, end) = if (isAllDay) {
-        // All-day provider times are UTC midnights with an exclusive end; show
-        // the last covered day and keep placeholder wall-clock times in case the
-        // user switches the event to timed (mirrors EventDetail.toEditForm).
         val startDate = beginMillis
             ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(TimeZone.UTC).date }
             ?: now.toLocalDateTime(zone).date
-        val endDate = endMillis
-            ?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(TimeZone.UTC).date }
-            ?.let { exclusive -> maxOf(startDate, LocalDate.fromEpochDays(exclusive.toEpochDays() - 1)) }
-            ?: startDate
-        FormTime(LocalDateTime(startDate, LocalTime(9, 0))) to FormTime(LocalDateTime(endDate, LocalTime(10, 0)))
+        val endExclusive = endMillis?.let { Instant.fromEpochMilliseconds(it).toLocalDateTime(TimeZone.UTC).date }
+        allDayFormTimes(startDate, endExclusive)
     } else {
         val startAt = beginMillis?.let(Instant::fromEpochMilliseconds) ?: nextFullHour(now)
         val endAt = endMillis?.let(Instant::fromEpochMilliseconds)?.takeIf { it >= startAt }
@@ -62,7 +53,7 @@ fun buildInsertEventForm(
         description = description.orEmpty(),
         // Bare RRULE value (Events.RRULE convention); tolerate a leading "RRULE:"
         // some callers include.
-        rrule = rrule?.removePrefix("RRULE:")?.takeIf { it.isNotBlank() },
+        rrule = rrule.normalizedRrule(),
     )
 }
 

app/src/main/java/de/jeanlucmakiola/calendula/domain/Recurrence.kt

@@ -1,5 +1,8 @@
 package de.jeanlucmakiola.calendula.domain
 
+import de.jeanlucmakiola.calendula.domain.ics.parseBasicDate
+import de.jeanlucmakiola.calendula.domain.ics.parseBasicDateTime
+import de.jeanlucmakiola.calendula.domain.ics.toUtcBasic
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.LocalDateTime
@@ -57,24 +60,13 @@ fun parseSimpleRecurrence(
     rrule: String,
     zone: TimeZone = TimeZone.currentSystemDefault(),
 ): SimpleRecurrence? {
-    val parts = rrule.removePrefix("RRULE:").split(';')
-        .filter { it.isNotBlank() }
-        .associate { token ->
-            val eq = token.indexOf('=')
-            if (eq <= 0) return null
-            token.substring(0, eq).uppercase() to token.substring(eq + 1)
-        }
+    val parts = rruleParts(rrule).associate { part -> (part.key ?: return null) to part.value }
     if (parts.keys.any { it !in setOf("FREQ", "INTERVAL", "UNTIL", "COUNT", "WKST", "BYDAY") }) {
         return null
     }
 
-    val freq = when (parts["FREQ"]?.uppercase()) {
-        "DAILY" -> RecurrenceFreq.Daily
-        "WEEKLY" -> RecurrenceFreq.Weekly
-        "MONTHLY" -> RecurrenceFreq.Monthly
-        "YEARLY" -> RecurrenceFreq.Yearly
-        else -> return null
-    }
+    val freq = RecurrenceFreq.entries.firstOrNull { it.name.equals(parts["FREQ"], ignoreCase = true) }
+        ?: return null
     val interval = parts["INTERVAL"]?.let { it.toIntOrNull()?.takeIf { n -> n >= 1 } ?: return null } ?: 1
 
     // BYDAY is simple only as plain weekday picks on a weekly rule; ordinal
@@ -124,20 +116,27 @@ fun SimpleRecurrence.toRRule(zone: TimeZone = TimeZone.currentSystemDefault()):
     when (val e = end) {
         RecurrenceEnd.Never -> Unit
         is RecurrenceEnd.Until -> {
-            val utc = LocalDateTime(e.date, LocalTime(23, 59, 59))
-                .toInstant(zone)
-                .toLocalDateTime(TimeZone.UTC)
-            append(
-                ";UNTIL=%04d%02d%02dT%02d%02d%02dZ".format(
-                    utc.year, utc.month.number, utc.day,
-                    utc.hour, utc.minute, utc.second,
-                ),
-            )
+            append(";UNTIL=")
+            append(LocalDateTime(e.date, LocalTime(23, 59, 59)).toInstant(zone).toUtcBasic())
         }
         is RecurrenceEnd.Count -> append(";COUNT=${e.times}")
     }
 }
 
+/** One `;`-separated part of an RRULE as written; [key] is null when it has no `KEY=`. */
+internal class RrulePart(val raw: String) {
+    private val eq = raw.indexOf('=')
+    val key: String? = if (eq > 0) raw.substring(0, eq).uppercase() else null
+    val value: String = if (eq > 0) raw.substring(eq + 1) else ""
+}
+
+/**
+ * [rule]'s non-blank parts, after an optional leading "RRULE:". What to do
+ * with a malformed one (reject, repair or skip) is the caller's call.
+ */
+internal fun rruleParts(rule: String): List<RrulePart> =
+    rule.removePrefix("RRULE:").split(';').filter { it.isNotBlank() }.map(::RrulePart)
+
 internal val RRULE_DAY_CODES: Map<DayOfWeek, String> = mapOf(
     DayOfWeek.MONDAY to "MO",
     DayOfWeek.TUESDAY to "TU",
@@ -165,11 +164,7 @@ fun rruleTruncatedAt(rrule: String, untilUtcMillis: Long): String {
             val key = part.substringBefore('=').trim().uppercase()
             key == "UNTIL" || key == "COUNT"
         }
-    val until = Instant.fromEpochMilliseconds(untilUtcMillis).toLocalDateTime(TimeZone.UTC)
-    val untilPart = "UNTIL=%04d%02d%02dT%02d%02d%02dZ".format(
-        until.year, until.month.number, until.day,
-        until.hour, until.minute, until.second,
-    )
+    val untilPart = "UNTIL=" + Instant.fromEpochMilliseconds(untilUtcMillis).toUtcBasic()
     return (kept + untilPart).joinToString(";")
 }
 
@@ -178,20 +173,8 @@ fun rruleTruncatedAt(rrule: String, untilUtcMillis: Long): String {
  * forms are UTC (RFC 5545); the date is taken after converting into [zone] so
  * a [toRRule]-rendered value round-trips to the day the user picked.
  */
-private fun parseUntilDate(raw: String, zone: TimeZone): LocalDate? = runCatching {
-    val date = LocalDate(
-        raw.substring(0, 4).toInt(),
-        raw.substring(4, 6).toInt(),
-        raw.substring(6, 8).toInt(),
-    )
-    if (raw.length >= 15 && raw[8] == 'T') {
-        val time = LocalTime(
-            raw.substring(9, 11).toInt(),
-            raw.substring(11, 13).toInt(),
-            raw.substring(13, 15).toInt(),
-        )
-        LocalDateTime(date, time).toInstant(TimeZone.UTC).toLocalDateTime(zone).date
-    } else {
-        date
-    }
-}.getOrNull()
+private fun parseUntilDate(raw: String, zone: TimeZone): LocalDate? {
+    val date = parseBasicDate(raw) ?: return null
+    if (raw.length < 15 || raw[8] != 'T') return date
+    return parseBasicDateTime(raw)?.toInstant(TimeZone.UTC)?.toLocalDateTime(zone)?.date
+}

app/src/main/java/de/jeanlucmakiola/calendula/domain/RecurrenceRealign.kt

@@ -19,30 +19,30 @@ import kotlinx.datetime.LocalDate
 fun realignRecurrence(rrule: String, oldStart: LocalDate, newStart: LocalDate): String? {
     if (oldStart == newStart) return rrule
     val prefix = if (rrule.startsWith("RRULE:")) "RRULE:" else ""
-    val parts = rrule.removePrefix("RRULE:").split(';').filter { it.isNotBlank() }
+    val parts = rruleParts(rrule)
     if (parts.isEmpty()) return null
+    var freq = false
     var weekly = false
+    var byDay = false
     val rebuilt = parts.map { part ->
-        val eq = part.indexOf('=')
-        if (eq <= 0) return null
-        val key = part.substring(0, eq).uppercase()
-        val value = part.substring(eq + 1).trim()
-        when (key) {
+        val value = part.value.trim()
+        when (part.key) {
             "FREQ" -> {
+                freq = true
                 weekly = value.equals("WEEKLY", ignoreCase = true)
-                part
+                part.raw
             }
             "BYDAY" -> {
+                byDay = true
                 val old = RRULE_DAY_CODES[oldStart.dayOfWeek] ?: return null
                 if (!value.equals(old, ignoreCase = true)) return null
                 "BYDAY=${RRULE_DAY_CODES.getValue(newStart.dayOfWeek)}"
             }
-            "INTERVAL", "COUNT", "UNTIL", "WKST" -> part
+            "INTERVAL", "COUNT", "UNTIL", "WKST" -> part.raw
             else -> return null
         }
     }
     // BYDAY is only simple on a weekly rule, matching parseSimpleRecurrence.
-    if (!weekly && parts.any { it.substringBefore('=').trim().uppercase() == "BYDAY" }) return null
-    if (parts.none { it.substringBefore('=').trim().uppercase() == "FREQ" }) return null
+    if (!freq || (byDay && !weekly)) return null
     return prefix + rebuilt.joinToString(";")
 }

app/src/main/java/de/jeanlucmakiola/calendula/domain/ics/BasicFormat.kt

@@ -0,0 +1,47 @@
+package de.jeanlucmakiola.calendula.domain.ics
+
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.LocalTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.format
+import kotlinx.datetime.format.char
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Instant
+
+/** RFC 5545 basic format, `yyyyMMddTHHmmss`. */
+private val BASIC_DATE_TIME = LocalDateTime.Format {
+    date(LocalDate.Formats.ISO_BASIC)
+    char('T')
+    hour()
+    minute()
+    second()
+}
+
+/** `yyyyMMdd`. */
+internal fun LocalDate.toBasic(): String = format(LocalDate.Formats.ISO_BASIC)
+
+/** `yyyyMMddTHHmmss`, floating. */
+internal fun LocalDateTime.toBasic(): String = format(BASIC_DATE_TIME)
+
+/** `yyyyMMddTHHmmssZ`, the instant in UTC. */
+internal fun Instant.toUtcBasic(): String = toLocalDateTime(TimeZone.UTC).toBasic() + "Z"
+
+/**
+ * The date in the first eight characters of a basic-format value; whatever
+ * follows (a time, a `Z`) is ignored. Null when those aren't a valid date.
+ */
+internal fun parseBasicDate(s: String): LocalDate? = runCatching {
+    LocalDate(s.substring(0, 4).toInt(), s.substring(4, 6).toInt(), s.substring(6, 8).toInt())
+}.getOrNull()
+
+/** `yyyyMMddTHHmm[ss]`; the separator isn't checked and missing seconds read as zero. */
+internal fun parseBasicDateTime(s: String): LocalDateTime? = runCatching {
+    val date = parseBasicDate(s) ?: return null
+    val time = LocalTime(
+        s.substring(9, 11).toInt(),
+        s.substring(11, 13).toInt(),
+        if (s.length >= 15) s.substring(13, 15).toInt() else 0,
+    )
+    LocalDateTime(date, time)
+}.getOrNull()

app/src/main/java/de/jeanlucmakiola/calendula/domain/ics/IcsParser.kt

@@ -2,19 +2,17 @@ package de.jeanlucmakiola.calendula.domain.ics
 
 import de.jeanlucmakiola.calendula.domain.Availability
 import de.jeanlucmakiola.calendula.domain.EventStatus
-import kotlinx.datetime.LocalDate
+import de.jeanlucmakiola.calendula.domain.zoneOrNull
 import kotlinx.datetime.LocalDateTime
-import kotlinx.datetime.LocalTime
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.atStartOfDayIn
-import kotlinx.datetime.number
 import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
 import kotlin.math.ceil
+import kotlin.time.Duration.Companion.days
+import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Instant
 
-/** Milliseconds in a calendar day; all-day times are UTC midnights, so this is exact. */
-private const val DAY_MILLIS = 86_400_000L
 private const val MINUTES_PER_DAY = 1_440
 
 /**
@@ -318,13 +316,9 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
         dtEnd: IcsDateTime?,
         duration: String?,
     ): Instant {
-        val explicit = dtEnd?.instant ?: duration?.let {
-            Instant.fromEpochMilliseconds(
-                start.instant.toEpochMilliseconds() + parseRfc2445DurationMillis(it),
-            )
-        }
+        val explicit = dtEnd?.instant ?: duration?.let { start.instant + parseRfc2445DurationMillis(it).milliseconds }
         if (!start.isAllDay) return explicit ?: start.instant
-        return explicit?.takeIf { it > start.instant } ?: start.instant.plusDays(1)
+        return explicit?.takeIf { it > start.instant } ?: (start.instant + 1.days)
     }
 
     /**
@@ -343,17 +337,17 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
      */
     private fun normalizeExDates(lines: List<IcsContentLine>, start: IcsDateTime): List<String> {
         if (lines.isEmpty()) return emptyList()
-        val startZone = runCatching { TimeZone.of(start.zoneId) }.getOrNull() ?: deviceZone
+        val startZone = zoneOrNull(start.zoneId) ?: deviceZone
         val startTime = start.instant.toLocalDateTime(startZone).time
         return lines
             .flatMap { line -> line.value.split(',').map { line to it.trim() } }
             .mapNotNull { (line, token) ->
                 when {
                     token.isEmpty() -> null
-                    start.isAllDay -> parseBasicDate(token.substringBefore('T'))?.let(::dayCode)
-                    token.contains('T') -> parseExDateTime(token, line, startZone)?.let(::utcStamp)
+                    start.isAllDay -> parseBasicDate(token.substringBefore('T'))?.toBasic()
+                    token.contains('T') -> parseExDateTime(token, line, startZone)?.toUtcBasic()
                     else -> parseBasicDate(token)
-                        ?.let { utcStamp(LocalDateTime(it, startTime).toInstant(startZone)) }
+                        ?.let { LocalDateTime(it, startTime).toInstant(startZone).toUtcBasic() }
                 }
             }
             .distinct()
@@ -373,7 +367,7 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
         val ldt = parseBasicDateTime(token.removeSuffix("Z")) ?: return null
         val zone = when {
             token.endsWith("Z") -> TimeZone.UTC
-            else -> line.params["TZID"]?.let { runCatching { TimeZone.of(it) }.getOrNull() }
+            else -> line.params["TZID"]?.let(::zoneOrNull)
                 ?: startZone
         }
         return ldt.toInstant(zone)
@@ -409,7 +403,7 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
         if (isUtc) return IcsDateTime(ldt.toInstant(TimeZone.UTC), isAllDay = false, zoneId = "UTC")
 
         val tzid = line.params["TZID"]
-        val resolved = tzid?.let { id -> runCatching { TimeZone.of(id) }.getOrNull()?.let { id to it } }
+        val resolved = tzid?.let { id -> zoneOrNull(id)?.let { id to it } }
         if (tzid != null && resolved == null) warnings.add(IcsParseWarning.UnknownTimezone)
         val (zoneId, zone) = resolved ?: (deviceZone.id to deviceZone)
         return IcsDateTime(ldt.toInstant(zone), isAllDay = false, zoneId = zoneId)
@@ -421,16 +415,6 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
         fun IcsContentLine.isBegin(component: String) =
             name == "BEGIN" && value.trim().equals(component, true)
 
-        fun Instant.plusDays(days: Int): Instant =
-            Instant.fromEpochMilliseconds(toEpochMilliseconds() + days * DAY_MILLIS)
-
-        fun dayCode(date: LocalDate): String =
-            "%04d%02d%02d".format(date.year, date.month.number, date.day)
-
-        fun utcStamp(instant: Instant): String = with(instant.toLocalDateTime(TimeZone.UTC)) {
-            "%04d%02d%02dT%02d%02d%02dZ".format(year, month.number, day, hour, minute, second)
-        }
-
         /**
          * A single-valued `CATEGORIES`, which is what the Fossify family writes
          * for the source calendar's name. A multi-item list is a tag list and
@@ -449,59 +433,26 @@ class IcsParser(private val deviceZone: TimeZone = TimeZone.currentSystemDefault
                 .takeIf { it.isNotEmpty() && !it.equals("null", true) }
         }
 
-        /** Index of the matching `END:<component>` at/after [from], or list end. */
         /**
          * Where an unterminated component's body has to stop: the next top-level
          * `VEVENT` / `VTODO` in `[from, end)`, or [end] when there is none. A
          * nested `VALARM` is part of the body and is not a boundary.
          */
-        fun indexOfNextComponent(lines: List<String>, from: Int, end: Int): Int {
-            var i = from
-            while (i < end) {
+        fun indexOfNextComponent(lines: List<String>, from: Int, end: Int): Int =
+            (from until end).firstOrNull { i ->
                 val line = parseContentLine(lines[i])
-                if (line != null && (line.isBegin("VEVENT") || line.isBegin("VTODO"))) {
-                    return i
-                }
-                i++
-            }
-            return end
-        }
+                line != null && (line.isBegin("VEVENT") || line.isBegin("VTODO"))
+            } ?: end
 
-        fun indexOfEnd(lines: List<String>, from: Int, component: String): Int {
-            var i = from
-            while (i < lines.size) {
+        /** Index of the matching `END:<component>` at/after [from], or list end. */
+        fun indexOfEnd(lines: List<String>, from: Int, component: String): Int =
+            (from until lines.size).firstOrNull { i ->
                 val line = parseContentLine(lines[i])
-                if (line != null && line.name == "END" &&
-                    line.value.trim().equals(component, true)
-                ) {
-                    return i
-                }
-                i++
-            }
-            return lines.size
-        }
+                line != null && line.name == "END" && line.value.trim().equals(component, true)
+            } ?: lines.size
 
-        fun mapIcsStatus(value: String): EventStatus = when (value.trim().uppercase()) {
-            "TENTATIVE" -> EventStatus.Tentative
-            "CANCELLED" -> EventStatus.Cancelled
-            else -> EventStatus.Confirmed
-        }
-
-        fun parseBasicDate(s: String): LocalDate? = runCatching {
-            LocalDate(s.substring(0, 4).toInt(), s.substring(4, 6).toInt(), s.substring(6, 8).toInt())
-        }.getOrNull()
-
-        fun parseBasicDateTime(s: String): LocalDateTime? = runCatching {
-            val date = LocalDate(
-                s.substring(0, 4).toInt(), s.substring(4, 6).toInt(), s.substring(6, 8).toInt(),
-            )
-            // Format is YYYYMMDD 'T' HHMMSS; seconds optional.
-            val time = LocalTime(
-                s.substring(9, 11).toInt(),
-                s.substring(11, 13).toInt(),
-                if (s.length >= 15) s.substring(13, 15).toInt() else 0,
-            )
-            LocalDateTime(date, time)
-        }.getOrNull()
+        fun mapIcsStatus(value: String): EventStatus =
+            EventStatus.entries.firstOrNull { it.name.equals(value.trim(), ignoreCase = true) }
+                ?: EventStatus.Confirmed
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/domain/ics/IcsRecurrence.kt

@@ -1,5 +1,7 @@
 package de.jeanlucmakiola.calendula.domain.ics
 
+import de.jeanlucmakiola.calendula.domain.rruleParts
+
 private val VALID_FREQ = setOf(
     "SECONDLY", "MINUTELY", "HOURLY", "DAILY", "WEEKLY", "MONTHLY", "YEARLY",
 )
@@ -79,13 +81,12 @@ fun sanitizeRrule(raw: String?): SanitizedRrule {
         return kept.takeIf { it.isNotEmpty() }?.joinToString(",")
     }
 
-    for (part in rule.split(';')) {
-        // A stray separator ("FREQ=DAILY;") normalises away; nothing was lost.
-        // A part that carries text but no '=' ("FREQ=WEEKLY;BYDAY") is a part
-        // being dropped, so it falls through and marks the rule repaired.
-        if (part.isBlank()) continue
-        val key = part.substringBefore('=', "").trim().uppercase()
-        val value = if ('=' in part) part.substringAfter('=').trim() else ""
+    // A stray separator ("FREQ=DAILY;") normalises away; nothing was lost.
+    // A part that carries text but no '=' ("FREQ=WEEKLY;BYDAY") is a part
+    // being dropped, so it falls through and marks the rule repaired.
+    for (part in rruleParts(raw.orEmpty().trim())) {
+        val key = part.key?.trim().orEmpty()
+        val value = part.value.trim()
         val kept = when {
             key.isEmpty() || value.isEmpty() -> null
             key == "FREQ" ->

app/src/main/java/de/jeanlucmakiola/calendula/domain/ics/IcsWriter.kt

@@ -2,9 +2,8 @@ package de.jeanlucmakiola.calendula.domain.ics
 
 import de.jeanlucmakiola.calendula.domain.Availability
 import de.jeanlucmakiola.calendula.domain.EventStatus
-import kotlinx.datetime.LocalDateTime
+import de.jeanlucmakiola.calendula.domain.zoneOrNull
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.number
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Instant
 
@@ -41,7 +40,7 @@ class IcsWriter(private val prodId: String = ICS_PROD_ID) {
     private fun MutableList<String>.appendEvent(event: IcsEvent, dtStamp: Instant) {
         add("BEGIN:VEVENT")
         add("UID:${event.uid}")
-        add("DTSTAMP:${utcStamp(dtStamp)}")
+        add("DTSTAMP:${dtStamp.toUtcBasic()}")
         add("SUMMARY:${escapeText(event.summary)}")
         appendTimes(event)
         event.recurrenceRule?.takeIf { it.isNotBlank() }
@@ -63,24 +62,24 @@ class IcsWriter(private val prodId: String = ICS_PROD_ID) {
 
     private fun MutableList<String>.appendTimes(event: IcsEvent) = when {
         event.isAllDay -> {
-            add("DTSTART;VALUE=DATE:${utcDate(event.start)}")
-            add("DTEND;VALUE=DATE:${utcDate(event.end)}")
+            add("DTSTART;VALUE=DATE:${event.start.toLocalDateTime(TimeZone.UTC).date.toBasic()}")
+            add("DTEND;VALUE=DATE:${event.end.toLocalDateTime(TimeZone.UTC).date.toBasic()}")
         }
         // Recurring: anchor to wall-clock in the event's own zone.
         event.recurrenceRule?.isNotBlank() == true -> {
-            val zone = runCatching { TimeZone.of(event.zoneId) }.getOrNull()
+            val zone = zoneOrNull(event.zoneId)
             if (zone != null) {
-                add("DTSTART;TZID=${event.zoneId}:${localStamp(event.start, zone)}")
-                add("DTEND;TZID=${event.zoneId}:${localStamp(event.end, zone)}")
+                add("DTSTART;TZID=${event.zoneId}:${event.start.toLocalDateTime(zone).toBasic()}")
+                add("DTEND;TZID=${event.zoneId}:${event.end.toLocalDateTime(zone).toBasic()}")
             } else {
                 // Unknown zone id → fall back to plain UTC instants.
-                add("DTSTART:${utcStamp(event.start)}")
-                add("DTEND:${utcStamp(event.end)}")
+                add("DTSTART:${event.start.toUtcBasic()}")
+                add("DTEND:${event.end.toUtcBasic()}")
             }
         }
         else -> {
-            add("DTSTART:${utcStamp(event.start)}")
-            add("DTEND:${utcStamp(event.end)}")
+            add("DTSTART:${event.start.toUtcBasic()}")
+            add("DTEND:${event.end.toUtcBasic()}")
         }
     }
 
@@ -120,20 +119,5 @@ class IcsWriter(private val prodId: String = ICS_PROD_ID) {
         // A lead time of 0 fires at start (PT0M); anything positive is "before".
         fun triggerValue(minutes: Int): String =
             if (minutes <= 0) "PT0M" else "-PT${minutes}M"
-
-        fun utcStamp(instant: Instant): String =
-            basic(instant.toLocalDateTime(TimeZone.UTC)) + "Z"
-
-        fun localStamp(instant: Instant, zone: TimeZone): String =
-            basic(instant.toLocalDateTime(zone))
-
-        fun utcDate(instant: Instant): String {
-            val dt = instant.toLocalDateTime(TimeZone.UTC)
-            return "%04d%02d%02d".format(dt.year, dt.month.number, dt.day)
-        }
-
-        fun basic(dt: LocalDateTime): String = "%04d%02d%02dT%02d%02d%02d".format(
-            dt.year, dt.month.number, dt.day, dt.hour, dt.minute, dt.second,
-        )
     }
 }

app/src/main/java/de/jeanlucmakiola/calendula/domain/ics/ParsedIcsForm.kt

@@ -1,11 +1,9 @@
 package de.jeanlucmakiola.calendula.domain.ics
 
 import de.jeanlucmakiola.calendula.domain.EventForm
-import de.jeanlucmakiola.calendula.domain.FormTime
+import de.jeanlucmakiola.calendula.domain.allDayFormTimes
+import de.jeanlucmakiola.calendula.domain.normalizedRrule
 import de.jeanlucmakiola.calendula.domain.toFormTime
-import kotlinx.datetime.LocalDate
-import kotlinx.datetime.LocalDateTime
-import kotlinx.datetime.LocalTime
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toLocalDateTime
 
@@ -23,10 +21,7 @@ import kotlinx.datetime.toLocalDateTime
  */
 fun ParsedIcsEvent.toEventForm(zone: TimeZone): EventForm {
     val (start, end) = if (isAllDay) {
-        val startDate = this.start.toLocalDateTime(TimeZone.UTC).date
-        val endExclusive = this.end.toLocalDateTime(TimeZone.UTC).date
-        val endDate = maxOf(startDate, LocalDate.fromEpochDays(endExclusive.toEpochDays() - 1))
-        FormTime(LocalDateTime(startDate, LocalTime(9, 0))) to FormTime(LocalDateTime(endDate, LocalTime(10, 0)))
+        allDayFormTimes(this.start.toLocalDateTime(TimeZone.UTC).date, this.end.toLocalDateTime(TimeZone.UTC).date)
     } else {
         this.start.toFormTime(zone) to this.end.toFormTime(zone)
     }
@@ -40,6 +35,6 @@ fun ParsedIcsEvent.toEventForm(zone: TimeZone): EventForm {
         description = description.orEmpty(),
         reminders = semanticReminderMinutes(),
         availability = availability,
-        rrule = recurrenceRule?.removePrefix("RRULE:")?.takeIf { it.isNotBlank() },
+        rrule = recurrenceRule.normalizedRrule(),
     )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/CalendarHost.kt

@@ -4,6 +4,7 @@ import androidx.activity.compose.BackHandler
 import androidx.activity.compose.PredictiveBackHandler
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.AnimatedVisibilityScope
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.animation.SharedTransitionLayout
 import androidx.compose.animation.core.SeekableTransitionState
@@ -28,6 +29,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.saveable.Saver
 import androidx.compose.runtime.saveable.listSaver
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.platform.LocalContext
@@ -39,6 +41,7 @@ import androidx.compose.ui.layout.positionInWindow
 import androidx.compose.ui.platform.LocalDensity
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.jeanlucmakiola.calendula.data.time.currentDate
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaScreen
@@ -99,7 +102,6 @@ import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.toLocalDateTime
 import kotlin.coroutines.cancellation.CancellationException
-import kotlin.time.Clock
 import kotlin.time.Instant
 
 /**
@@ -116,29 +118,18 @@ import kotlin.time.Instant
  * view remains. So back from a widget-opened screen returns to that widget's
  * view, then home; and back through pill switches walks the views in reverse.
  *
- * [requestedDetailKey] is an externally requested occurrence (a tapped
- * reminder notification routed through MainActivity): it opens the detail
- * overlay exactly like an event tap and is cleared via [onDetailKeyConsumed]
- * so a later recomposition can't re-open it. (A widget event tap instead arrives
- * as [WidgetNavRequest.OpenEvent], which also roots the back stack in the
- * widget's view.)
+ * [requests] carries what notifications, widgets and other apps asked to
+ * open. A tapped reminder's occurrence opens the detail overlay exactly like an
+ * event tap; each request is cleared once acted on so a later recomposition
+ * can't re-open it. (A widget event tap instead arrives as
+ * [WidgetNavRequest.OpenEvent], which also roots the back stack in the widget's
+ * view.)
  */
 @OptIn(ExperimentalSharedTransitionApi::class)
 @Composable
 fun CalendarHost(
+    requests: ExternalRequests,
     modifier: Modifier = Modifier,
-    requestedDetailKey: LongArray? = null,
-    onDetailKeyConsumed: () -> Unit = {},
-    widgetNavRequest: WidgetNavRequest? = null,
-    onWidgetNavConsumed: () -> Unit = {},
-    requestedImportUri: android.net.Uri? = null,
-    onImportConsumed: () -> Unit = {},
-    requestedInsertForm: EventForm? = null,
-    requestedInsertSource: ImportSource = ImportSource.Insert,
-    onInsertConsumed: () -> Unit = {},
-    onExternalFormClosed: () -> Unit = {},
-    requestedEditKey: LongArray? = null,
-    onEditKeyConsumed: () -> Unit = {},
     viewModel: CalendarHostViewModel = hiltViewModel(),
 ) {
     // Wait for the persisted default view before seeding the stack, so the app
@@ -163,7 +154,7 @@ fun CalendarHost(
     val view = viewStack.last()
     // The date every view opens on and carries along (#184); tapping a day
     // anywhere focuses it and opens the day view there.
-    val focus = rememberSaveable(saver = ViewFocusSaver) { ViewFocus(localToday()) }
+    val focus = rememberSaveable(saver = ViewFocusSaver) { ViewFocus(currentDate()) }
     // A focus still on yesterday follows the date over, so the next view opened
     // doesn't land on the old day (#373); one moved elsewhere stays put.
     val today = viewModel.today.collectAsStateWithLifecycle().value
@@ -194,27 +185,17 @@ fun CalendarHost(
     // it overlays whichever calendar view is active. We forward the tapped
     // occurrence's own times (eventId + begin + end, packed as a saveable
     // long[]) so recurring events show the correct date, not the series start.
-    // [heldKey] keeps the last shown key alive through the slide-out (when
-    // [detailKey] is cleared); it is set in the tap callback — never a [0,0,0]
-    // placeholder — so the destination never loads a bogus id=0 on first frame.
+    // Like every overlay below, it draws its last key through the slide-out
+    // ([rememberHeld]) rather than a placeholder.
     var detailKey by rememberSaveable { mutableStateOf<LongArray?>(null) }
-    var heldKey by remember { mutableStateOf<LongArray?>(null) }
-    val onOpenDetail: (EventInstance) -> Unit = { event ->
-        val key = longArrayOf(
-            event.eventId,
-            event.start.toEpochMilliseconds(),
-            event.end.toEpochMilliseconds(),
-        )
-        heldKey = key
-        detailKey = key
-    }
+    val onOpenDetail: (EventInstance) -> Unit = { event -> detailKey = event.occurrenceKey() }
 
     // A tapped reminder notification asks for a specific occurrence.
+    val requestedDetailKey = requests.detailKey
     LaunchedEffect(requestedDetailKey) {
         if (requestedDetailKey != null) {
-            heldKey = requestedDetailKey
             detailKey = requestedDetailKey
-            onDetailKeyConsumed()
+            requests.detailKey = null
         }
     }
 
@@ -238,31 +219,17 @@ fun CalendarHost(
     // calendar list rather than by preferences. Reached from both.
     var showBackup by rememberSaveable { mutableStateOf(false) }
 
-    // Event form (v1.2 create) — same held-key pattern as the detail screen:
-    // [heldCreateIso] keeps the prefill date alive through the slide-out.
-    // [createStartMinutes] is the tapped slot's start (minutes from midnight)
-    // when the form is opened from a day/week grid tap; null from the FAB.
-    var createDateIso by rememberSaveable { mutableStateOf<String?>(null) }
-    var heldCreateIso by remember { mutableStateOf<String?>(null) }
-    var createStartMinutes by rememberSaveable { mutableStateOf<Int?>(null) }
-    var heldCreateMinutes by remember { mutableStateOf<Int?>(null) }
-    // A drafted block's start and end (#153) as epoch millis. Instants rather than
-    // minutes into a day, so the form opens at the times drawn even across a DST
-    // change (#387).
-    var createDraftMillis by rememberSaveable { mutableStateOf<LongArray?>(null) }
-    var heldCreateDraftMillis by remember { mutableStateOf<LongArray?>(null) }
-    fun openCreate(date: LocalDate, startMinutes: Int?, draftMillis: LongArray?) {
-        heldCreateIso = date.toString()
-        createDateIso = date.toString()
-        heldCreateMinutes = startMinutes
-        createStartMinutes = startMinutes
-        heldCreateDraftMillis = draftMillis
-        createDraftMillis = draftMillis
+    // Event form (v1.2 create), opened on a date, a tapped slot or a drafted block.
+    var createRequest by rememberSaveable(stateSaver = createRequestSaver) {
+        mutableStateOf<CreateRequest?>(null)
     }
-    val onCreateEvent: (LocalDate, Int?) -> Unit = { date, startMinutes -> openCreate(date, startMinutes, null) }
+    fun openCreate(dateIso: String, startMinutes: Int? = null, draftMillis: LongArray? = null) {
+        createRequest = CreateRequest(dateIso, startMinutes, draftMillis)
+    }
+    val onCreateEvent: (LocalDate, Int?) -> Unit = { date, startMinutes -> openCreate(date.toString(), startMinutes) }
     val onCreateDraft: (Instant, Instant) -> Unit = { start, end ->
         val date = start.toLocalDateTime(TimeZone.currentSystemDefault()).date
-        openCreate(date, null, longArrayOf(start.toEpochMilliseconds(), end.toEpochMilliseconds()))
+        openCreate(date.toString(), draftMillis = longArrayOf(start.toEpochMilliseconds(), end.toEpochMilliseconds()))
     }
 
     // Edit form (v1.3) — reuses the detail screen's occurrence key; for
@@ -272,7 +239,6 @@ fun CalendarHost(
     // falling back to the auto-refreshing calendar is the only honest
     // destination.
     var editKey by rememberSaveable { mutableStateOf<LongArray?>(null) }
-    var heldEditKey by remember { mutableStateOf<LongArray?>(null) }
 
     // An opened/received .ics file. [ImportScreen] parses it and either opens
     // the prefilled create form (one event → [importForm]) or its own bulk
@@ -306,7 +272,7 @@ fun CalendarHost(
             importForm = null
             if (importFromRequest) {
                 importFromRequest = false
-                onExternalFormClosed()
+                requests.onExternalFormClosed()
             }
         }
     }
@@ -325,26 +291,28 @@ fun CalendarHost(
     // what tells it a *re-import of the same file* is new work and not the run
     // it already finished; a rotation keeps the number and keeps the result.
     var importSession by rememberSaveable { mutableStateOf(0) }
+    val requestedImportUri = requests.importUri
     LaunchedEffect(requestedImportUri) {
         if (requestedImportUri != null) {
             importUri = requestedImportUri
             importForceMany = false
             importSession++
-            onImportConsumed()
+            requests.importUri = null
         }
     }
     // An external ACTION_INSERT launch (another app/widget creating an event,
     // issue #30) arrives already prefilled — open it in the same create form the
     // single-event .ics path uses. [importForm] is the topmost overlay, so it
     // reveals on top of whatever was open without extra dismissal.
-    LaunchedEffect(requestedInsertForm) {
-        if (requestedInsertForm != null) {
+    val requestedInsert = requests.insert
+    LaunchedEffect(requestedInsert) {
+        if (requestedInsert != null) {
             if (importForm == null) {
-                openImportForm(requestedInsertForm, requestedInsertSource, fromRequest = true)
+                openImportForm(requestedInsert.form, requestedInsert.source, fromRequest = true)
             } else {
-                pendingInsert = requestedInsertForm to requestedInsertSource
+                pendingInsert = requestedInsert.form to requestedInsert.source
             }
-            onInsertConsumed()
+            requests.insert = null
         }
     }
 
@@ -367,21 +335,22 @@ fun CalendarHost(
     // An external "edit this event" (ACTION_EDIT, e.g. an assistant/task app or
     // widget) opens the occurrence straight in the edit form. Drop any covering
     // overlay first — the edit overlay sits below Settings/import in the Box, so
-    // without this it would open hidden underneath them. Same held-key pattern as
-    // a detail-screen "Edit" tap; a saved edit just returns to the calendar.
+    // without this it would open hidden underneath them. A saved edit just
+    // returns to the calendar.
+    val requestedEditKey = requests.editKey
     LaunchedEffect(requestedEditKey) {
         if (requestedEditKey != null) {
             dismissCoveringOverlays()
-            heldEditKey = requestedEditKey
             editKey = requestedEditKey
-            onEditKeyConsumed()
+            requests.editKey = null
         }
     }
 
     // A home-screen widget launch asks to open a date (→ day view), open an
     // event's detail, or start a create. Handled once and cleared, mirroring
-    // [requestedDetailKey]. Date/event opens root the stack in the widget's own
+    // the detail request. Date/event opens root the stack in the widget's own
     // view so backing out returns there (then home), not to the default.
+    val widgetNavRequest = requests.nav
     LaunchedEffect(widgetNavRequest) {
         if (widgetNavRequest != null) {
             navigationVersion++
@@ -392,23 +361,21 @@ fun CalendarHost(
                 // Drill the day view in over the widget's view: drop any overlay
                 // that would cover it, so the open doesn't land under Settings/form.
                 dismissCoveringOverlays()
-                createDateIso = null
+                createRequest = null
                 focus.navigateTo(LocalDate.parse(req.dateIso))
                 // No widget source (an external date tap) roots over the default
                 // home view, so backing out of the day returns home then exits.
                 viewStack = viewBaseStack(defaultView, req.source ?: defaultView).drillToDay()
-                onWidgetNavConsumed()
+                requests.nav = null
             }
             is WidgetNavRequest.OpenEvent -> {
                 // Root the stack in the widget's view, then open the occurrence
                 // detail over it (same key shape as a tapped event / reminder).
                 dismissCoveringOverlays()
-                createDateIso = null
+                createRequest = null
                 viewStack = viewBaseStack(defaultView, req.source)
-                val key = longArrayOf(req.eventId, req.beginMillis, req.endMillis)
-                heldKey = key
-                detailKey = key
-                onWidgetNavConsumed()
+                detailKey = longArrayOf(req.eventId, req.beginMillis, req.endMillis)
+                requests.nav = null
             }
             is WidgetNavRequest.OpenView -> {
                 // A widget header tap: land on a top-level view with no date
@@ -416,10 +383,10 @@ fun CalendarHost(
                 // the stack on the target (null → the default home) over the
                 // default home — so backing out returns to the default, then exits.
                 dismissCoveringOverlays()
-                createDateIso = null
-                focus.navigateTo(localToday())
+                createRequest = null
+                focus.navigateTo(currentDate())
                 viewStack = viewBaseStack(defaultView, req.view ?: defaultView)
-                onWidgetNavConsumed()
+                requests.nav = null
             }
             is WidgetNavRequest.Create -> {
                 // External "new event" entries (QS tile / launcher shortcut /
@@ -427,15 +394,8 @@ fun CalendarHost(
                 // sits below Settings/calendars in the Box, so without this it
                 // would open hidden underneath them.
                 dismissCoveringOverlays()
-                val iso = req.dateIso ?: Clock.System.now()
-                    .toLocalDateTime(TimeZone.currentSystemDefault()).date.toString()
-                heldCreateIso = iso
-                createDateIso = iso
-                heldCreateMinutes = null
-                createStartMinutes = null
-                heldCreateDraftMillis = null
-                createDraftMillis = null
-                onWidgetNavConsumed()
+                openCreate(req.dateIso ?: currentDate().toString())
+                requests.nav = null
             }
             null -> {}
         }
@@ -448,15 +408,7 @@ fun CalendarHost(
     val eventActions: EventActionsViewModel = hiltViewModel()
     val moveOutcome by reschedule.outcome.collectAsStateWithLifecycle()
     val selectionFailure by eventActions.failure.collectAsStateWithLifecycle()
-    val onEditEvent: (EventInstance) -> Unit = { event ->
-        val key = longArrayOf(
-            event.eventId,
-            event.start.toEpochMilliseconds(),
-            event.end.toEpochMilliseconds(),
-        )
-        heldEditKey = key
-        editKey = key
-    }
+    val onEditEvent: (EventInstance) -> Unit = { event -> editKey = event.occurrenceKey() }
     // A tap opens the edit form instead of the detail screen when the user chose
     // so (#178) — only for events whose calendar takes writes. Both are read at
     // tap time, so a tap before they've loaded still routes right.
@@ -494,15 +446,10 @@ fun CalendarHost(
         )
     }
 
-    val slideSpec = rememberCalendarSlideSpec()
-    // Overlays leave from the predictive-back preview (#184): shrinking on from
-    // where the gesture let go instead of snapping back and sliding off.
-    val overlayExit = predictiveBackExit()
-
     // Base-level back: pop the view stack while no overlay covers it (each overlay
     // owns its own BackHandler and takes precedence). Disabled at the home view,
     // so back there falls through to the system and exits the app.
-    val anyOverlayVisible = showSearch || detailKey != null || createDateIso != null ||
+    val anyOverlayVisible = showSearch || detailKey != null || createRequest != null ||
         editKey != null || showSettings || showCalendars || showBackup ||
         importUri != null || importForm != null
     // The view switch runs on a seekable transition, so a back gesture can scrub
@@ -696,11 +643,7 @@ fun CalendarHost(
 
         // Search overlay — below detail/edit in the Box so a tapped result's
         // detail screen draws on top, and closing it returns to the results.
-        AnimatedVisibility(
-            visible = showSearch,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
+        SlideOverlay(visible = showSearch) {
             SearchScreen(
                 onBack = { showSearch = false },
                 onEventClick = onEventClick,
@@ -708,23 +651,15 @@ fun CalendarHost(
             )
         }
 
-        // Prefer the live key; fall back to the held one only while sliding out.
-        val activeKey = detailKey ?: heldKey
-        AnimatedVisibility(
-            visible = detailKey != null,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
-            activeKey?.let { key ->
+        val shownDetailKey = rememberHeld(detailKey)
+        SlideOverlay(visible = detailKey != null) {
+            shownDetailKey?.let { key ->
                 EventDetailScreen(
                     eventId = key[0],
                     beginMillis = key[1],
                     endMillis = key[2],
                     onBack = { detailKey = null },
-                    onEdit = {
-                        heldEditKey = key
-                        editKey = key
-                    },
+                    onEdit = { editKey = key },
                     onDuplicate = { form ->
                         // Reuse the prefilled-create overlay: a duplicate is a
                         // fresh event, so it applies the default reminder like an
@@ -738,32 +673,26 @@ fun CalendarHost(
         }
 
         // Event form (v1.2) — full-screen destination, slides over the calendar.
-        AnimatedVisibility(
-            visible = createDateIso != null,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
-            (createDateIso ?: heldCreateIso)?.let { iso ->
+        val shownCreate = rememberHeld(createRequest)
+        SlideOverlay(visible = createRequest != null) {
+            shownCreate?.let { create ->
                 EventEditScreen(
-                    initialDateIso = iso,
-                    initialStartMinutes = createStartMinutes ?: heldCreateMinutes,
-                    initialDraft = createDraftMillis ?: heldCreateDraftMillis,
-                    onClose = { createDateIso = null },
-                    onSaved = { createDateIso = null },
+                    initialDateIso = create.dateIso,
+                    initialStartMinutes = create.startMinutes,
+                    initialDraft = create.draftMillis,
+                    onClose = { createRequest = null },
+                    onSaved = { createRequest = null },
                     onManageCalendars = { showCalendars = true },
-                    visible = createDateIso != null,
+                    visible = createRequest != null,
                     viewModel = hiltViewModel(key = "create"),
                 )
             }
         }
 
         // Edit form (v1.3) — slides over the detail screen.
-        AnimatedVisibility(
-            visible = editKey != null,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
-            (editKey ?: heldEditKey)?.let { key ->
+        val shownEditKey = rememberHeld(editKey)
+        SlideOverlay(visible = editKey != null) {
+            shownEditKey?.let { key ->
                 EventEditScreen(
                     initialDateIso = null,
                     editKey = key,
@@ -780,10 +709,7 @@ fun CalendarHost(
                     // below to show why, so open it.
                     onLoadFailed = {
                         editKey = null
-                        if (detailKey == null) {
-                            heldKey = key
-                            detailKey = key
-                        }
+                        if (detailKey == null) detailKey = key
                     },
                     visible = editKey != null,
                     viewModel = hiltViewModel(key = "edit"),
@@ -792,11 +718,7 @@ fun CalendarHost(
         }
 
         // Settings (M4) — full-screen destination, slides over the calendar.
-        AnimatedVisibility(
-            visible = showSettings,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
+        SlideOverlay(visible = showSettings) {
             SettingsScreen(
                 onBack = { showSettings = false },
                 onManageCalendars = { showCalendars = true },
@@ -854,11 +776,7 @@ fun CalendarHost(
 
         // Declared last so it covers every overlay that can open it: Settings,
         // both event forms, and the .ics import picker (#76).
-        AnimatedVisibility(
-            visible = showCalendars,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
+        SlideOverlay(visible = showCalendars) {
             CalendarsScreen(
                 onBack = { showCalendars = false },
                 onOpenBackup = { showBackup = true },
@@ -867,11 +785,7 @@ fun CalendarHost(
         }
 
         // Backup & restore — over the manager, since the manager links into it.
-        AnimatedVisibility(
-            visible = showBackup,
-            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
-            exit = overlayExit,
-        ) {
+        SlideOverlay(visible = showBackup) {
             // Settings can open this screen without the manager underneath, so
             // its failure states' "Manage calendars" way out has to open the
             // manager rather than just pop — popping alone lands on Settings
@@ -910,5 +824,56 @@ private val viewStackSaver = listSaver<List<CalendarView>, Int>(
     restore = { ordinals -> ordinals.map { CalendarView.entries[it] } },
 )
 
-private fun localToday(): LocalDate =
-    Clock.System.now().toLocalDateTime(TimeZone.currentSystemDefault()).date
+/**
+ * An overlay's slide-in from the end edge, leaving from the predictive-back
+ * preview (#184): shrinking on from where the gesture let go instead of
+ * snapping back and sliding off.
+ */
+@Composable
+private fun SlideOverlay(visible: Boolean, content: @Composable AnimatedVisibilityScope.() -> Unit) {
+    AnimatedVisibility(
+        visible = visible,
+        enter = slideInHorizontally(rememberCalendarSlideSpec()) { it } + fadeIn(),
+        exit = predictiveBackExit(),
+        content = content,
+    )
+}
+
+/**
+ * [live], or after it goes null the last value it had, so an overlay keeps
+ * drawing what it showed through its slide-out instead of flashing empty. Never
+ * a placeholder: until [live] is first set this is null, so a destination never
+ * loads a bogus key on its first frame. Not saved — after a recreation the
+ * saveable [live] is the value again.
+ */
+@Composable
+private fun <T : Any> rememberHeld(live: T?): T? {
+    val held = remember { HeldValue<T>() }
+    if (live != null) held.value = live
+    return live ?: held.value
+}
+
+private class HeldValue<T : Any> {
+    var value: T? = null
+}
+
+/** The detail and edit overlays' key for one occurrence: eventId, begin, end. */
+private fun EventInstance.occurrenceKey(): LongArray =
+    longArrayOf(eventId, start.toEpochMilliseconds(), end.toEpochMilliseconds())
+
+/**
+ * A create-form open: its date, plus the tapped slot's start (minutes from
+ * midnight) from a day/week grid tap, or a drafted block's start and end (#153)
+ * as epoch millis. Instants rather than minutes into a day, so the form opens at
+ * the times drawn even across a DST change (#387).
+ */
+private class CreateRequest(
+    val dateIso: String,
+    val startMinutes: Int?,
+    val draftMillis: LongArray?,
+)
+
+private val createRequestSaver = Saver<CreateRequest?, List<Any?>>(
+    save = { request -> request?.let { listOf(it.dateIso, it.startMinutes, it.draftMillis) } },
+    restore = { CreateRequest(it[0] as String, it[1] as Int?, it[2] as LongArray?) },
+)

app/src/main/java/de/jeanlucmakiola/calendula/ui/CalendarHostViewModel.kt

@@ -8,11 +8,10 @@ import de.jeanlucmakiola.calendula.data.time.TodaySource
 import de.jeanlucmakiola.calendula.data.time.currentDate
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
-import kotlinx.coroutines.flow.SharingStarted
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.LocalDate
 import javax.inject.Inject
 
@@ -29,40 +28,35 @@ class CalendarHostViewModel @Inject constructor(
 ) : ViewModel() {
 
     /** Today, kept current across midnight so the shared focus can follow it (#373). */
-    val today: StateFlow<LocalDate> = todaySource.today.stateIn(
+    val today: StateFlow<LocalDate> = todaySource.today.stateWhileSubscribed(
         scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(5_000L),
         initialValue = currentDate(),
     )
 
-    val defaultView: StateFlow<CalendarView?> = prefs.defaultView.stateIn(
+    val defaultView: StateFlow<CalendarView?> = prefs.defaultView.stateWhileSubscribed(
         scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(5_000L),
         initialValue = null,
     )
 
     /** Views the top-bar quick-switch pill cycles through, in the user's order (#24). */
     val quickSwitchViews: StateFlow<List<CalendarView>> = prefs.quickSwitchConfig
         .map { it.cycle }
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = IMPLEMENTED_VIEWS,
         )
 
     /** Order of the views in the navigation drawer (#24); every view always shown. */
     val drawerViewOrder: StateFlow<List<CalendarView>> = prefs.drawerViewOrder
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = IMPLEMENTED_VIEWS,
         )
 
     /** Whether each view's jump-to-today control lives in the top bar, not the FAB (#60). */
     val todayButtonInToolbar: StateFlow<Boolean> = prefs.todayButtonInToolbar
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = false,
         )
 
@@ -74,9 +68,8 @@ class CalendarHostViewModel @Inject constructor(
      * switched off to be rid of.
      */
     val dragToReschedule: StateFlow<Boolean> = prefs.dragToReschedule
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = false,
         )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/ExternalRequests.kt

@@ -0,0 +1,42 @@
+package de.jeanlucmakiola.calendula.ui
+
+import android.net.Uri
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import de.jeanlucmakiola.calendula.domain.EventForm
+import de.jeanlucmakiola.calendula.ui.edit.ImportSource
+
+/**
+ * What a notification, widget, shortcut or another app asked the running app to
+ * open. MainActivity fills it from each intent (singleTop + onNewIntent route a
+ * new one into the running activity); CalendarHost acts on a request and clears
+ * it, so a later recomposition can't act on it twice.
+ *
+ * [onExternalFormClosed] runs when a form opened for [insert] closes, so the
+ * activity can hand control back to the app that asked.
+ */
+@Stable
+class ExternalRequests(val onExternalFormClosed: () -> Unit = {}) {
+    /** A tapped reminder notification's occurrence (eventId, begin, end), for the detail screen. */
+    var detailKey by mutableStateOf<LongArray?>(null)
+
+    /** A home-screen widget, shortcut or tile navigation (open a date, an event, a view, or create). */
+    var nav by mutableStateOf<WidgetNavRequest?>(null)
+
+    /** An .ics file opened or shared into the app (ACTION_VIEW/SEND). */
+    var importUri by mutableStateOf<Uri?>(null)
+
+    /**
+     * A prefilled new-event form from an external ACTION_INSERT launch (#30) or
+     * shared text (#306), opened in the create form for review.
+     */
+    var insert by mutableStateOf<InsertRequest?>(null)
+
+    /** An external "edit this event" (ACTION_EDIT), in the detail key's shape. */
+    var editKey by mutableStateOf<LongArray?>(null)
+}
+
+/** A prefilled create form from an external launch, with the source it came from. */
+data class InsertRequest(val form: EventForm, val source: ImportSource)

app/src/main/java/de/jeanlucmakiola/calendula/ui/RootScreen.kt

@@ -1,7 +1,5 @@
 package de.jeanlucmakiola.calendula.ui
 
-import android.Manifest
-import android.content.pm.PackageManager
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.fadeIn
 import androidx.compose.animation.fadeOut
@@ -20,11 +18,11 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.LocalLifecycleOwner
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import androidx.core.content.ContextCompat
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleEventObserver
 import de.jeanlucmakiola.calendula.data.contacts.SpecialDatesScheduler
 import de.jeanlucmakiola.calendula.data.contacts.hasContactsPermission
+import de.jeanlucmakiola.calendula.ui.common.canReadCalendar
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarFadeSpec
 import de.jeanlucmakiola.calendula.ui.onboarding.OnboardingStep
 import de.jeanlucmakiola.calendula.ui.onboarding.OnboardingSteps
@@ -43,27 +41,12 @@ private sealed interface RootTarget {
 
 @Composable
 fun RootScreen(
+    requests: ExternalRequests,
     modifier: Modifier = Modifier,
-    requestedDetailKey: LongArray? = null,
-    onDetailKeyConsumed: () -> Unit = {},
-    widgetNavRequest: WidgetNavRequest? = null,
-    onWidgetNavConsumed: () -> Unit = {},
-    requestedImportUri: android.net.Uri? = null,
-    onImportConsumed: () -> Unit = {},
-    requestedInsertForm: de.jeanlucmakiola.calendula.domain.EventForm? = null,
-    requestedInsertSource: de.jeanlucmakiola.calendula.ui.edit.ImportSource =
-        de.jeanlucmakiola.calendula.ui.edit.ImportSource.Insert,
-    onInsertConsumed: () -> Unit = {},
-    onExternalFormClosed: () -> Unit = {},
-    requestedEditKey: LongArray? = null,
-    onEditKeyConsumed: () -> Unit = {},
 ) {
     val context = LocalContext.current
     var hasPermission by remember {
-        mutableStateOf(
-            ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CALENDAR)
-                == PackageManager.PERMISSION_GRANTED
-        )
+        mutableStateOf(context.canReadCalendar())
     }
 
     // A launch scan already covers the app coming up with the permission, so
@@ -74,9 +57,7 @@ fun RootScreen(
     DisposableEffect(lifecycle) {
         val obs = LifecycleEventObserver { _, event ->
             if (event == Lifecycle.Event.ON_RESUME) {
-                hasPermission = ContextCompat.checkSelfPermission(
-                    context, Manifest.permission.READ_CALENDAR
-                ) == PackageManager.PERMISSION_GRANTED
+                hasPermission = context.canReadCalendar()
                 // Refresh the contact special-dates mirror on foreground (the
                 // worker is debounced and no-ops when the feature is off). Gated
                 // on the permission so users without the opt-in never enqueue it.
@@ -146,19 +127,8 @@ fun RootScreen(
         when (shown) {
             RootTarget.Loading -> Unit
             RootTarget.App -> CalendarHost(
+                requests = requests,
                 modifier = modifier,
-                requestedDetailKey = requestedDetailKey,
-                onDetailKeyConsumed = onDetailKeyConsumed,
-                widgetNavRequest = widgetNavRequest,
-                onWidgetNavConsumed = onWidgetNavConsumed,
-                requestedImportUri = requestedImportUri,
-                onImportConsumed = onImportConsumed,
-                requestedInsertForm = requestedInsertForm,
-                requestedInsertSource = requestedInsertSource,
-                onInsertConsumed = onInsertConsumed,
-                onExternalFormClosed = onExternalFormClosed,
-                requestedEditKey = requestedEditKey,
-                onEditKeyConsumed = onEditKeyConsumed,
             )
             // Both halves of a transition read their position out of the live
             // plan; the one the outgoing step was drawn with is already gone.

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaRange.kt

@@ -3,8 +3,9 @@ package de.jeanlucmakiola.calendula.ui.agenda
 import de.jeanlucmakiola.floret.locale.localizedDateFormatter
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
-import java.time.YearMonth
 import java.util.Locale
+import kotlinx.datetime.toJavaLocalDate
+import kotlinx.datetime.yearMonth
 
 /**
  * How far ahead the agenda (screen or widget) shows events, starting at today.
@@ -50,7 +51,7 @@ fun AgendaRange.dayCount(anchor: LocalDate, weekStart: DayOfWeek): Int = when (t
         DAYS_PER_WEEK - sinceWeekStart
     }
     AgendaRange.ThisMonth -> {
-        val daysInMonth = YearMonth.of(anchor.year, anchor.month.ordinal + 1).lengthOfMonth()
+        val daysInMonth = anchor.yearMonth.numberOfDays
         daysInMonth - anchor.day + 1
     }
     is AgendaRange.Custom -> days.coerceIn(AgendaRange.MIN_CUSTOM_DAYS, AgendaRange.MAX_CUSTOM_DAYS)
@@ -105,8 +106,8 @@ fun agendaRangeWindowSummary(
     locale: Locale,
     monthAsSpan: Boolean = false,
 ): String {
-    val javaStart = java.time.LocalDate.of(start.year, start.month.ordinal + 1, start.day)
-    val javaEnd = java.time.LocalDate.of(end.year, end.month.ordinal + 1, end.day)
+    val javaStart = start.toJavaLocalDate()
+    val javaEnd = end.toJavaLocalDate()
     val dayMonth = localizedDateFormatter(locale, "dMMM")
     val dayMonthYear = localizedDateFormatter(locale, "dMMMy")
     return when {

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaRows.kt

@@ -1,5 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
+import androidx.annotation.StringRes
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Box
@@ -9,6 +11,8 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyListScope
+import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Coffee
@@ -30,23 +34,25 @@ import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.isDeclined
 import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
+import de.jeanlucmakiola.calendula.ui.common.ViewMorphKey
 import de.jeanlucmakiola.calendula.ui.common.declinedTitle
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.eventAccent
-import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
+import de.jeanlucmakiola.calendula.ui.common.morphEvent
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.Position
+import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.floret.identity.LocalFloretDarkTheme
+import de.jeanlucmakiola.floret.identity.animateItemMotion
 import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.floret.locale.localizedDateFormatter
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.plus
-import kotlinx.datetime.toLocalDateTime
-import kotlin.time.Instant
+import kotlinx.datetime.toJavaLocalDate
 import java.util.Locale
 
 // The agenda's row vocabulary, split out of AgendaScreen so the month view's
@@ -177,34 +183,74 @@ internal fun agendaTimeSummary(event: EventInstance, day: LocalDate, zone: TimeZ
         AgendaTimeLabel.AllDay -> stringResource(R.string.event_detail_all_day)
         is AgendaTimeLabel.Starts -> stringResource(
             R.string.agenda_span_starts,
-            formatTime(label.start, zone, is24Hour, locale),
+            formatTimeOfDay(label.start, zone, is24Hour, locale),
         )
         is AgendaTimeLabel.Ends -> stringResource(
             R.string.agenda_span_ends,
-            formatTime(label.end, zone, is24Hour, locale),
+            formatTimeOfDay(label.end, zone, is24Hour, locale),
         )
-        is AgendaTimeLabel.Range -> "${formatTime(label.start, zone, is24Hour, locale)} – " +
-            formatTime(label.end, zone, is24Hour, locale)
+        is AgendaTimeLabel.Range -> "${formatTimeOfDay(label.start, zone, is24Hour, locale)} – " +
+            formatTimeOfDay(label.end, zone, is24Hour, locale)
     }
 
     val location = event.location?.takeIf { it.isNotBlank() }
     return if (location != null) "$time · $location" else time
 }
 
-private fun formatTime(
-    instant: Instant,
-    zone: TimeZone,
-    is24Hour: Boolean,
-    locale: Locale,
-): String {
-    val t = instant.toLocalDateTime(zone).time
-    return formatTimeOfDay(t.hour, t.minute, is24Hour, locale)
-}
-
 private fun formatAgendaDate(date: LocalDate): String {
     val locale = Locale.getDefault()
-    val java = java.time.LocalDate.of(date.year, date.month.ordinal + 1, date.day)
+    val java = date.toJavaLocalDate()
     // Weekday + date in the locale's own field order (e.g. "Wed, Jun 17, 2026"
     // vs "Mi., 17. Juni 2026") rather than a hardcoded day-month-year layout.
     return localizedDateFormatter(locale, "EEEdMMMy").format(java)
 }
+
+/**
+ * The agenda's day-by-day list body: a sticky header per day, its events or a
+ * placeholder row for an event-less day, then a gap. Shared by the Agenda screen
+ * and the month view's split pane so both lists read the same.
+ */
+@OptIn(ExperimentalFoundationApi::class)
+internal fun LazyListScope.agendaDays(
+    days: List<AgendaDay>,
+    today: LocalDate,
+    zone: TimeZone,
+    @StringRes emptyText: Int,
+    onEmptyClick: (LocalDate) -> Unit,
+    dimmed: (EventInstance, LocalDate) -> Boolean,
+    onOpenDay: (LocalDate) -> Unit,
+    onEventClick: (EventInstance) -> Unit,
+) {
+    days.forEach { day ->
+        stickyHeader(key = "header-${day.date}") {
+            AgendaDayHeader(date = day.date, today = today, onOpenDay = onOpenDay)
+        }
+        if (day.events.isEmpty()) {
+            item(key = "placeholder-${day.date}") {
+                AgendaEmptyDayRow(
+                    text = stringResource(emptyText),
+                    onClick = { onEmptyClick(day.date) },
+                )
+            }
+        } else {
+            itemsIndexed(
+                items = day.events,
+                // Scope the key by day: a multi-day event appears under every
+                // day it spans, so its instanceId alone is not unique across
+                // the list (LazyColumn requires unique keys).
+                key = { _, event -> "${day.date}-${event.instanceId}" },
+            ) { index, event ->
+                AgendaEventRow(
+                    event = event,
+                    day = day.date,
+                    zone = zone,
+                    position = positionOf(index, day.events.size),
+                    dimmed = dimmed(event, day.date),
+                    modifier = animateItemMotion().morphEvent(ViewMorphKey.event(event, day.date)),
+                    onClick = { onEventClick(event) },
+                )
+            }
+        }
+        item(key = "gap-${day.date}") { Spacer(Modifier.height(8.dp)) }
+    }
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaScreen.kt

@@ -10,9 +10,6 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.snapshotFlow
 import androidx.compose.runtime.rememberUpdatedState
-import de.jeanlucmakiola.calendula.ui.common.ViewMorphKey
-import de.jeanlucmakiola.calendula.ui.common.morphEvent
-import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -26,7 +23,6 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListState
-import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Coffee
@@ -66,11 +62,9 @@ import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
 import de.jeanlucmakiola.calendula.ui.common.AppBarSpacing
 import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
-import de.jeanlucmakiola.floret.identity.animateItemMotion
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
-import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
 import de.jeanlucmakiola.floret.locale.currentLocale
 import kotlinx.coroutines.launch
@@ -379,7 +373,6 @@ internal fun AgendaContent(
     }
 }
 
-@OptIn(ExperimentalFoundationApi::class)
 @Composable
 private fun AgendaList(
     days: List<AgendaDay>,
@@ -444,39 +437,17 @@ private fun AgendaList(
         // Bottom inset clears the FAB stack so the last row stays tappable.
         contentPadding = PaddingValues(top = 8.dp, bottom = 96.dp),
     ) {
-        days.forEach { day ->
-            stickyHeader(key = "header-${day.date}") {
-                AgendaDayHeader(date = day.date, today = today, onOpenDay = onOpenDay)
-            }
-            if (day.events.isEmpty()) {
-                // An anchored, event-less today (#35) — "nothing left today".
-                item(key = "placeholder-${day.date}") {
-                    AgendaEmptyDayRow(
-                        text = stringResource(R.string.agenda_no_more_today),
-                        onClick = { onOpenDay(day.date) },
-                    )
-                }
-            } else {
-                itemsIndexed(
-                    items = day.events,
-                    // Scope the key by day: a multi-day event appears under every
-                    // day it spans, so its instanceId alone is not unique across
-                    // the list (LazyColumn requires unique keys).
-                    key = { _, event -> "${day.date}-${event.instanceId}" },
-                ) { index, event ->
-                    AgendaEventRow(
-                        event = event,
-                        day = day.date,
-                        zone = zone,
-                        position = positionOf(index, day.events.size),
-                        dimmed = dimPast && event.isPastOn(day.date, now, zone),
-                        modifier = animateItemMotion().morphEvent(ViewMorphKey.event(event, day.date)),
-                        onClick = { onEventClick(event) },
-                    )
-                }
-            }
-            item(key = "gap-${day.date}") { Spacer(Modifier.height(8.dp)) }
-        }
+        agendaDays(
+            days = days,
+            today = today,
+            zone = zone,
+            // An anchored, event-less today (#35) — "nothing left today".
+            emptyText = R.string.agenda_no_more_today,
+            onEmptyClick = onOpenDay,
+            dimmed = { event, day -> dimPast && event.isPastOn(day, now, zone) },
+            onOpenDay = onOpenDay,
+            onEventClick = onEventClick,
+        )
     }
 }
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaViewModel.kt

@@ -1,19 +1,22 @@
 package de.jeanlucmakiola.calendula.ui.agenda
 
+import de.jeanlucmakiola.calendula.ui.common.dayRange
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.firstDayOfWeek
 import de.jeanlucmakiola.calendula.data.time.TodaySource
 import de.jeanlucmakiola.calendula.data.time.currentDate
+import de.jeanlucmakiola.calendula.data.time.stateFollowingDays
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.calendarListFailure
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -24,17 +27,13 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.atStartOfDayIn
-import kotlinx.datetime.atTime
 import kotlinx.datetime.minus
 import kotlinx.datetime.plus
-import kotlinx.datetime.toInstant
 import kotlin.time.Instant
 import javax.inject.Inject
 
@@ -66,9 +65,8 @@ class AgendaViewModel @Inject constructor(
      * the screen combines it with a per-minute "now" to fade or drop past rows.
      */
     val pastEventDisplay: StateFlow<PastEventDisplay> = settingsPrefs.pastEventDisplay
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = PastEventDisplay.SHOW,
         )
 
@@ -79,9 +77,8 @@ class AgendaViewModel @Inject constructor(
      * alongside the data state like [pastEventDisplay] rather than re-querying.
      */
     val showToday: StateFlow<Boolean> = settingsPrefs.agendaShowToday
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = true,
         )
 
@@ -101,21 +98,14 @@ class AgendaViewModel @Inject constructor(
     var lastTopDate: LocalDate? = null
         private set
 
-    private var lastToday = todayDate
-
     /**
      * Today, kept current across midnight (#373). An agenda still starting on
      * yesterday moves on to the new day; one jumped elsewhere stays put.
      */
-    private val today: StateFlow<LocalDate> = todaySource.today
-        .onEach { date ->
-            val old = lastToday
-            lastToday = date
-            if (old != date && _window.value.anchor == old) {
-                _window.value = _window.value.copy(anchor = date)
-            }
+    private val today: StateFlow<LocalDate> =
+        todaySource.today.stateFollowingDays(viewModelScope, todayDate) { old, date ->
+            if (_window.value.anchor == old) _window.value = _window.value.copy(anchor = date)
         }
-        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000L), todayDate)
 
     // A transient, in-view override of the saved agenda range. Held in memory
     // (not persisted), so it survives view switches and rotation within the
@@ -156,9 +146,8 @@ class AgendaViewModel @Inject constructor(
         }
         .catch { emit(AgendaUiState.Failure(FailureReason.ProviderUnavailable)) }
         .flowOn(io)
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = AgendaUiState.Loading,
         )
 
@@ -245,8 +234,5 @@ class AgendaViewModel @Inject constructor(
 internal const val PAST_CHUNK_DAYS = 30
 
 /** Inclusive instant range from the start of [anchor] through [days] days ahead. */
-internal fun agendaRange(anchor: LocalDate, days: Int, zone: TimeZone): ClosedRange<Instant> {
-    val from = anchor.atStartOfDayIn(zone)
-    val to = anchor.plus(days, DateTimeUnit.DAY).atTime(23, 59, 59).toInstant(zone)
-    return from..to
-}
+internal fun agendaRange(anchor: LocalDate, days: Int, zone: TimeZone): ClosedRange<Instant> =
+    dayRange(anchor, anchor.plus(days, DateTimeUnit.DAY), zone)

app/src/main/java/de/jeanlucmakiola/calendula/ui/agenda/AgendaViewPreview.kt

@@ -6,8 +6,8 @@ import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.Dp
 import de.jeanlucmakiola.calendula.data.prefs.PastEventDisplay
-import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
 import de.jeanlucmakiola.calendula.ui.common.sampleAgendaEvents
+import de.jeanlucmakiola.floret.components.ScaledViewPreview
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/BackupScreen.kt

@@ -1,7 +1,6 @@
 package de.jeanlucmakiola.calendula.ui.calendars
 
 import android.net.Uri
-import android.text.format.DateUtils
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.Box
@@ -54,13 +53,17 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
 import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
 import de.jeanlucmakiola.calendula.ui.common.LocalManageCalendars
+import de.jeanlucmakiola.calendula.ui.common.orUnnamed
 import de.jeanlucmakiola.floret.components.CollapsingScaffold
 import de.jeanlucmakiola.floret.components.DialogAmountField
 import de.jeanlucmakiola.floret.components.DialogUnitDropdown
 import de.jeanlucmakiola.floret.components.FullScreenPicker
+import de.jeanlucmakiola.floret.components.GroupedHint
 import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.GroupedSectionHeader
 import de.jeanlucmakiola.floret.components.Position
 import de.jeanlucmakiola.floret.components.positionOf
+import de.jeanlucmakiola.floret.locale.relativeTimeAgo
 import java.time.LocalDate
 
 // SAF mime filter for the restore picker. Source apps hand `.ics` files out
@@ -222,8 +225,8 @@ private fun BackupContent(
     val onRestoreClick = if (canImport) onRestore else (manageCalendars ?: onRestore)
 
     if (exportable.isEmpty()) {
-        SectionHeader(stringResource(R.string.calendars_restore_header))
-        HintText(restoreSummary)
+        GroupedSectionHeader(stringResource(R.string.calendars_restore_header))
+        GroupedHint(restoreSummary, style = MaterialTheme.typography.bodySmall)
         GroupedRow(
             title = stringResource(R.string.calendars_restore_action),
             position = Position.Alone,
@@ -233,7 +236,7 @@ private fun BackupContent(
         return
     }
 
-    HintText(stringResource(R.string.calendars_backup_hint))
+    GroupedHint(stringResource(R.string.calendars_backup_hint), style = MaterialTheme.typography.bodySmall)
     GroupedRow(
         title = stringResource(R.string.calendars_backup_action),
         position = Position.Top,
@@ -272,7 +275,7 @@ private fun BackupContent(
             position = Position.Bottom,
             onClick = onEditInterval,
         )
-        HintText(backupStatusText(autoBackup.status))
+        GroupedHint(backupStatusText(autoBackup.status), style = MaterialTheme.typography.bodySmall)
     }
 }
 
@@ -309,12 +312,13 @@ private fun ExportCalendarPicker(
     FullScreenPicker(
         title = stringResource(R.string.calendars_export_title),
         onDismiss = onDismiss,
+        predictiveBack = true,
     ) {
-        HintText(stringResource(R.string.calendars_export_hint))
+        GroupedHint(stringResource(R.string.calendars_export_hint), style = MaterialTheme.typography.bodySmall)
         calendars.forEachIndexed { index, calendar ->
             val isSelected = calendar.id in selected
             GroupedRow(
-                title = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
+                title = calendar.displayName.orUnnamed(),
                 summary = calendar.description,
                 position = positionOf(index, calendars.size),
                 leading = { CalendarColorChip(calendar.color) },
@@ -376,9 +380,7 @@ private fun backupIntervalLabel(minutes: Long): String {
 @Composable
 private fun backupStatusText(status: BackupStatus): String {
     if (status.lastRun == 0L) return stringResource(R.string.calendars_auto_backup_status_never)
-    val relative = DateUtils.getRelativeTimeSpanString(
-        status.lastRun, System.currentTimeMillis(), DateUtils.MINUTE_IN_MILLIS,
-    ).toString()
+    val relative = relativeTimeAgo(status.lastRun)
     return if (status.lastSuccess) {
         stringResource(R.string.calendars_auto_backup_status_ok, relative)
     } else {

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarsScreen.kt

@@ -12,27 +12,21 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.ColumnScope
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
-import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.KeyboardArrowRight
-import androidx.compose.material.icons.automirrored.filled.Notes
 import androidx.compose.material.icons.automirrored.filled.OpenInNew
 import androidx.compose.material.icons.filled.Add
 import androidx.compose.material.icons.filled.Backup
 import androidx.compose.material.icons.filled.CalendarMonth
-import androidx.compose.material.icons.filled.Close
 import androidx.compose.material.icons.filled.Delete
 import androidx.compose.material.icons.filled.Info
 import androidx.compose.material.icons.filled.MoreVert
-import androidx.compose.material.icons.filled.Palette
 import androidx.compose.material.icons.filled.PhoneAndroid
 import androidx.compose.material.icons.filled.Visibility
 import androidx.compose.material.icons.filled.VisibilityOff
@@ -40,20 +34,14 @@ import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.Button
 import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
-import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Scaffold
 import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
-import androidx.compose.material3.Surface
-import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
-import androidx.compose.material3.TopAppBar
-import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
@@ -84,6 +72,7 @@ import de.jeanlucmakiola.calendula.domain.stateLabels
 import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.ui.common.AccountKey
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.CalendarVisibilitySwitch
 import de.jeanlucmakiola.calendula.ui.common.accountGroupTitle
 import de.jeanlucmakiola.calendula.ui.common.groupByAccount
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
@@ -93,12 +82,14 @@ import de.jeanlucmakiola.calendula.ui.common.eventInk
 import de.jeanlucmakiola.calendula.ui.common.LeadingAvatar
 import de.jeanlucmakiola.calendula.ui.common.SourceLogo
 import de.jeanlucmakiola.calendula.ui.common.curatedSourcePackage
+import de.jeanlucmakiola.calendula.ui.common.orUnnamed
 import de.jeanlucmakiola.floret.components.CollapsingScaffold
+import de.jeanlucmakiola.floret.components.GroupedHint
+import de.jeanlucmakiola.floret.components.GroupedSectionHeader
 import de.jeanlucmakiola.floret.identity.LocalFloretDarkTheme
 import de.jeanlucmakiola.floret.identity.collapseExit
 import de.jeanlucmakiola.floret.identity.expandEnter
 import de.jeanlucmakiola.floret.identity.predictiveBack
-import de.jeanlucmakiola.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.InlineTextField
 import de.jeanlucmakiola.floret.components.Position
@@ -224,7 +215,7 @@ private fun CalendarsList(
         visible = visible,
     ) {
         // What the per-calendar / per-account switches below actually do.
-        HintText(stringResource(R.string.calendars_visibility_hint))
+        GroupedHint(stringResource(R.string.calendars_visibility_hint), style = MaterialTheme.typography.bodySmall)
 
         // Local (device-only) calendars — one collapsible group. The header's
         // "+" adds a calendar; the switch enables/disables them all at once;
@@ -245,24 +236,13 @@ private fun CalendarsList(
             onToggleAll = { enabled -> onSetAccountVisible(local.map { it.id }, enabled) },
         ) {
             if (local.isEmpty()) {
-                HintText(stringResource(R.string.calendars_local_empty))
+                GroupedHint(stringResource(R.string.calendars_local_empty), style = MaterialTheme.typography.bodySmall)
             } else {
                 local.forEachIndexed { index, calendar ->
-                    val disabled = !calendar.isVisibleInSystem
-                    GroupedRow(
-                        title = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
-                        summary = calendarRowSummary(calendar),
-                        position = if (index == local.lastIndex) Position.Bottom else Position.Middle,
-                        container = MaterialTheme.colorScheme.surfaceContainerHighest,
-                        dimmed = disabled,
-                        leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
-                        trailing = {
-                            EnableSwitch(
-                                calendarName = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
-                                enabled = !disabled,
-                                onToggle = { enabled -> onSetVisible(calendar.id, enabled) },
-                            )
-                        },
+                    CalendarManagerRow(
+                        calendar = calendar,
+                        last = index == local.lastIndex,
+                        onSetVisible = onSetVisible,
                         onClick = { onEdit(calendar) },
                     )
                 }
@@ -291,8 +271,8 @@ private fun CalendarsList(
         // Synced calendars — read-only, grouped by account. Each account is a
         // collapsible group whose header opens the source app (icon) and toggles
         // all of its calendars at once (switch).
-        SectionHeader(stringResource(R.string.calendars_synced_header))
-        HintText(stringResource(R.string.calendars_synced_hint))
+        GroupedSectionHeader(stringResource(R.string.calendars_synced_header))
+        GroupedHint(stringResource(R.string.calendars_synced_hint), style = MaterialTheme.typography.bodySmall)
         synced
             .groupByAccount()
             .forEach { group ->
@@ -333,27 +313,10 @@ private fun CalendarsList(
                     // bottom, dimmed and switchless.
                     val ordered = cals.orderedForManager()
                     ordered.forEachIndexed { index, calendar ->
-                        val disabled = !calendar.isVisibleInSystem || calendar.isNotSynced
-                        GroupedRow(
-                            title = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
-                            summary = calendarRowSummary(calendar),
-                            position = if (index == ordered.lastIndex) Position.Bottom else Position.Middle,
-                            container = MaterialTheme.colorScheme.surfaceContainerHighest,
-                            dimmed = disabled,
-                            leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
-                            trailing = if (calendar.hasVisibilitySwitch) {
-                                {
-                                    EnableSwitch(
-                                        calendarName = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
-                                        enabled = calendar.isVisibleInSystem,
-                                        onToggle = { enabled ->
-                                            onSetVisible(calendar.id, enabled)
-                                        },
-                                    )
-                                }
-                            } else {
-                                null
-                            },
+                        CalendarManagerRow(
+                            calendar = calendar,
+                            last = index == ordered.lastIndex,
+                            onSetVisible = onSetVisible,
                         )
                     }
                 }
@@ -692,17 +655,37 @@ private fun calendarRowSummary(calendar: CalendarSource): String? {
  * `Calendars.VISIBLE`. Unchecked drops the calendar out of every surface and
  * stops its reminders. Carries its own content description.
  */
+/**
+ * One calendar in a group: dimmed while switched off or not syncing, with the
+ * visibility switch only where it can change anything.
+ */
 @Composable
-private fun EnableSwitch(
-    calendarName: String,
-    enabled: Boolean,
-    onToggle: (Boolean) -> Unit,
+private fun CalendarManagerRow(
+    calendar: CalendarSource,
+    last: Boolean,
+    onSetVisible: (Long, Boolean) -> Unit,
+    onClick: (() -> Unit)? = null,
 ) {
-    val label = stringResource(R.string.calendars_visibility_a11y, calendarName)
-    Switch(
-        checked = enabled,
-        onCheckedChange = onToggle,
-        modifier = Modifier.semantics { contentDescription = label },
+    val disabled = !calendar.isVisibleInSystem || calendar.isNotSynced
+    GroupedRow(
+        title = calendar.displayName.orUnnamed(),
+        summary = calendarRowSummary(calendar),
+        position = if (last) Position.Bottom else Position.Middle,
+        container = MaterialTheme.colorScheme.surfaceContainerHighest,
+        dimmed = disabled,
+        leading = { CalendarColorChip(calendar.color, dimIf(disabled)) },
+        trailing = if (calendar.hasVisibilitySwitch) {
+            {
+                CalendarVisibilitySwitch(
+                    calendarName = calendar.displayName.orUnnamed(),
+                    enabled = calendar.isVisibleInSystem,
+                    onToggle = { enabled -> onSetVisible(calendar.id, enabled) },
+                )
+            }
+        } else {
+            null
+        },
+        onClick = onClick,
     )
 }
 
@@ -841,33 +824,6 @@ private fun CalendarGroupMenu(
 }
 
 
-@Composable
-internal fun SectionHeader(text: String) {
-    Text(
-        text = text,
-        style = MaterialTheme.typography.labelLarge,
-        color = MaterialTheme.colorScheme.primary,
-        // The cards' own edge, so header and group share a left margin.
-        modifier = Modifier.padding(
-            start = GroupedListInset,
-            end = GroupedListInset,
-            top = 16.dp,
-            bottom = 4.dp,
-        ),
-    )
-}
-
-@Composable
-internal fun HintText(text: String) {
-    Text(
-        text = text,
-        style = MaterialTheme.typography.bodySmall,
-        color = MaterialTheme.colorScheme.onSurfaceVariant,
-        modifier = Modifier.padding(horizontal = GroupedListInset, vertical = 4.dp),
-    )
-}
-
-
 /**
  * Pick the app to open for managing a synced calendar's account. The account's
  * own authenticator package (resolved from [AccountManager], no permission

app/src/main/java/de/jeanlucmakiola/calendula/ui/calendars/CalendarsViewModel.kt

@@ -9,16 +9,16 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.data.backup.BackupScheduler
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.data.prefs.BackupStatus
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.catch
@@ -26,7 +26,6 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlin.coroutines.cancellation.CancellationException
@@ -52,9 +51,8 @@ class CalendarsViewModel @Inject constructor(
         repository.calendars()
             .catch { emit(emptyList()) }
             .flowOn(io)
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = emptyList(),
             )
 
@@ -68,9 +66,8 @@ class CalendarsViewModel @Inject constructor(
             .map { backupUiState(it) }
             .catch { emit(BackupUiState.Failure(FailureReason.ProviderUnavailable)) }
             .flowOn(io)
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = BackupUiState.Loading,
             )
 
@@ -84,9 +81,8 @@ class CalendarsViewModel @Inject constructor(
         AutoBackupUiState(enabled, interval, folder, status)
     }
         .flowOn(io)
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = AutoBackupUiState(),
         )
 
@@ -103,9 +99,8 @@ class CalendarsViewModel @Inject constructor(
         if (!enabled) emptySet() else sources.filter { it.isManaged }.map { it.id }.toSet()
     }
         .flowOn(io)
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = emptySet(),
         )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/AccountGroups.kt

@@ -57,7 +57,7 @@ fun List<CalendarSource>.groupByAccount(): List<CalendarAccountGroup> {
  */
 @Composable
 fun accountGroupTitle(group: CalendarAccountGroup): String {
-    val label = group.label.ifBlank { stringResource(R.string.calendar_unnamed) }
+    val label = group.label.orUnnamed()
     return if (!group.ambiguous) {
         label
     } else {

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarChrome.kt

@@ -77,6 +77,8 @@ class EventSelection(
     val event: EventInstance,
     val dismiss: () -> Unit,
     val create: (() -> Unit)? = null,
+    /** The event at the times an ongoing move or resize would give it, else null. */
+    val preview: () -> EventInstance? = { null },
 )
 
 /** The screen on show's [ScreenChrome] and [ScreenActions], for the host to draw. */
@@ -126,10 +128,12 @@ fun PublishSelection(
     compact: Boolean,
     onDismiss: () -> Unit,
     onCreate: (() -> Unit)? = null,
+    preview: () -> EventInstance? = { null },
 ) {
     val slot = LocalChromeSlot.current ?: return
     val currentDismiss by rememberUpdatedState(onDismiss)
     val currentCreate by rememberUpdatedState(onCreate)
+    val currentPreview by rememberUpdatedState(preview)
     val drafted = onCreate != null
     val selection = remember(event, drafted) {
         event?.let {
@@ -137,6 +141,7 @@ fun PublishSelection(
                 event = it,
                 dismiss = { currentDismiss() },
                 create = if (drafted) ({ currentCreate?.invoke() }) else null,
+                preview = { currentPreview() },
             )
         }
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarPickerGroups.kt

@@ -34,7 +34,6 @@ import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.Position
-import de.jeanlucmakiola.floret.components.SelectedCheck
 
 /**
  * The app's single "which calendar" selection list, shared by the event editor
@@ -114,17 +113,11 @@ private fun CalendarPickerGroup(
         leading = leading,
     )
     calendars.forEachIndexed { index, calendar ->
-        val isSelected = calendar.id == selectedId
         GroupedRow(
-            title = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
+            title = calendar.displayName.orUnnamed(),
             position = if (index == calendars.lastIndex) Position.Bottom else Position.Middle,
-            selected = isSelected,
+            checked = calendar.id == selectedId,
             leading = { CalendarColorChip(calendar.color) },
-            trailing = if (isSelected) {
-                { SelectedCheck() }
-            } else {
-                null
-            },
             onClick = { onSelect(calendar.id) },
         )
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarText.kt

@@ -3,10 +3,12 @@ package de.jeanlucmakiola.calendula.ui.common
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.text.rememberTextMeasurer
 import androidx.compose.ui.text.style.LineHeightStyle
 import androidx.compose.ui.unit.Dp
+import de.jeanlucmakiola.calendula.R
 
 /**
  * The calendar surfaces' line-height treatment. Material wraps an 11sp glyph in
@@ -55,3 +57,7 @@ fun rememberTrimmedLineHeight(style: TextStyle): Dp {
         with(density) { measurer.measure(LINE_SAMPLE, style.trimmedLines()).size.height.toDp() }
     }
 }
+
+/** A calendar or account name, or the "unnamed" label when it is blank. */
+@Composable
+fun String.orUnnamed(): String = ifBlank { stringResource(R.string.calendar_unnamed) }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/CalendarVisibilitySwitch.kt

@@ -0,0 +1,24 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.material3.Switch
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
+import de.jeanlucmakiola.calendula.R
+
+/** The per-row switch writing the device's own `Calendars.VISIBLE`, as Settings does (#75). */
+@Composable
+fun CalendarVisibilitySwitch(
+    calendarName: String,
+    enabled: Boolean,
+    onToggle: (Boolean) -> Unit,
+) {
+    val label = stringResource(R.string.calendars_visibility_a11y, calendarName)
+    Switch(
+        checked = enabled,
+        onCheckedChange = onToggle,
+        modifier = Modifier.semantics { contentDescription = label },
+    )
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/DayRange.kt

@@ -0,0 +1,22 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import kotlinx.datetime.DateTimeUnit
+import kotlinx.datetime.DayOfWeek
+import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.atStartOfDayIn
+import kotlinx.datetime.atTime
+import kotlinx.datetime.minus
+import kotlinx.datetime.toInstant
+import kotlin.time.Instant
+
+/** Instant range from the start of [first] through the last second of [last] in [zone]. */
+internal fun dayRange(first: LocalDate, last: LocalDate, zone: TimeZone): ClosedRange<Instant> =
+    first.atStartOfDayIn(zone)..last.atTime(23, 59, 59).toInstant(zone)
+
+/** Beginning of the week (at [weekStart]) that contains this date. */
+internal fun LocalDate.startOfWeek(weekStart: DayOfWeek): LocalDate {
+    // DayOfWeek.ordinal: MONDAY=0..SUNDAY=6 → identical to ISO ordering.
+    val offset = ((dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7
+    return minus(offset, DateTimeUnit.DAY)
+}

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/EventActions.kt

@@ -3,7 +3,6 @@ package de.jeanlucmakiola.calendula.ui.common
 import android.Manifest
 import android.content.Context
 import android.content.Intent
-import android.content.pm.PackageManager
 import android.net.Uri
 import android.util.Log
 import androidx.activity.compose.rememberLauncherForActivityResult
@@ -23,7 +22,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
-import androidx.core.content.ContextCompat
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
@@ -32,6 +30,7 @@ import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.ics.IcsWriter
 import de.jeanlucmakiola.calendula.domain.ics.toShareIcsEvent
+import de.jeanlucmakiola.floret.android.hasPermission
 import de.jeanlucmakiola.floret.components.OptionCard
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.time.Clock
@@ -73,10 +72,13 @@ suspend fun CalendarRepository.deleteEvent(
 /** How a [tryDeleteEvent] ended. */
 enum class DeleteOutcome { Deleted, Gone, NeedsPermission, Failed }
 
+/** Whether this install may read the calendar at all. */
+fun Context.canReadCalendar(): Boolean =
+    hasPermission(Manifest.permission.READ_CALENDAR)
+
 /** Whether this install may write to the calendar; v1.0 installs only hold read access. */
 fun Context.canWriteCalendar(): Boolean =
-    ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_CALENDAR) ==
-        PackageManager.PERMISSION_GRANTED
+    hasPermission(Manifest.permission.WRITE_CALENDAR)
 
 /** [deleteEvent], with the provider's failures mapped to a [DeleteOutcome]. */
 suspend fun CalendarRepository.tryDeleteEvent(

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/EventActionsViewModel.kt

@@ -6,7 +6,6 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventDetail
@@ -15,16 +14,16 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.atOccurrence
 import de.jeanlucmakiola.calendula.domain.toDuplicateForm
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import kotlinx.datetime.TimeZone
@@ -50,9 +49,8 @@ class EventActionsViewModel @Inject constructor(
         .map { list -> list.associateBy { it.id } }
         .catch { emit(emptyMap()) }
         .flowOn(io)
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = emptyMap(),
         )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/EventDrag.kt

@@ -212,11 +212,21 @@ private fun rememberPickUpSurface(
         }
 }
 
-/** A lift on pickup, then a tick every time the drop target snaps to a new slot. */
+/**
+ * A lift on pickup, a tick every time the drop target snaps to a new slot, and a
+ * confirm each time [drops] counts a real drop.
+ */
 @Composable
-fun DragSnapHaptics(slot: Any?) {
+fun DragSnapHaptics(slot: Any?, drops: Int) {
     val haptics = LocalHapticFeedback.current
     val previous = remember { arrayOfNulls<Any>(1) }
+    val dropsSeen = remember { intArrayOf(drops) }
+    LaunchedEffect(drops) {
+        if (drops != dropsSeen[0]) {
+            dropsSeen[0] = drops
+            haptics.performHapticFeedback(HapticFeedbackType.Confirm)
+        }
+    }
     LaunchedEffect(slot) {
         val had = previous[0]
         previous[0] = slot

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/EventSelectionHost.kt

@@ -9,7 +9,6 @@ import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.EventForm

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/PageStateCache.kt

@@ -1,10 +1,10 @@
 package de.jeanlucmakiola.calendula.ui.common
 
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.plus
@@ -45,7 +45,7 @@ class PageStateCache<K, S>(
         return entries.getOrPut(key) {
             val job = SupervisorJob(scope.coroutineContext[Job])
             Entry(
-                state = load(key).stateIn(scope + job, SharingStarted.WhileSubscribed(5_000L), initial),
+                state = load(key).stateWhileSubscribed(scope + job, initial),
                 job = job,
             )
         }.state

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/Picker.kt

@@ -1,14 +1,8 @@
 package de.jeanlucmakiola.calendula.ui.common
 
-import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material.icons.Icons
 import androidx.compose.material3.Checkbox
-import androidx.compose.material3.Icon
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
@@ -22,17 +16,16 @@ import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.floret.components.CustomAmountEditor
+import de.jeanlucmakiola.floret.components.CustomExpandRow
 import de.jeanlucmakiola.floret.components.FullScreenPicker
-import de.jeanlucmakiola.floret.components.GroupedListInset
+import de.jeanlucmakiola.floret.components.GroupedHint
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.Position
-import de.jeanlucmakiola.floret.components.SelectedCheck
 import de.jeanlucmakiola.floret.components.positionOf
-import de.jeanlucmakiola.floret.identity.collapseExit
-import de.jeanlucmakiola.floret.identity.expandEnter
 import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.floret.reminders.ReminderOverride
 import de.jeanlucmakiola.floret.reminders.ReminderUnit
+import de.jeanlucmakiola.floret.reminders.minutesOrEmpty
 import de.jeanlucmakiola.floret.reminders.reminderOverrideForMinutes
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.agendaRangeWindowSummary
@@ -90,7 +83,7 @@ fun ReminderDefaultPicker(
     }
     val inherits = current is ReminderOverride.Inherit
     val isNone = current is ReminderOverride.None
-    val selectedMinutes = (current as? ReminderOverride.Minutes)?.minutes.orEmpty()
+    val selectedMinutes = current.minutesOrEmpty()
     // Custom (non-preset) lead times seen this session, so unchecking one keeps
     // its row (unchecked) until the picker closes instead of vanishing mid-tap,
     // which would strand a hand-entered value with no way to re-check it.
@@ -121,24 +114,14 @@ fun ReminderDefaultPicker(
             GroupedRow(
                 title = stringResource(R.string.reminder_use_default),
                 position = Position.Top,
-                selected = inherits,
-                trailing = if (inherits) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
+                checked = inherits,
                 onClick = { apply(ReminderOverride.Inherit) },
             )
         }
         GroupedRow(
             title = stringResource(R.string.reminder_none),
             position = if (allowInherit) Position.Bottom else Position.Alone,
-            selected = isNone,
-            trailing = if (isNone) {
-                { SelectedCheck() }
-            } else {
-                null
-            },
+            checked = isNone,
             onClick = { apply(ReminderOverride.None) },
         )
         Spacer(Modifier.height(24.dp))
@@ -154,17 +137,11 @@ fun ReminderDefaultPicker(
                 onClick = { toggle(minute) },
             )
         }
-        // When expanded, the Custom row connects downward into the editor card
-        // so the two read as one grouped container (the per-calendar pattern).
-        GroupedRow(
+        CustomExpandRow(
             title = stringResource(R.string.event_edit_reminder_custom),
-            position = if (customExpanded) Position.Top else positionOf(rows.size, rowCount),
-            onClick = { customExpanded = !customExpanded },
-        )
-        AnimatedVisibility(
-            visible = customExpanded,
-            enter = expandEnter(),
-            exit = collapseExit(),
+            position = positionOf(rows.size, rowCount),
+            expanded = customExpanded,
+            onExpandedChange = { customExpanded = it },
         ) {
             CustomReminderEditor(
                 amountText = amountText,
@@ -212,19 +189,6 @@ private fun CustomReminderEditor(
     )
 }
 
-/** A short explanatory paragraph shown under a picker's title, above the rows,
- *  on the same left margin as the rows themselves. */
-@Composable
-internal fun PickerDescription(text: String) {
-    Text(
-        text = text,
-        style = MaterialTheme.typography.bodyMedium,
-        color = MaterialTheme.colorScheme.onSurfaceVariant,
-        modifier = Modifier.padding(horizontal = GroupedListInset, vertical = 8.dp),
-    )
-}
-
-
 /**
  * Agenda-range picker, full-screen. Two grouped lists — the calendar-aligned
  * options (today / this week / this month) and the rolling windows (next 7 / 30
@@ -265,17 +229,11 @@ fun AgendaRangePicker(
     }
 
     val rangeRow: @Composable (AgendaRange, Position) -> Unit = { option, position ->
-        val isSelected = option == selected
         GroupedRow(
             title = agendaRangeLabel(option),
             summary = windowSummary(option),
             position = position,
-            selected = isSelected,
-            trailing = if (isSelected) {
-                { SelectedCheck() }
-            } else {
-                null
-            },
+            checked = option == selected,
             onClick = {
                 onSelect(option)
                 onDismiss()
@@ -284,7 +242,7 @@ fun AgendaRangePicker(
     }
 
     FullScreenPicker(title = title, onDismiss = onDismiss) {
-        PickerDescription(description)
+        GroupedHint(description, verticalPadding = 8.dp)
 
         // Calendar-aligned windows.
         calendarAligned.forEachIndexed { index, option ->
@@ -297,7 +255,7 @@ fun AgendaRangePicker(
         rolling.forEachIndexed { index, option ->
             rangeRow(option, positionOf(index, rollingRowCount))
         }
-        GroupedRow(
+        CustomExpandRow(
             title = if (customSelected) {
                 agendaRangeLabel(selected)
             } else {
@@ -306,19 +264,10 @@ fun AgendaRangePicker(
             // An unset custom window has no day count yet, so the row stays
             // single-line until it does.
             summary = if (customSelected) windowSummary(selected) else null,
-            position = if (customExpanded) Position.Top else positionOf(rolling.size, rollingRowCount),
-            selected = customSelected,
-            trailing = if (customSelected) {
-                { SelectedCheck() }
-            } else {
-                null
-            },
-            onClick = { customExpanded = !customExpanded },
-        )
-        AnimatedVisibility(
-            visible = customExpanded,
-            enter = expandEnter(),
-            exit = collapseExit(),
+            position = positionOf(rolling.size, rollingRowCount),
+            expanded = customExpanded,
+            onExpandedChange = { customExpanded = it },
+            checked = customSelected,
         ) {
             CustomDaysEditor(
                 amountText = amountText,
@@ -396,17 +345,12 @@ fun DurationPicker(
     }
 
     FullScreenPicker(title = title, onDismiss = onDismiss, predictiveBack = true) {
-        if (description != null) PickerDescription(description)
+        if (description != null) GroupedHint(description, verticalPadding = 8.dp)
         if (inheritLabel != null) {
             GroupedRow(
                 title = inheritLabel,
                 position = Position.Alone,
-                selected = inherits,
-                trailing = if (inherits) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
+                checked = inherits,
                 onClick = {
                     onSelect(null)
                     onDismiss()
@@ -415,39 +359,22 @@ fun DurationPicker(
             Spacer(Modifier.height(24.dp))
         }
         presets.forEachIndexed { index, minute ->
-            val isSelected = minute == selected
             GroupedRow(
                 title = label(minute),
                 position = positionOf(index, rowCount),
-                selected = isSelected,
-                trailing = if (isSelected) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
+                checked = minute == selected,
                 onClick = {
                     onSelect(minute)
                     onDismiss()
                 },
             )
         }
-        // The Custom row connects downward into the editor card when expanded, so
-        // the two read as one grouped container (the shared custom-expand pattern).
-        GroupedRow(
+        CustomExpandRow(
             title = custom?.let { label(it) } ?: stringResource(R.string.event_edit_reminder_custom),
-            position = if (customExpanded) Position.Top else positionOf(presets.size, rowCount),
-            selected = custom != null,
-            trailing = if (custom != null) {
-                { SelectedCheck() }
-            } else {
-                null
-            },
-            onClick = { customExpanded = !customExpanded },
-        )
-        AnimatedVisibility(
-            visible = customExpanded,
-            enter = expandEnter(),
-            exit = collapseExit(),
+            position = positionOf(presets.size, rowCount),
+            expanded = customExpanded,
+            onExpandedChange = { customExpanded = it },
+            checked = custom != null,
         ) {
             CustomDurationEditor(
                 amountText = amountText,

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/RecurrenceText.kt

@@ -10,6 +10,8 @@ import androidx.compose.ui.text.font.FontStyle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.SimpleRecurrence
 import de.jeanlucmakiola.calendula.domain.occurrencesSpanYears
+import de.jeanlucmakiola.calendula.domain.rruleParts
+import de.jeanlucmakiola.calendula.domain.ics.parseBasicDate
 import de.jeanlucmakiola.calendula.domain.upcomingOccurrences
 import de.jeanlucmakiola.floret.locale.localizedDateFormatter
 import kotlinx.datetime.toJavaLocalDate
@@ -32,10 +34,7 @@ import java.util.Locale
  */
 @Composable
 fun recurrenceText(rrule: String, locale: Locale): AnnotatedString {
-    val parts = rrule.removePrefix("RRULE:").split(';').mapNotNull { token ->
-        val eq = token.indexOf('=')
-        if (eq <= 0) null else token.substring(0, eq).uppercase() to token.substring(eq + 1)
-    }.toMap()
+    val parts = rruleParts(rrule).mapNotNull { part -> part.key?.let { it to part.value } }.toMap()
 
     val freq = parts["FREQ"]?.uppercase()
     val interval = parts["INTERVAL"]?.toIntOrNull() ?: 1
@@ -171,12 +170,5 @@ internal fun untilLocalDate(raw: String, zone: ZoneId = ZoneId.systemDefault()):
             .atOffset(ZoneOffset.UTC)
             .atZoneSameInstant(zone)
             .toLocalDate()
-    }.recoverCatching {
-        val digits = value.takeWhile { it.isDigit() }
-        LocalDate.of(
-            digits.substring(0, 4).toInt(),
-            digits.substring(4, 6).toInt(),
-            digits.substring(6, 8).toInt(),
-        )
-    }.getOrNull()
+    }.getOrNull() ?: parseBasicDate(value.takeWhile { it.isDigit() })?.toJavaLocalDate()
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/RescheduleViewModel.kt

@@ -6,7 +6,6 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.time.ZoneSource
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventFormProblem
@@ -23,22 +22,21 @@ import de.jeanlucmakiola.calendula.domain.resolvedZone
 import de.jeanlucmakiola.calendula.domain.shiftedByDays
 import de.jeanlucmakiola.calendula.domain.shiftedTo
 import de.jeanlucmakiola.calendula.domain.toEditForm
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.map
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.atStartOfDayIn
 import kotlinx.datetime.plus
-import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
 import kotlin.coroutines.cancellation.CancellationException
 import kotlin.time.Instant
@@ -189,9 +187,8 @@ class RescheduleViewModel @Inject constructor(
         .map { calendars -> calendars.filter { it.allowsEventMove }.map { it.id }.toSet() }
         .catch { emit(emptySet<Long>()) }
         .flowOn(io)
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = emptySet(),
         )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/SelectionTopBar.kt

@@ -11,6 +11,8 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.style.TextOverflow
@@ -30,10 +32,13 @@ import kotlin.time.toJavaInstant
 @Composable
 fun SelectionTopBar(selection: EventSelection) {
     val event = selection.event
+    // Follows a move or resize, so the times stay readable under the finger.
+    val preview by remember(selection) { derivedStateOf { selection.preview() } }
+    val shown = preview ?: event
     val use24Hour = LocalUse24HourFormat.current
     val locale = currentLocale()
-    val whenText = remember(event.start, event.end, use24Hour, locale) {
-        formatSelectionWhen(event, use24Hour, locale)
+    val whenText = remember(shown.start, shown.end, use24Hour, locale) {
+        formatSelectionWhen(shown, use24Hour, locale)
     }
     TopAppBar(
         navigationIcon = {

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TimeFormat.kt

@@ -9,6 +9,7 @@ import kotlin.time.Instant
 import kotlin.time.toJavaInstant
 import java.time.format.DateTimeFormatter
 import java.util.Locale
+import kotlinx.datetime.toLocalDateTime
 
 /**
  * The resolved clock convention for the whole UI: `true` = 24-hour ("14:00"),
@@ -37,6 +38,12 @@ fun formatTimeOfDay(hour: Int, minute: Int, is24Hour: Boolean, locale: Locale):
     LocalTime.of(hour.coerceIn(0, 23), minute.coerceIn(0, 59))
         .format(timeOfDayFormatter(is24Hour, locale))
 
+/** [instant]'s wall-clock time in [zone], as [formatTimeOfDay] renders it. */
+fun formatTimeOfDay(instant: Instant, zone: TimeZone, is24Hour: Boolean, locale: Locale): String {
+    val time = instant.toLocalDateTime(zone).time
+    return formatTimeOfDay(time.hour, time.minute, is24Hour, locale)
+}
+
 /**
  * Format minutes-from-midnight (0..1440) as a time label. The end-of-day value
  * 1440 renders as "24:00" in 24h (its established reading) and as midnight

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TimeZonePicker.kt

@@ -1,6 +1,5 @@
 package de.jeanlucmakiola.calendula.ui.common
 
-import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
@@ -39,11 +38,10 @@ import de.jeanlucmakiola.calendula.domain.timeZoneOptionOf
 import de.jeanlucmakiola.calendula.domain.timeZoneOptions
 import de.jeanlucmakiola.calendula.domain.zoneDescriptor
 import de.jeanlucmakiola.floret.components.FullScreenPicker
-import de.jeanlucmakiola.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.GroupedSectionHeader
 import de.jeanlucmakiola.floret.components.InlineTextField
 import de.jeanlucmakiola.floret.components.Position
-import de.jeanlucmakiola.floret.components.SelectedCheck
 import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.floret.locale.currentLocale
 import kotlinx.coroutines.Dispatchers
@@ -118,19 +116,14 @@ fun TimeZonePickerDialog(
                         title = stringResource(R.string.event_edit_timezone_device),
                         summary = deviceSummary,
                         position = Position.Alone,
-                        selected = selected == null,
+                        checked = selected == null,
                         leading = { Icon(Icons.Default.Public, contentDescription = null) },
-                        trailing = if (selected == null) {
-                            { SelectedCheck() }
-                        } else {
-                            null
-                        },
                         onClick = { choose(null) },
                     )
                 }
                 if (recentZones.isNotEmpty()) {
                     item(key = "recent_header") {
-                        SectionHeader(stringResource(R.string.event_edit_timezone_recent))
+                        GroupedSectionHeader(stringResource(R.string.event_edit_timezone_recent))
                     }
                     itemsIndexed(
                         items = recentZones,
@@ -145,7 +138,7 @@ fun TimeZonePickerDialog(
                     }
                 }
                 item(key = "all_header") {
-                    SectionHeader(stringResource(R.string.event_edit_timezone_all))
+                    GroupedSectionHeader(stringResource(R.string.event_edit_timezone_all))
                 }
             }
 
@@ -234,23 +227,6 @@ private fun SearchField(
     }
 }
 
-/** A small primary-coloured group label, matching the settings screens. */
-@Composable
-private fun SectionHeader(text: String) {
-    Text(
-        text = text,
-        style = MaterialTheme.typography.labelLarge,
-        color = MaterialTheme.colorScheme.primary,
-        modifier = Modifier.padding(
-            start = GroupedListInset,
-            end = GroupedListInset,
-            top = 16.dp,
-            bottom = 4.dp,
-        ),
-    )
-}
-
-
 @Composable
 private fun ZoneRow(
     zone: TimeZoneOption,
@@ -262,12 +238,7 @@ private fun ZoneRow(
         title = zone.label,
         summary = zoneDescriptor(zone),
         position = position,
-        selected = selected,
-        trailing = if (selected) {
-            { SelectedCheck() }
-        } else {
-            null
-        },
+        checked = selected,
         onClick = onClick,
     )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TimelineDrag.kt

@@ -5,7 +5,6 @@ import androidx.compose.animation.core.Animatable
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.ScrollState
 import androidx.compose.foundation.MutatePriority
-import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
@@ -19,8 +18,10 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.Stable
+import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateListOf
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -389,17 +390,20 @@ internal fun resizedSpan(
         }
         if (wrongWay) return startMin to endMin
     }
-    val snapped = (edgeMin / DRAG_SNAP_MINUTES).roundToInt() * DRAG_SNAP_MINUTES
+    val snapped = snapToSlot(edgeMin)
     return when (edge) {
         ResizeEdge.Top -> minOf(snapped, endMin - DRAG_SNAP_MINUTES) to endMin
         ResizeEdge.Bottom -> startMin to maxOf(snapped, startMin + DRAG_SNAP_MINUTES)
     }
 }
 
+/** [minutes] rounded to the nearest [DRAG_SNAP_MINUTES] slot. */
+internal fun snapToSlot(minutes: Float): Int = (minutes / DRAG_SNAP_MINUTES).roundToInt() * DRAG_SNAP_MINUTES
+
 /** [minutes] snapped, kept at [held] until three quarters of a step away. */
 internal fun stickySnap(minutes: Float, held: Int?): Int {
     if (held != null && kotlin.math.abs(minutes - held) < DRAG_SNAP_MINUTES * 0.75f) return held
-    return (minutes / DRAG_SNAP_MINUTES).roundToInt() * DRAG_SNAP_MINUTES
+    return snapToSlot(minutes)
 }
 
 /** How far past its column's side the finger has to go before a resize changes day. */
@@ -467,6 +471,10 @@ class TimelineDragController {
     var settling: TimelineDrag? by mutableStateOf(null)
         private set
 
+    /** How many real drops this controller has handed back. */
+    var drops by mutableIntStateOf(0)
+        private set
+
     /**
      * Which block is lifted, and whether anything is. Separate snapshot state
      * from [drag], which changes every frame, so blocks that only need "am I the
@@ -618,25 +626,8 @@ class TimelineDragController {
      */
     private var originSlot: Triple<LocalDate, Int, Int>? = null
 
-    /** The edge a resize is dragging, or null for a plain drag (#141). */
-    private var resizeEdge: ResizeEdge? = null
-
-    /** The day the resized event starts on; its edges are minutes from that midnight. */
-    private var resizeDay: LocalDate? = null
-    private var resizeStartMin = 0
-    private var resizeEndMin = 0
-
-    /** How far the finger sits past the edge it grabbed, so the edge doesn't jump to it. */
-    private var resizeGrabMin = 0f
-
-    /** The column the resized edge is in, held until the finger is well into another. */
-    private var resizeColumn: Int? = null
-
-    /** The slot the resized edge sits on, held against a finger trembling between two. */
-    private var resizeSlot: Int? = null
-
-    /** The day, counted from the event's start day, the finger is resizing in. */
-    private var resizeEdgeDay = 0
+    /** The resize in progress, or null for a plain drag (#141). */
+    private var resize: ResizeSession? = null
 
     fun begin(
         block: TimedBlock,
@@ -683,10 +674,7 @@ class TimelineDragController {
     }
 
     fun cancel() {
-        resizeEdge = null
-        resizeDay = null
-        resizeColumn = null
-        resizeSlot = null
+        resize = null
         source = null
         clipOffsetMin = 0
         dragZone = null
@@ -761,6 +749,12 @@ class TimelineDragController {
         if (landed == null || landed.slot == origin) return null
         // A draft dropped on a day off screen would vanish, so it stays where it was (#153).
         if (landed.edgeOnly && landed.event.isDraft) return null
+        settle(landed)
+        return TimelineDrop(landed.event, landed.date, landed.startMin, clipOffset)
+    }
+
+    /** Keep [landed]'s copy on the target as [settling] until [release]; [end] is a resize's. */
+    private fun settle(landed: TimelineDrag, end: Instant? = null) {
         settlingSelected = selection?.event?.instanceId == landed.event.instanceId
         // An edge piece is a hint for the finger, not a preview of the landing
         // slot: the event belongs to a day this timeline has no column for, so
@@ -770,7 +764,8 @@ class TimelineDragController {
         liftedInstanceId = landed.event.instanceId
         settledOrigin = landed.event.eventId to landed.event.start
         settledAbandonedMark = abandonedTicks?.value ?: 0
-        return TimelineDrop(landed.event, landed.date, landed.startMin, clipOffset)
+        settledEnd = end
+        drops++
     }
 
     /**
@@ -785,11 +780,9 @@ class TimelineDragController {
         pointerInRoot: Offset,
     ) {
         val span = wallClockSpan(block.event, zone)
+        val session = ResizeSession(edge, span.day, span.startMin, span.endMin)
         source = block
-        resizeEdge = edge
-        resizeDay = span.day
-        resizeStartMin = span.startMin
-        resizeEndMin = span.endMin
+        resize = session
         clipOffsetMin = 0
         this.titleLines = titleLines
         settling = null
@@ -798,17 +791,36 @@ class TimelineDragController {
         liftedInstanceId = block.event.instanceId
         pointer = pointerInRoot
         // Measured from the edge's own column: the handle overhangs into the next.
-        val edgeDay = if (edge == ResizeEdge.Top) 0 else (resizeEndMin - 1).floorDiv(MINUTES_PER_DAY).coerceAtLeast(0)
+        val edgeDay = if (edge == ResizeEdge.Top) 0 else (session.endMin - 1).floorDiv(MINUTES_PER_DAY).coerceAtLeast(0)
         val edgeIndex = geometry.days.indexOf(span.day.plus(edgeDay, DateTimeUnit.DAY))
-        resizeColumn = edgeIndex.takeIf { it >= 0 }
-            ?.let { if (geometry.isRtl) geometry.days.lastIndex - it else it }
-        resizeGrabMin = (pointerResizeMinutes() ?: 0f) -
-            if (edge == ResizeEdge.Top) resizeStartMin else resizeEndMin
+        session.column = edgeIndex.takeIf { it >= 0 }
+            ?.let { column(it) }
+        session.grabMin = (pointerResizeMinutes(session) ?: 0f) -
+            if (edge == ResizeEdge.Top) session.startMin else session.endMin
         originSlot = null
         recompute()
         originSlot = drag?.slot
     }
 
+    /** The slot the gesture would land on, changing once per snap rather than per frame. */
+    private val landingSlot by derivedStateOf { drag?.slot }
+
+    /**
+     * The dragged event at the times letting go now would give it, worked out as
+     * [finish] and [finishResize] do. Null while it is still on its own slot (#141).
+     */
+    fun preview(zone: TimeZone): EventInstance? {
+        val (date, startMin, spanMin) = landingSlot?.takeIf { it != originSlot } ?: return null
+        val event = source?.event ?: return null
+        val edge = resize?.edge
+        if (edge != null) {
+            val drop = resizedDrop(event, edge, date, startMin, spanMin, zone)
+            return event.copy(start = drop.start, end = drop.end)
+        }
+        val start = TimelineDrop(event, date, startMin, clipOffsetMin).startInstant(zone)
+        return event.copy(start = start, end = start + dragDuration)
+    }
+
     /**
      * End a resize, handing back the event's new span — null when it never
      * resolved or came back to the length it started at. Settles as [finish] does.
@@ -816,16 +828,11 @@ class TimelineDragController {
     fun finishResize(zone: TimeZone): TimelineResizeDrop? {
         val landed = drag
         val origin = originSlot
-        val edge = resizeEdge
+        val edge = resize?.edge
         cancel()
         if (landed == null || landed.slot == origin) return null
         val drop = resizedDrop(landed.event, edge, landed.date, landed.eventStartMin, landed.eventSpanMin, zone)
-        settlingSelected = selection?.event?.instanceId == landed.event.instanceId
-        settling = if (landed.edgeOnly) landed.copy(pieces = emptyList()) else landed
-        liftedInstanceId = landed.event.instanceId
-        settledOrigin = landed.event.eventId to landed.event.start
-        settledAbandonedMark = abandonedTicks?.value ?: 0
-        settledEnd = drop.end
+        settle(landed, end = drop.end)
         return drop
     }
 
@@ -833,36 +840,33 @@ class TimelineDragController {
      * Where the finger is, in minutes from the resized event's start day —
      * past 1440 in a later column, negative in an earlier one.
      */
-    private fun pointerResizeMinutes(): Float? {
+    private fun pointerResizeMinutes(session: ResizeSession): Float? {
         val grid = geometry.grid?.takeIf { it.isAttached } ?: return null
-        val day = resizeDay ?: return null
         val hourPx = geometry.hourPx
         val columnPx = geometry.columnWidthPx
         val days = geometry.days
         if (hourPx <= 0f || columnPx <= 0f || days.isEmpty()) return null
         val origin = grid.positionInRoot()
-        val column = stickyColumn(
+        val held = stickyColumn(
             position = (pointer.x - origin.x) / columnPx,
-            held = resizeColumn,
+            held = session.column,
             lastIndex = days.lastIndex,
         )
-        resizeColumn = column
-        val dayIndex = if (geometry.isRtl) days.lastIndex - column else column
-        val dayOffset = (days[dayIndex].toEpochDays() - day.toEpochDays()).toInt()
-        resizeEdgeDay = dayOffset
+        session.column = held
+        val dayOffset = (days[column(held)].toEpochDays() - session.day.toEpochDays()).toInt()
+        session.edgeDay = dayOffset
         return dayOffset * MINUTES_PER_DAY + (pointer.y - origin.y) / hourPx * 60f
     }
 
-    private fun recomputeResize(edge: ResizeEdge) {
+    private fun recomputeResize(session: ResizeSession) {
         val block = source ?: return
-        val day = resizeDay ?: return
-        val raw = pointerResizeMinutes() ?: return
-        val slot = stickySnap(raw - resizeGrabMin, resizeSlot)
-        resizeSlot = slot
-        val (start, end) = resizedSpan(edge, resizeStartMin, resizeEndMin, slot.toFloat(), resizeEdgeDay)
+        val edge = session.edge
+        val day = session.day
+        val raw = pointerResizeMinutes(session) ?: return
+        val slot = stickySnap(raw - session.grabMin, session.slot)
+        session.slot = slot
+        val (start, end) = resizedSpan(edge, session.startMin, session.endMin, slot.toFloat(), session.edgeDay)
         val days = geometry.days
-        val hourPx = geometry.hourPx
-        val columnPx = geometry.columnWidthPx
         val origin = geometry.grid?.takeIf { it.isAttached }?.positionInRoot() ?: return
         // Which column the start day sits in, possibly off either end of the view.
         val startIndex = (day.toEpochDays() - days.first().toEpochDays()).toInt()
@@ -875,20 +879,7 @@ class TimelineDragController {
             eventStartMin = start,
             eventSpanMin = end - start,
             titleLines = titleLines,
-            pieces = slices.map { slice ->
-                val dayIndex = startIndex + slice.dayOffset
-                val col = if (geometry.isRtl) days.lastIndex - dayIndex else dayIndex
-                val bounds = dragPieceBounds(slice, hourPx, geometry.blockInsetPx)
-                TimelineDragPiece(
-                    topLeftInRoot = Offset(x = origin.x + col * columnPx, y = origin.y + bounds.top),
-                    sizePx = IntSize(
-                        (columnPx - geometry.columnGapPx).roundToInt(),
-                        bounds.height.roundToInt(),
-                    ),
-                    continuesBefore = slice.continuesBefore,
-                    continuesAfter = slice.continuesAfter,
-                )
-            },
+            pieces = pieces(slices, startIndex, origin),
             edgeOnly = slices.isEmpty(),
             markerMin = if (edge == ResizeEdge.Top) {
                 start.mod(MINUTES_PER_DAY)
@@ -933,7 +924,7 @@ class TimelineDragController {
      * no move events while auto-scroll walks the content underneath it.
      */
     fun recompute() {
-        resizeEdge?.let {
+        resize?.let {
             recomputeResize(it)
             return
         }
@@ -946,10 +937,9 @@ class TimelineDragController {
 
         val origin = grid.positionInRoot()
         val rawMinutes = (pointer.y - grab.y - origin.y) / hourPx * 60f
-        val snapped = (rawMinutes / DRAG_SNAP_MINUTES).roundToInt() * DRAG_SNAP_MINUTES
+        val snapped = snapToSlot(rawMinutes)
         val zone = dragZone ?: return
-        val column = ((pointer.x - origin.x) / columnPx).toInt().coerceIn(0, days.lastIndex)
-        val dayIndex = if (geometry.isRtl) days.lastIndex - column else column
+        val dayIndex = column(((pointer.x - origin.x) / columnPx).toInt().coerceIn(0, days.lastIndex))
         val target = days[dayIndex]
         val keep = dragKept
         // Measured where it would land: the drop keeps the real duration, which in
@@ -977,28 +967,34 @@ class TimelineDragController {
             titleLines = titleLines,
             // Bounded to the columns this timeline actually shows: a day it
             // doesn't has no piece to draw. The write is unaffected.
-            pieces = slices
-                .map { slice ->
-                    val day = dayIndex + slice.dayOffset
-                    val col = if (geometry.isRtl) days.lastIndex - day else day
-                    val bounds = dragPieceBounds(slice, hourPx, geometry.blockInsetPx)
-                    TimelineDragPiece(
-                        topLeftInRoot = Offset(
-                            x = origin.x + col * columnPx,
-                            y = origin.y + bounds.top,
-                        ),
-                        sizePx = IntSize(
-                            (columnPx - geometry.columnGapPx).roundToInt(),
-                            bounds.height.roundToInt(),
-                        ),
-                        continuesBefore = slice.continuesBefore,
-                        continuesAfter = slice.continuesAfter,
-                    )
-                },
+            pieces = pieces(slices, dayIndex, origin),
             edgeOnly = onGrid.isEmpty(),
         )
     }
 
+    /** [slices] as floating pieces, the first slice's day being [dayIndex] in the shown days. */
+    private fun pieces(slices: List<DragSlice>, dayIndex: Int, origin: Offset): List<TimelineDragPiece> {
+        val columnPx = geometry.columnWidthPx
+        return slices.map { slice ->
+            val bounds = dragPieceBounds(slice, geometry.hourPx, geometry.blockInsetPx)
+            TimelineDragPiece(
+                topLeftInRoot = Offset(
+                    x = origin.x + column(dayIndex + slice.dayOffset) * columnPx,
+                    y = origin.y + bounds.top,
+                ),
+                sizePx = IntSize(
+                    (columnPx - geometry.columnGapPx).roundToInt(),
+                    bounds.height.roundToInt(),
+                ),
+                continuesBefore = slice.continuesBefore,
+                continuesAfter = slice.continuesAfter,
+            )
+        }
+    }
+
+    /** The on-screen column of a day index, and back: right-to-left lays the days out mirrored. */
+    private fun column(index: Int): Int = if (geometry.isRtl) geometry.days.lastIndex - index else index
+
     /**
      * Hold the scroll for the whole drag and nudge it once per frame while the
      * finger sits near an edge. One `scroll` call, since a loop of
@@ -1031,6 +1027,27 @@ class TimelineDragController {
     }
 }
 
+/** One resize gesture (#141): the edge it drags, and the edges as minutes from [day]'s midnight. */
+private class ResizeSession(
+    val edge: ResizeEdge,
+    /** The day the resized event starts on. */
+    val day: LocalDate,
+    val startMin: Int,
+    val endMin: Int,
+) {
+    /** How far the finger sits past the edge it grabbed, so the edge doesn't jump to it. */
+    var grabMin = 0f
+
+    /** The column the resized edge is in, held until the finger is well into another. */
+    var column: Int? = null
+
+    /** The slot the resized edge sits on, held against a finger trembling between two. */
+    var slot: Int? = null
+
+    /** The day, counted from the event's start day, the finger is resizing in. */
+    var edgeDay = 0
+}
+
 @Composable
 fun rememberTimelineDragController(): TimelineDragController {
     val controller = remember { TimelineDragController() }
@@ -1160,7 +1177,7 @@ fun TimelineDragOverlay(controller: TimelineDragController, modifier: Modifier =
 
     // Both live here rather than beside the controller: they read [drag], which
     // changes every frame, and this composable is the one that is meant to.
-    DragSnapHaptics(controller.drag?.slot)
+    DragSnapHaptics(controller.drag?.slot, controller.drops)
     // Only once the finger has moved: a long press held near an edge must not
     // scroll the drop target out from under a finger that only means to select.
     LaunchedEffect(controller.isDragging && controller.pointerMoved) {

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TimelineHours.kt

@@ -16,8 +16,6 @@ data class TimelineHours(
     val startHour: Int = DEFAULT_START_HOUR,
     val endHour: Int = DEFAULT_END_HOUR,
 ) {
-    val span: Int get() = endHour - startHour
-
     companion object {
         const val DEFAULT_START_HOUR = 7
         const val DEFAULT_END_HOUR = 22

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/ViewPreview.kt

@@ -1,145 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.common
-
-import androidx.compose.animation.Crossfade
-import androidx.compose.animation.core.snap
-import androidx.compose.animation.core.tween
-import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.draw.clipToBounds
-import androidx.compose.ui.graphics.TransformOrigin
-import androidx.compose.ui.graphics.graphicsLayer
-import androidx.compose.ui.input.pointer.PointerEventPass
-import androidx.compose.ui.input.pointer.pointerInput
-import androidx.compose.ui.layout.layout
-import androidx.compose.ui.platform.LocalConfiguration
-import androidx.compose.ui.semantics.clearAndSetSemantics
-import androidx.compose.ui.unit.Constraints
-import androidx.compose.ui.unit.Dp
-import androidx.compose.ui.unit.dp
-import de.jeanlucmakiola.floret.components.GroupedListInset
-import de.jeanlucmakiola.floret.identity.rememberReduceMotion
-import kotlin.math.roundToInt
-
-/**
- * The viewport a view preview pretends to be: a phone's width by the height a
- * calendar view gets under the top bar. Scaling every preview from one fixed
- * height keeps them comparable — each shows the same slice of screen.
- */
-internal val PREVIEW_VIEWPORT_HEIGHT = 440.dp
-
-/**
- * Renders [content] at a full phone viewport and shrinks the finished layout
- * into a box [height] tall, for the settings and onboarding choosers. Callers
- * pass the *real* view composables, so a preview cannot drift from what it
- * depicts.
- *
- * The [layout] below ignores the incoming constraints so the view measures at a
- * phone viewport, and a [graphicsLayer] scale shrinks the result.
- * `Modifier.requiredSize` is the obvious alternative but *centres* content that
- * overflows its constraints, leaving only the bottom-right corner in the clip.
- */
-@Composable
-internal fun ScaledViewPreview(
-    height: Dp,
-    modifier: Modifier = Modifier,
-    content: @Composable () -> Unit,
-) {
-    val screenWidth = LocalConfiguration.current.screenWidthDp.dp
-    val scale = height.value / PREVIEW_VIEWPORT_HEIGHT.value
-
-    Box(
-        modifier = modifier
-            .clipToBounds()
-            .background(MaterialTheme.colorScheme.surface)
-            // A preview is a picture, not a control: swallow touches before the
-            // view's own clickables see them, and give screen readers one label
-            // instead of six weeks of day cells.
-            .pointerInput(Unit) {
-                awaitPointerEventScope {
-                    while (true) {
-                        awaitPointerEvent(PointerEventPass.Initial).changes
-                            .forEach { it.consume() }
-                    }
-                }
-            }
-            .clearAndSetSemantics { }
-            // Measure at a full phone viewport but report the scaled size, so the
-            // node occupies exactly what it draws.
-            .layout { measurable, _ ->
-                val fullWidth = screenWidth.roundToPx()
-                val fullHeight = PREVIEW_VIEWPORT_HEIGHT.roundToPx()
-                val placeable = measurable.measure(Constraints.fixed(fullWidth, fullHeight))
-                layout((fullWidth * scale).roundToInt(), (fullHeight * scale).roundToInt()) {
-                    placeable.place(0, 0)
-                }
-            }
-            .graphicsLayer {
-                scaleX = scale
-                scaleY = scale
-                transformOrigin = TransformOrigin(0f, 0f)
-            },
-    ) {
-        Column(Modifier.fillMaxSize()) { content() }
-    }
-}
-
-/**
- * The stage every preview picker sets its preview on, cross-fading as [selected]
- * changes. A preview draws the app's own surface, so a tonal plate gives it the
- * edge it would otherwise lack on a chooser screen; the plate takes the width
- * and outer radius of the grouped rows underneath so the two read as one stack.
- *
- * Only vertical spacing is the caller's to pass — the horizontal inset is the
- * rows' own, and the alignment is the point.
- */
-@Composable
-internal fun <T> ViewPreviewFrame(
-    selected: T,
-    label: String,
-    modifier: Modifier = Modifier,
-    content: @Composable (T) -> Unit,
-) {
-    val reduceMotion = rememberReduceMotion()
-    Box(
-        modifier = modifier
-            .fillMaxWidth()
-            .padding(horizontal = GroupedListInset)
-            .clip(FRAME_SHAPE)
-            .background(MaterialTheme.colorScheme.surfaceContainerHigh)
-            .padding(FRAME_INSET),
-        contentAlignment = Alignment.Center,
-    ) {
-        Crossfade(
-            targetState = selected,
-            animationSpec = if (reduceMotion) snap() else tween(durationMillis = 250),
-            label = label,
-        ) { shown ->
-            // Each preview renders the real view at phone size and scales it
-            // down, so its own corners are square — the plate rounds them.
-            Box(
-                modifier = Modifier
-                    .clip(PREVIEW_SHAPE)
-                    .background(MaterialTheme.colorScheme.surface)
-                    .clipToBounds(),
-            ) {
-                content(shown)
-            }
-        }
-    }
-}
-
-private val FRAME_INSET = 8.dp
-
-/** The grouped rows' own outer radius, so the stack shares one silhouette. */
-private val FRAME_SHAPE = RoundedCornerShape(22.dp)
-private val PREVIEW_SHAPE = RoundedCornerShape(12.dp)

app/src/main/java/de/jeanlucmakiola/calendula/ui/day/DayPaging.kt

@@ -1,22 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.day
-
-import kotlinx.datetime.DateTimeUnit
-import kotlinx.datetime.LocalDate
-import kotlinx.datetime.daysUntil
-import kotlinx.datetime.plus
-
-/** Pages the day pager spans — a little under four centuries, centred on [PAGE_EPOCH]. */
-internal const val DAY_PAGE_COUNT: Int = 140_000
-
-private const val EPOCH_PAGE = DAY_PAGE_COUNT / 2
-
-/** The day at [EPOCH_PAGE]; any date works, it only has to stay fixed. */
-private val PAGE_EPOCH = LocalDate(2000, 1, 1)
-
-/** The day shown on pager [page]. */
-internal fun dayForPage(page: Int): LocalDate =
-    PAGE_EPOCH.plus(page - EPOCH_PAGE, DateTimeUnit.DAY)
-
-/** The pager page showing [date]. */
-internal fun dayPageFor(date: LocalDate): Int =
-    (EPOCH_PAGE + PAGE_EPOCH.daysUntil(date)).coerceIn(0, DAY_PAGE_COUNT - 1)

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailScreen.kt

@@ -8,7 +8,6 @@ import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.ColumnScope
 import androidx.compose.foundation.layout.ExperimentalLayoutApi
 import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.Row
@@ -17,7 +16,6 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -58,7 +56,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.AnnotatedString
@@ -87,11 +84,13 @@ import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.EventStatus
 import de.jeanlucmakiola.calendula.domain.InlineStyle
-import de.jeanlucmakiola.calendula.domain.Reminder
 import de.jeanlucmakiola.calendula.domain.RichText
 import de.jeanlucmakiola.calendula.domain.TimeZoneOption
 import de.jeanlucmakiola.calendula.domain.timeZoneOptionOf
 import de.jeanlucmakiola.calendula.domain.zoneDescriptor
+import de.jeanlucmakiola.calendula.domain.zoneOrNull
+import de.jeanlucmakiola.calendula.ui.common.orUnnamed
+import de.jeanlucmakiola.floret.components.IconInfoCard
 import de.jeanlucmakiola.floret.identity.LocalFloretDarkTheme
 import de.jeanlucmakiola.floret.identity.predictiveBack
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
@@ -104,7 +103,6 @@ import de.jeanlucmakiola.calendula.ui.common.rememberFieldCopier
 import de.jeanlucmakiola.calendula.ui.common.icuTimeZoneRegion
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.eventAccent
-import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
@@ -304,7 +302,7 @@ private fun EventDetailContent(
     val detail = state.detail
     val instance = detail.instance
     val dark = LocalFloretDarkTheme.current
-    val locale = currentDetailLocale()
+    val locale = currentLocale()
     val accent = eventAccent(instance.color, dark, LocalSoftenColors.current)
 
     Column(
@@ -385,7 +383,7 @@ private fun EventDetailContent(
 
         // "When" — date/all-day plus the time range.
         val (whenPrimary, whenSecondary) = rememberWhen(instance, TimeZone.currentSystemDefault(), locale)
-        DetailCard(icon = Icons.Default.Schedule, iconContentDescription = null) {
+        IconInfoCard(icon = Icons.Default.Schedule, iconContentDescription = null) {
             Text(text = whenPrimary, style = MaterialTheme.typography.titleMedium)
             if (whenSecondary != null) {
                 Spacer(Modifier.height(2.dp))
@@ -410,7 +408,7 @@ private fun EventDetailContent(
         }
         foreignZone?.let { zoneOption ->
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.Default.Public,
                 iconContentDescription = stringResource(R.string.event_detail_timezone),
             ) {
@@ -423,7 +421,7 @@ private fun EventDetailContent(
                 // — which a cross-zone event easily does — carries the whole span
                 // in the primary instead, so fall back to it. If the zone can't be
                 // read back at all, drop to just the abbreviation + offset.
-                val originalTime = runCatching { TimeZone.of(zoneOption.id) }.getOrNull()
+                val originalTime = zoneOrNull(zoneOption.id)
                     ?.let { rememberWhen(instance, it, locale) }
                     ?.let { (primary, secondary) -> secondary ?: primary }
                 Spacer(Modifier.height(2.dp))
@@ -442,13 +440,13 @@ private fun EventDetailContent(
         // Calendar — icon tinted in the calendar colour conveys identity, so no
         // separate colour dot is needed.
         Spacer(Modifier.height(gap))
-        DetailCard(
+        IconInfoCard(
             icon = Icons.Default.CalendarMonth,
             iconTint = accent,
             iconContentDescription = stringResource(R.string.event_detail_calendar),
         ) {
             Text(
-                text = state.calendarName?.ifBlank { stringResource(R.string.calendar_unnamed) }
+                text = state.calendarName?.orUnnamed()
                     ?: stringResource(R.string.event_detail_calendar_unknown),
                 style = MaterialTheme.typography.titleMedium,
             )
@@ -460,7 +458,7 @@ private fun EventDetailContent(
             val context = LocalContext.current
             val locationLabel = stringResource(R.string.event_detail_location)
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.Default.Place,
                 iconContentDescription = locationLabel,
             ) {
@@ -487,7 +485,7 @@ private fun EventDetailContent(
         state.description?.let { description ->
             val descriptionLabel = stringResource(R.string.event_detail_description)
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.AutoMirrored.Filled.Notes,
                 iconContentDescription = descriptionLabel,
                 // The gesture sits on the card so the icon and padding answer
@@ -506,7 +504,7 @@ private fun EventDetailContent(
         // each attendee with their role and reply.
         detail.attendees.takeIf { it.isNotEmpty() }?.let { attendees ->
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.Default.People,
                 iconContentDescription = stringResource(R.string.event_detail_attendees),
             ) {
@@ -528,7 +526,7 @@ private fun EventDetailContent(
         // Reminders (conditional) — list each lead time before the event.
         detail.reminders.takeIf { it.isNotEmpty() }?.let { reminders ->
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.Default.Notifications,
                 iconContentDescription = stringResource(R.string.event_detail_reminders),
             ) {
@@ -537,7 +535,7 @@ private fun EventDetailContent(
                     .sortedBy { it.minutes }
                     .forEach { reminder ->
                         Text(
-                            text = reminderLeadText(reminder),
+                            text = reminderLeadTimeLabel(reminder.minutes),
                             style = MaterialTheme.typography.titleMedium,
                             modifier = Modifier.padding(vertical = 2.dp),
                         )
@@ -548,7 +546,7 @@ private fun EventDetailContent(
         // Recurrence (conditional) — humanised from the RRULE.
         detail.rrule?.takeIf { it.isNotBlank() }?.let { rrule ->
             Spacer(Modifier.height(gap))
-            DetailCard(
+            IconInfoCard(
                 icon = Icons.Default.Repeat,
                 iconContentDescription = stringResource(R.string.event_detail_recurrence),
             ) {
@@ -561,36 +559,6 @@ private fun EventDetailContent(
     }
 }
 
-/** One info card: tonal container, leading icon in the gutter, value to the right. */
-@Composable
-private fun DetailCard(
-    icon: ImageVector,
-    iconContentDescription: String?,
-    modifier: Modifier = Modifier,
-    iconTint: Color = MaterialTheme.colorScheme.onSurfaceVariant,
-    content: @Composable ColumnScope.() -> Unit,
-) {
-    Surface(
-        color = MaterialTheme.colorScheme.surfaceContainerHigh,
-        shape = RoundedCornerShape(16.dp),
-        modifier = modifier.fillMaxWidth(),
-    ) {
-        Row(
-            modifier = Modifier.padding(16.dp),
-            verticalAlignment = Alignment.CenterVertically,
-        ) {
-            Icon(
-                imageVector = icon,
-                contentDescription = iconContentDescription,
-                tint = iconTint,
-                modifier = Modifier.size(24.dp),
-            )
-            Spacer(Modifier.width(16.dp))
-            Column(modifier = Modifier.weight(1f), content = content)
-        }
-    }
-}
-
 @Composable
 private fun AttendeeRow(attendee: Attendee) {
     Row(
@@ -714,11 +682,6 @@ private fun SkeletonBar(widthFraction: Float, height: Dp) {
 
 // --- helpers -------------------------------------------------------------
 
-// Observable locale read (shared helper) — avoids NonObservableLocale /
-// LocalContextConfigurationRead lint by going through LocalConfiguration.
-@Composable
-private fun currentDetailLocale(): Locale = currentLocale()
-
 private fun attendeeStatusLabel(status: AttendeeStatus): Int = when (status) {
     AttendeeStatus.Accepted -> R.string.event_attendee_accepted
     AttendeeStatus.Declined -> R.string.event_attendee_declined
@@ -738,10 +701,6 @@ private fun attendeeRoleLabel(attendee: Attendee): Int? = when {
     else -> null
 }
 
-/** Humanise a reminder's lead time, e.g. "10 minutes before" / "At time of event". */
-@Composable
-private fun reminderLeadText(reminder: Reminder): String = reminderLeadTimeLabel(reminder.minutes)
-
 /**
  * [tz] resolved as a [TimeZoneOption], but only when the event is timed and
  * pinned to a zone different from the device's — the cases where showing it

app/src/main/java/de/jeanlucmakiola/calendula/ui/detail/EventDetailViewModel.kt

@@ -6,7 +6,6 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.domain.EventForm
 import de.jeanlucmakiola.calendula.domain.FailureReason
@@ -17,11 +16,12 @@ import de.jeanlucmakiola.calendula.domain.toDuplicateForm
 import de.jeanlucmakiola.calendula.ui.common.DeleteOutcome
 import de.jeanlucmakiola.calendula.ui.common.tryDeleteEvent
 import de.jeanlucmakiola.calendula.ui.common.stageEventShare
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
@@ -30,7 +30,6 @@ import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlinx.datetime.TimeZone
 import kotlin.coroutines.cancellation.CancellationException
@@ -76,9 +75,8 @@ class EventDetailViewModel @Inject constructor(
                 }
             }
             .flowOn(io)
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = EventDetailUiState.Loading,
             )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/edit/EventEditViewModel.kt

@@ -7,7 +7,6 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.NoSuchEventException
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsExporter
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
@@ -23,7 +22,6 @@ import de.jeanlucmakiola.calendula.domain.EventAttendee
 import de.jeanlucmakiola.calendula.domain.EventColorOption
 import de.jeanlucmakiola.calendula.domain.EventDetail
 import de.jeanlucmakiola.calendula.domain.EventForm
-import de.jeanlucmakiola.calendula.domain.endInstant
 import de.jeanlucmakiola.calendula.domain.nextFullHour
 import de.jeanlucmakiola.calendula.domain.toFormTime
 import de.jeanlucmakiola.calendula.domain.resolvedZone
@@ -43,6 +41,8 @@ import de.jeanlucmakiola.calendula.ui.detail.EventDetailViewModel.Companion.NO_O
 import de.jeanlucmakiola.calendula.ui.common.DeleteOutcome
 import de.jeanlucmakiola.calendula.ui.common.tryDeleteEvent
 import de.jeanlucmakiola.calendula.ui.common.stageEventShare
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
@@ -339,9 +339,8 @@ class EventEditViewModel @Inject constructor(
             allowColorOnUnsupportedCalendars = external.allowColorOnUnsupported,
         )
     }
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = null,
         )
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/CalendarFilterList.kt

@@ -20,8 +20,10 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import de.jeanlucmakiola.calendula.ui.common.CalendarAccountGroup
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
-import de.jeanlucmakiola.calendula.ui.common.sourceAppName
+import de.jeanlucmakiola.calendula.ui.common.accountGroupTitle
+import de.jeanlucmakiola.calendula.ui.common.orUnnamed
 import de.jeanlucmakiola.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.GroupedRow
 import de.jeanlucmakiola.floret.components.positionOf
@@ -43,6 +45,7 @@ fun CalendarFilterList(
         is FilterUiState.Failure -> FilterMessage(s.reason, modifier)
         is FilterUiState.Success -> FilterList(
             groups = s.groups,
+            hidden = s.hidden,
             onSetVisible = viewModel::setVisible,
             modifier = modifier,
         )
@@ -56,23 +59,15 @@ fun CalendarFilterList(
  */
 @Composable
 private fun FilterList(
-    groups: List<AccountGroup>,
+    groups: List<CalendarAccountGroup>,
+    hidden: Set<Long>,
     onSetVisible: (Long, Boolean) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     Column(modifier = modifier.fillMaxWidth()) {
         groups.forEach { group ->
-            val account = group.account.ifBlank { stringResource(R.string.calendar_unnamed) }
             Text(
-                text = if (group.ambiguous) {
-                    stringResource(
-                        R.string.calendars_account_from_source,
-                        account,
-                        sourceAppName(group.accountType),
-                    )
-                } else {
-                    account
-                },
+                text = accountGroupTitle(group),
                 style = MaterialTheme.typography.labelMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
                 modifier = Modifier.padding(
@@ -83,18 +78,19 @@ private fun FilterList(
                 ),
             )
             group.calendars.forEachIndexed { index, cal ->
+                val visible = cal.id !in hidden
                 GroupedRow(
-                    title = cal.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
+                    title = cal.displayName.orUnnamed(),
                     position = positionOf(index, group.calendars.size),
                     minHeight = 56.dp,
                     leading = { CalendarColorChip(cal.color) },
                     trailing = {
                         Checkbox(
-                            checked = cal.visible,
+                            checked = visible,
                             onCheckedChange = { onSetVisible(cal.id, it) },
                         )
                     },
-                    onClick = { onSetVisible(cal.id, !cal.visible) },
+                    onClick = { onSetVisible(cal.id, !visible) },
                 )
             }
         }

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/FilterUiState.kt

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.filter
 
 import de.jeanlucmakiola.calendula.domain.FailureReason
+import de.jeanlucmakiola.calendula.ui.common.CalendarAccountGroup
 
 /**
  * State for the calendar-filter sheet (M3). The user toggles per-calendar
@@ -10,26 +11,9 @@ import de.jeanlucmakiola.calendula.domain.FailureReason
 sealed interface FilterUiState {
     data object Loading : FilterUiState
     data class Failure(val reason: FailureReason) : FilterUiState
-    data class Success(val groups: List<AccountGroup>) : FilterUiState
+    /** A calendar shows when its id is *not* in [hidden]. */
+    data class Success(
+        val groups: List<CalendarAccountGroup>,
+        val hidden: Set<Long>,
+    ) : FilterUiState
 }
-
-/**
- * Calendars grouped under the account that owns them (Nextcloud / Local / …).
- *
- * [accountType] and [ambiguous] carry what the header needs to tell two
- * same-named accounts from different apps apart (#77); the label itself is
- * built in the UI layer, which is where the source app's name can be looked up.
- */
-data class AccountGroup(
-    val account: String,
-    val accountType: String,
-    val ambiguous: Boolean,
-    val calendars: List<CalendarRow>,
-)
-
-data class CalendarRow(
-    val id: Long,
-    val displayName: String,
-    val color: Int,
-    val visible: Boolean,
-)

app/src/main/java/de/jeanlucmakiola/calendula/ui/filter/FilterViewModel.kt

@@ -4,20 +4,18 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
-import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.FailureReason
 import de.jeanlucmakiola.calendula.domain.calendarListFailure
 import de.jeanlucmakiola.calendula.ui.common.groupByAccount
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flowOn
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import javax.inject.Inject
 
@@ -40,14 +38,13 @@ class FilterViewModel @Inject constructor(
             if (failure != null) {
                 FilterUiState.Failure(failure)
             } else {
-                FilterUiState.Success(groupCalendarsForFilter(enabled, hidden))
+                FilterUiState.Success(enabled.groupByAccount(), hidden)
             }
         }
             .catch { emit(FilterUiState.Failure(FailureReason.ProviderUnavailable)) }
             .flowOn(io)
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = FilterUiState.Loading,
             )
 
@@ -61,28 +58,3 @@ class FilterViewModel @Inject constructor(
     }
 }
 
-/**
- * Group calendars under their owning account — by name *and* type, so two
- * accounts that merely share a name stay apart (#77) — preserving the
- * provider's order within each group and ordering groups by first appearance.
- * A calendar is "visible" when its id is *not* in [hidden].
- */
-internal fun groupCalendarsForFilter(
-    calendars: List<CalendarSource>,
-    hidden: Set<Long>,
-): List<AccountGroup> =
-    calendars.groupByAccount().map { group ->
-        AccountGroup(
-            account = group.label,
-            accountType = group.accountType,
-            ambiguous = group.ambiguous,
-            calendars = group.calendars.map { c ->
-                CalendarRow(
-                    id = c.id,
-                    displayName = c.displayName,
-                    color = c.color,
-                    visible = c.id !in hidden,
-                )
-            },
-        )
-    }

app/src/main/java/de/jeanlucmakiola/calendula/ui/imports/ImportViewModel.kt

@@ -5,7 +5,6 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.ics.IcsImporter
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventForm
@@ -15,6 +14,7 @@ import de.jeanlucmakiola.calendula.domain.ics.IcsParser
 import de.jeanlucmakiola.calendula.domain.ics.ParsedIcsEvent
 import de.jeanlucmakiola.calendula.domain.ics.toEventForm
 import de.jeanlucmakiola.calendula.domain.isEventTarget
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthChipTime.kt

@@ -7,7 +7,6 @@ import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.ui.common.formatTimeOfDay
 import de.jeanlucmakiola.calendula.ui.common.rememberInlineTimeWidth
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.toLocalDateTime
 import java.util.Locale
 
 /**
@@ -23,8 +22,7 @@ internal fun monthChipTime(
     locale: Locale,
 ): String? {
     if (event.isAllDay || continuesLeft) return null
-    val start = event.start.toLocalDateTime(zone).time
-    return formatTimeOfDay(start.hour, start.minute, is24Hour, locale)
+    return formatTimeOfDay(event.start, zone, is24Hour, locale)
 }
 
 /** The narrowest chip that may show a time — the text it needs, plus its chrome. */

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthDrag.kt

@@ -4,6 +4,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Stable
 import androidx.compose.runtime.compositionLocalOf
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -133,6 +134,10 @@ class MonthDragController {
     var settling: MonthChipDrag? by mutableStateOf(null)
         private set
 
+    /** How many real drops this controller has handed back. */
+    var drops by mutableIntStateOf(0)
+        private set
+
     /**
      * Which chip is lifted, and whether anything is. Separate snapshot state from
      * [drag], which changes every frame, so the chips and rows that only need
@@ -291,6 +296,7 @@ class MonthDragController {
         settledGhost = true
         undoable = settling
         settledAbandonedMark = abandonedTicks?.value ?: 0
+        drops++
         return MonthChipDrop(landed.event, landed.grabDate, target)
     }
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthScreen.kt

@@ -11,6 +11,8 @@ import androidx.compose.foundation.pager.PagerState
 import androidx.compose.foundation.pager.rememberPagerState
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.rememberUpdatedState
+import de.jeanlucmakiola.calendula.ui.agenda.AgendaDay
+import de.jeanlucmakiola.calendula.ui.agenda.agendaDays
 import de.jeanlucmakiola.calendula.ui.common.PublishChrome
 import de.jeanlucmakiola.calendula.ui.common.ScreenActions
 import de.jeanlucmakiola.calendula.ui.common.ScreenBody
@@ -21,7 +23,6 @@ import de.jeanlucmakiola.calendula.ui.common.LocalViewFocus
 import de.jeanlucmakiola.calendula.ui.common.ViewMorphKey
 import de.jeanlucmakiola.calendula.ui.common.morphDay
 import de.jeanlucmakiola.calendula.ui.common.morphEvent
-import de.jeanlucmakiola.calendula.ui.common.morphPageActive
 import de.jeanlucmakiola.calendula.ui.common.jumpToPage
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarPageSpec
 import de.jeanlucmakiola.floret.identity.LocalFloretDarkTheme
@@ -67,7 +68,6 @@ import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
-import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.selection.selectable
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -75,11 +75,7 @@ import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Close
-import androidx.compose.material.icons.filled.Menu
-import androidx.compose.material.icons.filled.Search
-import androidx.compose.material3.DrawerValue
 import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
 import androidx.compose.material3.InputChip
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
@@ -167,8 +163,6 @@ import de.jeanlucmakiola.calendula.ui.agenda.agendaDayLabel
 import de.jeanlucmakiola.calendula.ui.common.formatCalendarTitle
 import de.jeanlucmakiola.calendula.ui.common.AppBarSpacing
 import de.jeanlucmakiola.calendula.ui.common.CalendarFailure
-import de.jeanlucmakiola.calendula.ui.common.CalendarView
-import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
 import de.jeanlucmakiola.calendula.ui.common.LocalDimCutoff
 import de.jeanlucmakiola.calendula.ui.common.isPastOn
@@ -198,10 +192,13 @@ import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.plus
 import kotlinx.datetime.YearMonth
+import kotlinx.datetime.toJavaDayOfWeek
 import kotlinx.datetime.toJavaLocalDate
 import kotlin.time.Instant
 import java.time.format.TextStyle as JavaTextStyle
 import java.util.Locale
+import kotlinx.datetime.toJavaMonth
+import kotlinx.datetime.yearMonth
 
 private val LocalTodayPulse = staticCompositionLocalOf { 0 }
 
@@ -350,7 +347,7 @@ fun MonthScreen(
             if (dense) {
                 val midweek = weekStartForIndex(listState.firstVisibleItemIndex + 1, weekStart)
                     .plus(3, DateTimeUnit.DAY)
-                YearMonth(midweek.year, midweek.month)
+                midweek.yearMonth
             } else {
                 yearMonthForIndex(monthIndexForItem(listState.firstVisibleItemIndex))
             }
@@ -399,7 +396,7 @@ fun MonthScreen(
             }
     }
 
-    val isOnCurrentMonth = titleMonth == YearMonth(today.year, today.month)
+    val isOnCurrentMonth = titleMonth == today.yearMonth
     var splitExpanded by rememberSaveable(viewStyle) {
         mutableStateOf(viewStyle == MonthViewStyle.Paged)
     }
@@ -428,7 +425,7 @@ fun MonthScreen(
     val jumpToToday: () -> Unit = {
         todayPulse++
         if (scrolling) {
-            val targetMonth = YearMonth(today.year, today.month)
+            val targetMonth = today.yearMonth
             pendingScrollMonth = targetMonth
             val requestId = ++scrollRequestId
             viewModel.goToToday()
@@ -446,13 +443,13 @@ fun MonthScreen(
             }
         } else {
             viewModel.goToToday()
-            jumpToMonth(YearMonth(today.year, today.month))
+            jumpToMonth(today.yearMonth)
         }
     }
     // Drawer jump-to-date.
     val jumpToDate: (LocalDate) -> Unit = { target ->
         if (scrolling) {
-            val targetMonth = YearMonth(target.year, target.month)
+            val targetMonth = target.yearMonth
             pendingScrollMonth = targetMonth
             val requestId = ++scrollRequestId
             viewModel.goToDate(target)
@@ -470,7 +467,7 @@ fun MonthScreen(
             }
         } else {
             viewModel.goToDate(target)
-            jumpToMonth(YearMonth(target.year, target.month))
+            jumpToMonth(target.yearMonth)
         }
     }
 
@@ -534,7 +531,7 @@ fun MonthScreen(
                         onOpenDay = onOpenDay,
                         onEventClick = onEventClick,
                     )
-                } else if (viewStyle == MonthViewStyle.Split || viewStyle == MonthViewStyle.Paged) {
+                } else {
                     SplitMonthContent(
                         state = state,
                         selected = selectedDate,
@@ -554,23 +551,12 @@ fun MonthScreen(
                         // still settling would land and take the tap back.
                         onSelectDay = { date ->
                             viewModel.selectDate(date)
-                            jumpToMonth(YearMonth(date.year, date.month))
+                            jumpToMonth(date.yearMonth)
                         },
                         onOpenDay = onOpenDay,
                         onEventClick = onEventClick,
                         onCreateEvent = { onCreateEvent(it, null) },
                     )
-                } else {
-                    MonthContent(
-                        state = state,
-                        pagerState = pagerState,
-                        weekStart = weekStart,
-                        monthState = viewModel::month,
-                        showWeekNumbers = showWeekNumbers,
-                        onRetry = jumpToToday,
-                        onOpenDay = onOpenDay,
-                        onEventClick = onEventClick,
-                    )
                 }
             }
         }
@@ -596,7 +582,7 @@ private fun MonthDragOverlay(controller: MonthDragController) {
     val moveInFlight = moveInFlight()
     // Here rather than beside the controller: this reads [drag], which changes
     // every frame, and this composable is the one that is meant to.
-    DragSnapHaptics(controller.drag?.targetDate)
+    DragSnapHaptics(controller.drag?.targetDate, controller.drops)
     // Hold the landed chip until the write is done — including the time a
     // recurring drop's scope dialog is up — and then, unlike the timeline, carry
     // it to its seat: it was dropped at whatever height the finger was at, while
@@ -679,118 +665,6 @@ private fun MonthDragOverlay(controller: MonthDragController) {
     }
 }
 
-@Composable
-private fun MonthContent(
-    state: MonthUiState,
-    pagerState: PagerState,
-    weekStart: DayOfWeek,
-    monthState: (YearMonth, DayOfWeek) -> StateFlow<MonthUiState>,
-    showWeekNumbers: Boolean,
-    onRetry: () -> Unit,
-    onOpenDay: (LocalDate) -> Unit,
-    onEventClick: (EventInstance) -> Unit,
-) {
-    val fadeSpec = rememberCalendarFadeSpec()
-    // Loading and failure concern the provider as a whole, so they stand in for
-    // the pager; a page still loading its own month handles that itself.
-    AnimatedContent(
-        targetState = state,
-        modifier = Modifier.fillMaxSize(),
-        contentKey = { it::class },
-        transitionSpec = { fadeIn(fadeSpec) togetherWith fadeOut(fadeSpec) },
-        label = "month-state",
-    ) { s ->
-        when (s) {
-            MonthUiState.Loading -> MonthGridLoading()
-            is MonthUiState.Failure -> CalendarFailure(reason = s.reason, onRetry = onRetry)
-            is MonthUiState.Success -> MonthPager(
-                pagerState = pagerState,
-                weekStart = weekStart,
-                monthState = monthState,
-                modifier = Modifier.fillMaxSize(),
-            ) { _, page ->
-                MonthGrid(
-                    state = page,
-                    showWeekNumbers = showWeekNumbers,
-                    onOpenDay = onOpenDay,
-                    onEventClick = onEventClick,
-                )
-            }
-        }
-    }
-}
-
-/**
- * The paged and split styles' months as pages that follow the finger and snap
- * once a swipe passes half a page or is flung (#336). Only the page on screen
- * carries the chip drag and the morph tags: its neighbours show some of its
- * dates among their leading and trailing days, and would otherwise claim its
- * drops and its shared elements.
- */
-@Composable
-private fun MonthPager(
-    pagerState: PagerState,
-    weekStart: DayOfWeek,
-    monthState: (YearMonth, DayOfWeek) -> StateFlow<MonthUiState>,
-    modifier: Modifier = Modifier,
-    loading: @Composable () -> Unit = { MonthGridLoading() },
-    page: @Composable (index: Int, state: MonthUiState.Success) -> Unit,
-) {
-    val chipDrag = LocalMonthDrag.current
-    HorizontalPager(
-        state = pagerState,
-        modifier = modifier,
-        // The months either side are composed ahead, so a swipe lands on a loaded
-        // month rather than watching it fill in.
-        beyondViewportPageCount = 1,
-        verticalAlignment = Alignment.Top,
-        // A held chip moves within its month; the page stays put under it.
-        userScrollEnabled = chipDrag?.isDragging != true,
-        flingBehavior = PagerDefaults.flingBehavior(
-            state = pagerState,
-            snapAnimationSpec = rememberCalendarPageSpec(),
-        ),
-    ) { index ->
-        MonthPage(
-            index = index,
-            active = index == pagerState.currentPage,
-            morphActive = morphPageActive(index, pagerState.settledPage),
-            weekStart = weekStart,
-            monthState = monthState,
-            loading = loading,
-            page = page,
-        )
-    }
-}
-
-@Composable
-private fun MonthPage(
-    index: Int,
-    active: Boolean,
-    morphActive: Boolean,
-    weekStart: DayOfWeek,
-    monthState: (YearMonth, DayOfWeek) -> StateFlow<MonthUiState>,
-    loading: @Composable () -> Unit,
-    page: @Composable (index: Int, state: MonthUiState.Success) -> Unit,
-) {
-    val ym = yearMonthForIndex(index)
-    val state by remember(ym, weekStart) { monthState(ym, weekStart) }.collectAsStateWithLifecycle()
-    val today = LocalMonthToday.current
-    val chipDrag = LocalMonthDrag.current
-    val morph = LocalMonthMorph.current
-    val viewMorph = LocalViewMorph.current
-    CompositionLocalProvider(
-        LocalMonthDrag provides chipDrag.takeIf { active },
-        LocalMonthMorph provides morph.takeIf { active },
-        LocalViewMorph provides viewMorph.takeIf { morphActive },
-    ) {
-        when (val s = state) {
-            is MonthUiState.Success -> page(index, s.withToday(today))
-            else -> loading()
-        }
-    }
-}
-
 /**
  * Content for both scrolling styles. No swipe detector and no [AnimatedContent]:
  * vertical scrolling owns the gesture, and the list never swaps wholesale — it
@@ -850,7 +724,7 @@ internal fun WeekdayHeader(weekStart: DayOfWeek, showWeekNumbers: Boolean) {
         if (showWeekNumbers) Spacer(Modifier.width(rememberWeekNumberGutter()))
         days.forEach { dow ->
             val isWeekend = dow == DayOfWeek.SATURDAY || dow == DayOfWeek.SUNDAY
-            val javaDow = java.time.DayOfWeek.of(dow.ordinal + 1)
+            val javaDow = dow.toJavaDayOfWeek()
             Text(
                 text = javaDow.getDisplayName(JavaTextStyle.SHORT, locale),
                 style = MaterialTheme.typography.labelMedium,
@@ -967,7 +841,7 @@ internal fun monthBandHeight(rowHeight: Dp): Dp =
 
 /** Whether any day in this week holds more than [lanes] lanes can seat. */
 private fun MonthWeek.overflowsAt(lanes: Int): Boolean =
-    days.withIndex().any { (col, day) -> overflowEvents(col, day, lanes).isNotEmpty() }
+    days.indices.any { col -> overflowEvents(col, lanes).isNotEmpty() }
 
 /**
  * Row height in the continuous grid. The paged grid divides the viewport between
@@ -1069,7 +943,7 @@ internal fun ContinuousMonthGrid(
     modifier: Modifier = Modifier,
 ) {
     val monthCount = remember { continuousMonthCount() }
-    val todayMonth = remember(state.today) { YearMonth(state.today.year, state.today.month) }
+    val todayMonth = remember(state.today) { state.today.yearMonth }
     val timeChipWidth = rememberMonthTimeChipWidth()
     LazyColumn(
         state = listState,
@@ -1463,8 +1337,14 @@ private fun SplitMonthContent(
                             showWeekNumbers = showWeekNumbers,
                             expandDrag = expandDrag,
                             onSelectDay = onSelectDay,
-                            onPaneSwipeNext = onPaneSwipeNext,
-                            onPaneSwipePrev = onPaneSwipePrev,
+                            onPaneSwipeNext = {
+                                onPaneSwipeNext()
+                                haptics.performHapticFeedback(HapticFeedbackType.SegmentTick)
+                            },
+                            onPaneSwipePrev = {
+                                onPaneSwipePrev()
+                                haptics.performHapticFeedback(HapticFeedbackType.SegmentTick)
+                            },
                             onClearSelection = onClearSelection,
                             onOpenDay = onOpenDay,
                             onEventClick = onEventClick,
@@ -1747,11 +1627,11 @@ internal fun SplitMonthGrid(
                     val inMonth = day.month == month.month && day.year == month.year
                     // Seated by lane rather than gathered by colour, so each dot
                     // is the event the expanded grid draws in that same lane.
-                    val seated = week.laneEvents(col, day, SPLIT_DOT_LANES)
+                    val seated = week.laneEvents(col, SPLIT_DOT_LANES)
                     SplitDayCell(
                         date = day,
                         events = seated,
-                        hidden = week.overflowEvents(col, day, SPLIT_DOT_LANES),
+                        hidden = week.overflowEvents(col, SPLIT_DOT_LANES),
                         isToday = day == state.today,
                         // A page marks only the days its own month owns. Paging
                         // moves the selection before this month's replacement
@@ -1961,7 +1841,6 @@ private fun SplitDots(
     }
 }
 
-@OptIn(ExperimentalFoundationApi::class)
 @Composable
 private fun SplitMonthAgendaPane(
     state: MonthUiState.Success,
@@ -1979,33 +1858,16 @@ private fun SplitMonthAgendaPane(
     val dimCutoff = LocalDimCutoff.current
     val listState = key(state.month) { rememberLazyListState() }
     LazyColumn(state = listState, contentPadding = PaddingValues(top = 8.dp, bottom = 96.dp)) {
-        days.forEach { day ->
-            val events = state.instancesByDay[day].orEmpty()
-            stickyHeader(key = "header-$day") {
-                AgendaDayHeader(date = day, today = state.today, onOpenDay = onOpenDay)
-            }
-            if (events.isEmpty()) {
-                item(key = "empty-$day") {
-                    AgendaEmptyDayRow(
-                        text = stringResource(R.string.month_split_no_events),
-                        onClick = { onCreateEvent(day) },
-                    )
-                }
-            } else {
-                itemsIndexed(events, key = { _, event -> "$day-${event.instanceId}" }) { index, event ->
-                    AgendaEventRow(
-                        event = event,
-                        day = day,
-                        zone = state.zone,
-                        position = positionOf(index, events.size),
-                        dimmed = dimCutoff != null && event.isPastOn(day, dimCutoff),
-                        modifier = animateItemMotion().morphEvent(ViewMorphKey.event(event, day)),
-                        onClick = { onEventClick(event) },
-                    )
-                }
-            }
-            item(key = "gap-$day") { Spacer(Modifier.height(8.dp)) }
-        }
+        agendaDays(
+            days = days.map { AgendaDay(it, state.instancesByDay[it].orEmpty()) },
+            today = state.today,
+            zone = state.zone,
+            emptyText = R.string.month_split_no_events,
+            onEmptyClick = onCreateEvent,
+            dimmed = { event, day -> dimCutoff != null && event.isPastOn(day, dimCutoff) },
+            onOpenDay = onOpenDay,
+            onEventClick = onEventClick,
+        )
     }
 }
 
@@ -2236,8 +2098,8 @@ private fun MonthWeekRow(
     val ripple = rememberTodayRipple(active = todayCol != null)
     val overflowRow = rememberOverflowRowHeight()
     val laneCap = week.laneCapFor(rowHeight, overflowRow)
-    val laneCount = (week.spans.maxOfOrNull { it.lane } ?: -1) + 1
-    val shownLanes = laneCount.coerceAtMost(laneCap)
+    // Once per row rather than per frame: a drag recomposes every frame.
+    val seatings = remember(week, laneCap) { week.days.indices.map { week.seating(it, laneCap) } }
     val morphing = morphInFlight()
     // Every chip's start time for this row at once, and only when the row's own
     // inputs change: formatting is a parsed pattern per call, and the dim cutoff
@@ -2421,7 +2283,7 @@ private fun MonthWeekRow(
                         .then(if (morphing || dragging) Modifier else Modifier.clipToBounds()),
                 ) {
                     // Spanning bars on their shared lanes.
-                    week.spans.filter { it.lane < shownLanes }.forEach { span ->
+                    week.spans.filter { it.lane < laneCap }.forEach { span ->
                         val cols = span.endCol - span.startCol + 1
                         MonthBar(
                             event = span.event,
@@ -2493,19 +2355,13 @@ private fun MonthWeekRow(
                             )
                         }
                     }
-                    // Single-day timed pills + overflow, per column. Pills fill the
-                    // lane slots no bar occupies on THIS day (top-most first), so a
-                    // bar-free day isn't pushed down by a multi-day event that only
-                    // sits on other days of the week.
+                    // Single-day timed pills + overflow, per column, in the lanes
+                    // [seating] gave them.
                     week.days.forEachIndexed { col, d ->
-                        val timed = week.timedByDay[d].orEmpty()
-                        val occupied = week.spans
-                            .filter { it.lane < shownLanes && col in it.startCol..it.endCol }
-                            .map { it.lane }
-                            .toSet()
-                        val freeSlots = (0 until laneCap).filter { it !in occupied }
-                        val pillsShown = timed.take(freeSlots.size)
-                        pillsShown.forEachIndexed { i, ev ->
+                        val seating = seatings[col]
+                        seating.seated.forEach { seat ->
+                            if (seat.bar) return@forEach
+                            val ev = seat.event
                             MonthBar(
                                 event = ev,
                                 dark = dark,
@@ -2517,7 +2373,7 @@ private fun MonthWeekRow(
                                 modifier = Modifier
                                     .offset(
                                         x = colW * col,
-                                        y = EVENT_ROW_HEIGHT * freeSlots[i],
+                                        y = EVENT_ROW_HEIGHT * seat.lane,
                                     )
                                     .morphBounds(MonthMorphKey.Event(d, ev.instanceId))
                                     .then(
@@ -2533,18 +2389,10 @@ private fun MonthWeekRow(
                                     .padding(horizontal = MONTH_CHIP_INSET, vertical = 1.dp),
                             )
                         }
-                        val hidden = (week.countByDay[d] ?: 0) - occupied.size - pillsShown.size
-                        if (hidden > 0) {
-                            val hiddenEvents = buildList {
-                                week.spans
-                                    .filter { it.lane >= shownLanes && col in it.startCol..it.endCol }
-                                    .forEach { add(it.event) }
-                                addAll(timed.drop(pillsShown.size))
-                            }
+                        if (seating.hidden.isNotEmpty()) {
                             OverflowDots(
-                                events = hiddenEvents,
+                                events = seating.hidden,
                                 day = d,
-                                total = hidden,
                                 dark = dark,
                                 rowHeight = overflowRow,
                                 modifier = Modifier
@@ -2839,7 +2687,7 @@ private fun DayNumberCell(
 private fun shortMonthName(date: LocalDate): String {
     val locale = currentLocale()
     return remember(date.month, locale) {
-        java.time.Month.of(date.month.ordinal + 1)
+        date.month.toJavaMonth()
             .getDisplayName(JavaTextStyle.SHORT, locale)
     }
 }
@@ -2924,7 +2772,6 @@ private fun MonthBar(
 private fun OverflowDots(
     events: List<EventInstance>,
     day: LocalDate,
-    total: Int,
     dark: Boolean,
     rowHeight: Dp,
     modifier: Modifier = Modifier,
@@ -2946,7 +2793,7 @@ private fun OverflowDots(
                     .background(eventAccent(argb, dark, soften), CircleShape),
             )
         }
-        val extra = total - dots.size
+        val extra = events.size - dots.size
         if (extra > 0) {
             Text(
                 text = "+$extra",
@@ -3002,7 +2849,7 @@ private fun formatMonthTitle(
     abbreviated: Boolean = false,
 ): String =
     formatCalendarTitle(
-        date = java.time.LocalDate.of(ym.year, ym.month.ordinal + 1, 1),
+        date = ym.firstDay.toJavaLocalDate(),
         locale = locale,
         currentYear = currentYear,
         skeleton = if (abbreviated) "LLL" else "LLLL",

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthStylePreview.kt

@@ -8,16 +8,16 @@ import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
-import de.jeanlucmakiola.calendula.ui.common.ScaledViewPreview
 import de.jeanlucmakiola.calendula.ui.common.sampleMonthEvents
+import de.jeanlucmakiola.floret.components.ScaledViewPreview
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
-import kotlinx.datetime.YearMonth
 import kotlinx.datetime.plus
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Clock
+import kotlinx.datetime.yearMonth
 
 /**
  * A live, scaled-down Month view in a given [MonthViewStyle], for the settings
@@ -51,7 +51,7 @@ internal fun MonthStylePreview(
                 state = sample.continuous,
                 listState = rememberLazyListState(
                     initialFirstVisibleItemIndex = itemIndexForMonth(
-                        monthIndexOf(YearMonth(today.year, today.month)),
+                        monthIndexOf(today.yearMonth),
                     ),
                 ),
                 showWeekNumbers = false,
@@ -109,7 +109,7 @@ private fun sampleMonthState(
     weekStart: DayOfWeek,
     zone: TimeZone,
 ): SampleMonth {
-    val ym = YearMonth(today.year, today.month)
+    val ym = today.yearMonth
     val first = LocalDate(ym.year, ym.month, 1)
     val events = sampleMonthEvents(first, today, zone)
 

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthUiState.kt

@@ -39,33 +39,55 @@ data class MonthWeek(
     val countByDay: Map<LocalDate, Int>,
 )
 
+/** One event seated in [lane] of a day; [bar] is a spanning bar rather than that day's own pill. */
+data class Seat(val lane: Int, val event: EventInstance, val bar: Boolean)
+
 /**
- * The events occupying each lane of [day] — column [col] of this week — in lane
- * order, capped at [laneCap] lanes.
+ * How one day of a week row is seated with [laneCap] lanes: what sits in each
+ * lane, top-most first with empty lanes left out, and what had no lane left.
+ */
+data class DaySeating(val seated: List<Seat>, val hidden: List<EventInstance>)
+
+/**
+ * The seating of column [col] with [laneCap] lanes — the one every reader of a
+ * row builds on: the bars and pills the paged grid draws, the split style's dots
+ * ([laneEvents]), the hit test ([chipAt]) and the overflow ([overflowEvents]).
  *
- * This is the same seating [spans]/[timedByDay] get when the paged grid draws a
- * week: bars keep the lane the row layout gave them, and the day's timed events
- * fill whatever slots are left, top-most first. Reading it here means the split
- * style's dots and the paged style's bars describe a day in the *same order*, so
- * dot _i_ and lane _i_ are the same event and one can morph into the other (#53).
+ * Bars keep the lane the row layout gave them, and the day's timed events fill
+ * whatever slots are left, top-most first, so a bar-free day isn't pushed down by
+ * a multi-day event that only sits on other days of the week. Overflow is the
+ * exact complement, bars before pills.
+ */
+fun MonthWeek.seating(col: Int, laneCap: Int): DaySeating {
+    val covering = spans.filter { col in it.startCol..it.endCol }
+    val byLane = arrayOfNulls<Seat>(laneCap.coerceAtLeast(0))
+    covering.forEach { span ->
+        if (span.lane < laneCap) byLane[span.lane] = Seat(span.lane, span.event, bar = true)
+    }
+    val timed = timedByDay[days[col]].orEmpty()
+    var pills = 0
+    for (lane in byLane.indices) {
+        if (byLane[lane] == null && pills < timed.size) byLane[lane] = Seat(lane, timed[pills++], bar = false)
+    }
+    return DaySeating(
+        seated = byLane.filterNotNull(),
+        hidden = covering.filter { it.lane >= laneCap }.map { it.event } + timed.drop(pills),
+    )
+}
+
+/**
+ * The events occupying each lane of column [col], in lane order, capped at
+ * [laneCap] lanes — the same [seating] the paged grid draws a week with. Reading
+ * it here means the split style's dots and the paged style's bars describe a day
+ * in the *same order*, so dot _i_ and lane _i_ are the same event and one can
+ * morph into the other (#53).
  *
  * Deriving the dots independently — by distinct colour, as they first were —
  * left dot _i_ standing for no particular event, and quietly merged two events
  * that shared a calendar into a single dot.
  */
-fun MonthWeek.laneEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInstance> {
-    val byLane = arrayOfNulls<EventInstance>(laneCap)
-    spans.forEach { span ->
-        if (span.lane < laneCap && col in span.startCol..span.endCol) {
-            byLane[span.lane] = span.event
-        }
-    }
-    val free = (0 until laneCap).filter { byLane[it] == null }
-    timedByDay[day].orEmpty().take(free.size).forEachIndexed { i, event ->
-        byLane[free[i]] = event
-    }
-    return byLane.filterNotNull()
-}
+fun MonthWeek.laneEvents(col: Int, laneCap: Int): List<EventInstance> =
+    seating(col, laneCap).seated.map { it.event }
 
 /**
  * The event drawn in lane [lane] of column [col], or null for an empty slot.
@@ -74,14 +96,7 @@ fun MonthWeek.laneEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInst
  */
 fun MonthWeek.chipAt(col: Int, lane: Int, laneCap: Int): EventInstance? {
     if (col !in days.indices || lane !in 0 until laneCap) return null
-    spanAt(col, lane)?.let { return it.event }
-    val occupied = spans
-        .filter { it.lane < laneCap && col in it.startCol..it.endCol }
-        .map { it.lane }
-        .toSet()
-    val free = (0 until laneCap).filter { it !in occupied }
-    val index = free.indexOf(lane).takeIf { it >= 0 } ?: return null
-    return timedByDay[days[col]].orEmpty().take(free.size).getOrNull(index)
+    return seating(col, laneCap).seated.firstOrNull { it.lane == lane }?.event
 }
 
 /**
@@ -98,19 +113,11 @@ fun MonthWeek.spanAt(col: Int, lane: Int): MonthSpan? =
     spans.firstOrNull { it.lane == lane && col in it.startCol..it.endCol }
 
 /**
- * The events on [day] that [laneEvents] had no lane left for — its exact
+ * The events in column [col] that [laneEvents] had no lane left for — its exact
  * complement, in the same bars-then-pills order. Returned as events rather than
  * a count because dimming is a per-event question (#79).
  */
-fun MonthWeek.overflowEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInstance> {
-    val seatedLanes = spans.count { it.lane < laneCap && col in it.startCol..it.endCol }
-    return buildList {
-        spans.forEach { span ->
-            if (span.lane >= laneCap && col in span.startCol..span.endCol) add(span.event)
-        }
-        addAll(timedByDay[day].orEmpty().drop(laneCap - seatedLanes))
-    }
-}
+fun MonthWeek.overflowEvents(col: Int, laneCap: Int): List<EventInstance> = seating(col, laneCap).hidden
 
 /**
  * State for the continuous style (#38): a vertical stream of *self-contained*

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthViewModel.kt

@@ -1,14 +1,16 @@
 package de.jeanlucmakiola.calendula.ui.month
 
+import de.jeanlucmakiola.calendula.ui.common.startOfWeek
+import de.jeanlucmakiola.calendula.ui.common.dayRange
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.firstDayOfWeek
 import de.jeanlucmakiola.calendula.data.time.TodaySource
 import de.jeanlucmakiola.calendula.data.time.currentDate
+import de.jeanlucmakiola.calendula.data.time.stateFollowingDays
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventInstance
 import de.jeanlucmakiola.calendula.domain.FailureReason
@@ -19,10 +21,11 @@ import de.jeanlucmakiola.calendula.domain.eventDisplayComparator
 import de.jeanlucmakiola.calendula.ui.week.coversDay
 import de.jeanlucmakiola.calendula.ui.week.layoutAllDay
 import de.jeanlucmakiola.calendula.ui.week.spansMultipleDays
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.combine
@@ -33,22 +36,19 @@ import kotlinx.coroutines.flow.filterNot
 import kotlinx.coroutines.flow.map
 import kotlin.math.abs
 import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.stateIn
 import kotlinx.datetime.DateTimeUnit
 import kotlinx.datetime.DayOfWeek
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.Month
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.YearMonth
-import kotlinx.datetime.atStartOfDayIn
-import kotlinx.datetime.atTime
 import kotlinx.datetime.daysUntil
 import kotlinx.datetime.minus
 import kotlinx.datetime.plus
-import kotlinx.datetime.toInstant
 import kotlinx.datetime.toLocalDateTime
 import kotlin.time.Instant
 import javax.inject.Inject
+import kotlinx.datetime.yearMonth
 
 /** How many months either side of the requested one [MonthViewModel.month] keeps cached. */
 private const val MONTH_CACHE_SPAN = 2
@@ -69,54 +69,35 @@ class MonthViewModel @Inject constructor(
 
     /** Whether to fade events that have already finished (display concern only). */
     val dimCompletedEvents: StateFlow<Boolean> = settingsPrefs.dimCompletedEvents
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = false,
         )
 
     /** Whether to show the calendar-week number gutter (#25; display only). */
     val showWeekNumbers: StateFlow<Boolean> = settingsPrefs.showWeekNumbers
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = false,
         )
 
     /** How the grid is laid out and navigated (#38, #53). */
     val viewStyle: StateFlow<MonthViewStyle> = settingsPrefs.monthViewStyle
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = MonthViewStyle.Paged,
         )
 
     private val todayDate: LocalDate
         get() = currentDate()
 
-    private var lastToday = todayDate
-
     /** Today, kept current across midnight so a grid left open doesn't mark yesterday (#373). */
-    val today: StateFlow<LocalDate> = todaySource.today
-        .onEach { date ->
-            val old = lastToday
-            lastToday = date
-            if (old != date) followToday(old, date)
-        }
-        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000L), todayDate)
+    val today: StateFlow<LocalDate> =
+        todaySource.today.stateFollowingDays(viewModelScope, todayDate, ::followToday)
 
-    private val _month = MutableStateFlow(YearMonth(todayDate.year, todayDate.month))
+    private val _month = MutableStateFlow(todayDate.yearMonth)
     val month: StateFlow<YearMonth> = _month
 
-    /** The pager page the anchor month sits on, for the paged and split styles. */
-    val anchorPage: StateFlow<Int> = _month
-        .map { monthIndexOf(it) }
-        .stateIn(
-            scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
-            initialValue = monthIndexOf(_month.value),
-        )
-
     /**
      * The anchor month's state. Once loaded it never falls back to
      * [MonthUiState.Loading]: moving the anchor keeps the last result until the
@@ -133,9 +114,8 @@ class MonthViewModel @Inject constructor(
                 month(ym, ws).filterNot { it is MonthUiState.Loading }
             }
             .catch { emit(MonthUiState.Failure(FailureReason.ProviderUnavailable)) }
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = MonthUiState.Loading,
             )
 
@@ -170,7 +150,8 @@ class MonthViewModel @Inject constructor(
     fun onPageSettled(page: Int) {
         if (monthIndexOf(_month.value) == page) return
         _month.value = yearMonthForIndex(page)
-        realignSelection()
+        // Moving the grid to another month restores its full agenda.
+        _selectedDate.value = null
     }
 
     // --- Continuous + Dense styles (#38) ----------------------------------
@@ -195,11 +176,11 @@ class MonthViewModel @Inject constructor(
 
     /** Last reported visible range, so a widening step can re-centre on it. */
     @Volatile
-    private var visibleMonths = monthIndexOf(YearMonth(todayDate.year, todayDate.month))
+    private var visibleMonths = monthIndexOf(todayDate.yearMonth)
         .let { it..it }
 
     private val _loadedMonths = MutableStateFlow(
-        monthIndexOf(YearMonth(todayDate.year, todayDate.month))
+        monthIndexOf(todayDate.yearMonth)
             .let { clampMonthWindow(it - INITIAL_PAD..it + INITIAL_PAD) },
     )
 
@@ -215,13 +196,11 @@ class MonthViewModel @Inject constructor(
                 // Widened to whole grid weeks at both ends: a month block still
                 // has to know about an event that starts in the boundary week's
                 // clipped-off days, or a bar running into the block would vanish.
-                val first = firstOfMonth(yearMonthForIndex(window.first)).startOfGridWeek(ws)
-                val last = firstOfMonth(yearMonthForIndex(window.last))
-                    .plus(1, DateTimeUnit.MONTH)
-                    .minus(1, DateTimeUnit.DAY)
-                    .startOfGridWeek(ws)
+                val first = yearMonthForIndex(window.first).firstDay.startOfWeek(ws)
+                val last = yearMonthForIndex(window.last).lastDay
+                    .startOfWeek(ws)
                     .plus(6, DateTimeUnit.DAY)
-                val range = first.atStartOfDayIn(zone)..last.atTime(23, 59, 59).toInstant(zone)
+                val range = dayRange(first, last, zone)
                 combine(
                     repository.calendars(),
                     repository.instances(range),
@@ -236,9 +215,8 @@ class MonthViewModel @Inject constructor(
             .onEach { if (it is ContinuousMonthUiState.Success) widenLoadedWindow() }
             .catch { emit(ContinuousMonthUiState.Failure(FailureReason.ProviderUnavailable)) }
             .flowOn(io)
-            .stateIn(
+            .stateWhileSubscribed(
                 scope = viewModelScope,
-                started = SharingStarted.WhileSubscribed(5_000L),
                 initialValue = ContinuousMonthUiState.Loading,
             )
 
@@ -320,7 +298,7 @@ class MonthViewModel @Inject constructor(
      * silently list a date the grid isn't pointing at.
      */
     fun selectDate(date: LocalDate) {
-        val target = YearMonth(date.year, date.month)
+        val target = date.yearMonth
         _selectedDate.value = if (target == _month.value && _selectedDate.value == date) null else date
         if (target != _month.value) _month.value = target
     }
@@ -335,17 +313,12 @@ class MonthViewModel @Inject constructor(
         } else {
             val next = selected.plus(days, DateTimeUnit.DAY)
             _selectedDate.value = next
-            _month.value = YearMonth(next.year, next.month)
+            _month.value = next.yearMonth
         }
     }
 
-    /** Moving the grid to another month restores its full agenda. */
-    private fun realignSelection() {
-        _selectedDate.value = null
-    }
-
     fun goToToday() {
-        _month.value = YearMonth(todayDate.year, todayDate.month)
+        _month.value = todayDate.yearMonth
         _selectedDate.value = null
     }
 
@@ -356,8 +329,8 @@ class MonthViewModel @Inject constructor(
      */
     private fun followToday(old: LocalDate, new: LocalDate) {
         if (viewStyle.value.isScrolling) return
-        if (_month.value != YearMonth(old.year, old.month)) return
-        _month.value = YearMonth(new.year, new.month)
+        if (_month.value != old.yearMonth) return
+        _month.value = new.yearMonth
         _selectedDate.value = null
     }
 
@@ -377,7 +350,7 @@ class MonthViewModel @Inject constructor(
 
     /** Jump to the month containing [date] (drawer jump-to-date). */
     fun goToDate(date: LocalDate) {
-        _month.value = YearMonth(date.year, date.month)
+        _month.value = date.yearMonth
         _selectedDate.value = date
     }
 
@@ -427,7 +400,7 @@ internal fun layoutMonthWeeks(
     byDay: DayIndex,
     zone: TimeZone,
 ): List<MonthWeek> {
-    val gridStart = firstOfMonth(ym).startOfGridWeek(weekStart)
+    val gridStart = ym.firstDay.startOfWeek(weekStart)
     val weekCount = weekRowsInMonth(ym, weekStart)
 
     return (0 until weekCount).map { row ->
@@ -548,12 +521,8 @@ internal fun monthGridRange(
     weekStart: DayOfWeek,
     zone: TimeZone,
 ): ClosedRange<Instant> {
-    val firstOfMonth = LocalDate(ym.year, ym.month, 1)
-    val gridStart = firstOfMonth.startOfGridWeek(weekStart)
-    val gridEnd = gridStart.plus(41, DateTimeUnit.DAY)
-    val start = gridStart.atStartOfDayIn(zone)
-    val end = gridEnd.atTime(23, 59, 59).toInstant(zone)
-    return start..end
+    val gridStart = ym.firstDay.startOfWeek(weekStart)
+    return dayRange(gridStart, gridStart.plus(41, DateTimeUnit.DAY), zone)
 }
 
 /**
@@ -581,7 +550,7 @@ internal fun edgeForPad(pad: Int): Int = minOf(WINDOW_EDGE, pad - 1).coerceAtLea
  * the first of the visible month.
  */
 internal fun agendaStartForMonth(month: YearMonth, today: LocalDate): LocalDate =
-    if (YearMonth(today.year, today.month) == month) {
+    if (today.yearMonth == month) {
         today
     } else {
         LocalDate(month.year, month.month, 1)
@@ -649,8 +618,6 @@ internal fun clampMonthWindow(window: IntRange): IntRange {
     return window.first.coerceIn(0, last)..window.last.coerceIn(0, last)
 }
 
-internal fun firstOfMonth(ym: YearMonth): LocalDate = LocalDate(ym.year, ym.month, 1)
-
 /**
  * The Dense style addresses *weeks* by absolute index instead: it has no month
  * blocks to key by, and a row's identity has to survive the months around it
@@ -665,12 +632,12 @@ private val WEEK_INDEX_EPOCH = LocalDate(1900, 1, 1)
 private val WEEK_INDEX_END = LocalDate(2100, 12, 31)
 
 internal fun weekIndexOf(date: LocalDate, weekStart: DayOfWeek): Int {
-    val base = WEEK_INDEX_EPOCH.startOfGridWeek(weekStart)
-    return base.daysUntil(date.startOfGridWeek(weekStart)) / 7
+    val base = WEEK_INDEX_EPOCH.startOfWeek(weekStart)
+    return base.daysUntil(date.startOfWeek(weekStart)) / 7
 }
 
 internal fun weekStartForIndex(index: Int, weekStart: DayOfWeek): LocalDate =
-    WEEK_INDEX_EPOCH.startOfGridWeek(weekStart).plus(index * 7, DateTimeUnit.DAY)
+    WEEK_INDEX_EPOCH.startOfWeek(weekStart).plus(index * 7, DateTimeUnit.DAY)
 
 /** Total weeks the Dense grid scrolls through (1900 → 2100). */
 internal fun continuousWeekCount(weekStart: DayOfWeek): Int =
@@ -681,7 +648,7 @@ internal fun monthIndexForWeek(weekIndex: Int, weekStart: DayOfWeek): Int {
     // The row's midweek day: a boundary week is reported as whichever month owns
     // most of it, the same rule the title uses.
     val midweek = weekStartForIndex(weekIndex, weekStart).plus(3, DateTimeUnit.DAY)
-    return monthIndexOf(YearMonth(midweek.year, midweek.month))
+    return monthIndexOf(midweek.yearMonth)
 }
 
 /**
@@ -690,19 +657,16 @@ internal fun monthIndexForWeek(weekIndex: Int, weekStart: DayOfWeek): Int {
  * laid out too, rather than flickering as placeholders.
  */
 internal fun weekWindowFor(window: IntRange, weekStart: DayOfWeek): IntRange {
-    val first = weekIndexOf(firstOfMonth(yearMonthForIndex(window.first)), weekStart) - 1
-    val lastMonthEnd = firstOfMonth(yearMonthForIndex(window.last))
-        .plus(1, DateTimeUnit.MONTH)
-        .minus(1, DateTimeUnit.DAY)
+    val first = weekIndexOf(yearMonthForIndex(window.first).firstDay, weekStart) - 1
+    val lastMonthEnd = yearMonthForIndex(window.last).lastDay
     return first..(weekIndexOf(lastMonthEnd, weekStart) + 1)
 }
 
 /** How many week rows [ym] needs under [weekStart] — 4 (a non-leap February), 5 or 6. */
 internal fun weekRowsInMonth(ym: YearMonth, weekStart: DayOfWeek): Int {
-    val first = firstOfMonth(ym)
+    val first = ym.firstDay
     val leadOffset = ((first.dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7
-    val daysInMonth = java.time.YearMonth.of(ym.year, ym.month.ordinal + 1).lengthOfMonth()
-    return (leadOffset + daysInMonth + 6) / 7
+    return (leadOffset + ym.numberOfDays + 6) / 7
 }
 
 /**
@@ -746,9 +710,3 @@ internal fun clipWeekToMonth(week: MonthWeek, month: YearMonth): MonthWeek {
         countByDay = week.countByDay.filterKeys { it in own },
     )
 }
-
-internal fun LocalDate.startOfGridWeek(weekStart: DayOfWeek): LocalDate {
-    // DayOfWeek.ordinal: MONDAY=0..SUNDAY=6 → identical to ISO ordering.
-    val offset = ((dayOfWeek.ordinal - weekStart.ordinal) + 7) % 7
-    return minus(offset, DateTimeUnit.DAY)
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/BackupStep.kt

@@ -10,17 +10,14 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.CloudOff
 import androidx.compose.material.icons.filled.FolderOpen
 import androidx.compose.material.icons.filled.Schedule
-import androidx.compose.material3.Button
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.floret.components.BenefitRow
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -53,15 +50,10 @@ internal fun BackupStep(
         topSpacing = OnboardingSpace.lg,
         hero = { IconHero(Icons.Filled.CloudOff) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.onboarding_backup_enable_button),
                 onClick = { runCatching { pickFolder.launch(null) } },
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.onboarding_backup_enable_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
             TextButton(
                 onClick = onSkip,
                 modifier = Modifier.fillMaxWidth(),
@@ -69,20 +61,9 @@ internal fun BackupStep(
                 Text(stringResource(R.string.onboarding_backup_skip_button))
             }
         },
+        headline = stringResource(R.string.onboarding_backup_title),
+        supporting = stringResource(R.string.onboarding_backup_body),
     ) {
-        Text(
-            text = stringResource(R.string.onboarding_backup_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.onboarding_backup_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-
         Spacer(Modifier.height(OnboardingSpace.lg))
 
         BenefitRow(

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/CalendarsStep.kt

@@ -9,7 +9,6 @@ import androidx.compose.material.icons.filled.CheckCircle
 import androidx.compose.material.icons.filled.CloudSync
 import androidx.compose.material.icons.filled.PhoneAndroid
 import androidx.compose.material.icons.filled.Settings
-import androidx.compose.material3.Button
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.Text
@@ -30,6 +29,7 @@ import de.jeanlucmakiola.calendula.data.calendar.CalendarColorPalette
 import de.jeanlucmakiola.calendula.ui.calendars.CalendarEditor
 import de.jeanlucmakiola.calendula.ui.settings.openUrl
 import de.jeanlucmakiola.floret.components.BenefitRow
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -108,18 +108,13 @@ internal fun CalendarsStep(
         topSpacing = OnboardingSpace.lg,
         hero = { IconHero(Icons.Filled.CalendarMonth) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.onboarding_calendars_local_button),
                 onClick = {
                     onClearCreation()
                     creating = true
                 },
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.onboarding_calendars_local_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
             OutlinedButton(
                 onClick = { openUrl(context, DAVX5_URL) },
                 modifier = Modifier.fillMaxWidth().height(56.dp),
@@ -133,20 +128,9 @@ internal fun CalendarsStep(
                 Text(stringResource(R.string.onboarding_calendars_skip_button))
             }
         },
+        headline = stringResource(R.string.onboarding_calendars_title),
+        supporting = stringResource(R.string.onboarding_calendars_body),
     ) {
-        Text(
-            text = stringResource(R.string.onboarding_calendars_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.onboarding_calendars_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-
         if (creation is CalendarCreation.Failed) {
             Spacer(Modifier.height(12.dp))
             Text(
@@ -189,30 +173,14 @@ private fun CalendarCreated(
         topSpacing = OnboardingSpace.lg,
         hero = { IconHero(Icons.Filled.CheckCircle) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.onboarding_calendars_created_continue),
                 onClick = onContinue,
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.onboarding_calendars_created_continue),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
         },
+        headline = stringResource(R.string.onboarding_calendars_created_title, name),
+        supporting = stringResource(R.string.onboarding_calendars_created_body),
     ) {
-        Text(
-            text = stringResource(R.string.onboarding_calendars_created_title, name),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.onboarding_calendars_created_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-
         Spacer(Modifier.height(OnboardingSpace.lg))
 
         BenefitRow(

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/DoneStep.kt

@@ -1,17 +1,10 @@
 package de.jeanlucmakiola.calendula.ui.onboarding
 
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
-import androidx.compose.material3.Button
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -34,28 +27,12 @@ internal fun DoneStep(
         topSpacing = OnboardingSpace.lg,
         hero = { BrandHero(HeroBadge.Done) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.onboarding_done_button),
                 onClick = onFinished,
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.onboarding_done_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
         },
-    ) {
-        Text(
-            text = stringResource(R.string.onboarding_done_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.onboarding_done_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-    }
+        headline = stringResource(R.string.onboarding_done_title),
+        supporting = stringResource(R.string.onboarding_done_body),
+    )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/HiddenCalendarsStep.kt

@@ -7,24 +7,23 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.VisibilityOff
-import androidx.compose.material3.Button
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.semantics.contentDescription
-import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.hasVisibilitySwitch
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
+import de.jeanlucmakiola.calendula.ui.common.CalendarVisibilitySwitch
+import de.jeanlucmakiola.calendula.ui.common.orUnnamed
 import de.jeanlucmakiola.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.GroupedRow
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 import de.jeanlucmakiola.floret.components.Position
@@ -65,24 +64,17 @@ internal fun HiddenCalendarsStep(
         scrollingActions = true,
         hero = { IconHero(Icons.Filled.VisibilityOff) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(
+                    if (anyVisible) {
+                        R.string.onboarding_view_continue_button
+                    } else {
+                        R.string.onboarding_hidden_switch_all_button
+                    },
+                ),
                 onClick = if (anyVisible) onFinished else onSwitchAllOn,
-                modifier = Modifier
-                    .padding(horizontal = GroupedListInset)
-                    .fillMaxWidth()
-                    .height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(
-                        if (anyVisible) {
-                            R.string.onboarding_view_continue_button
-                        } else {
-                            R.string.onboarding_hidden_switch_all_button
-                        },
-                    ),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+                modifier = Modifier.padding(horizontal = GroupedListInset),
+            )
             // Only while nothing is on: once something is, the step has been
             // answered and the one button left to press says so.
             if (!anyVisible) {
@@ -129,7 +121,7 @@ internal fun HiddenCalendarsStep(
         calendars.forEachIndexed { index, calendar ->
             val off = !calendar.isVisibleInSystem
             GroupedRow(
-                title = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
+                title = calendar.displayName.orUnnamed(),
                 summary = calendar.accountName.takeIf { it.isNotBlank() },
                 position = when {
                     calendars.size == 1 -> Position.Alone
@@ -140,8 +132,8 @@ internal fun HiddenCalendarsStep(
                 dimmed = off,
                 trailing = if (calendar.hasVisibilitySwitch) {
                     {
-                        CalendarSwitch(
-                            calendarName = calendar.displayName.ifBlank { stringResource(R.string.calendar_unnamed) },
+                        CalendarVisibilitySwitch(
+                            calendarName = calendar.displayName.orUnnamed(),
                             enabled = !off,
                             onToggle = { on -> onSetVisible(calendar.id, on) },
                         )
@@ -156,18 +148,3 @@ internal fun HiddenCalendarsStep(
         Spacer(Modifier.height(OnboardingSpace.md))
     }
 }
-
-/** The per-row switch, writing the device's own `Calendars.VISIBLE` as Settings does. */
-@Composable
-private fun CalendarSwitch(
-    calendarName: String,
-    enabled: Boolean,
-    onToggle: (Boolean) -> Unit,
-) {
-    val label = stringResource(R.string.calendars_visibility_a11y, calendarName)
-    Switch(
-        checked = enabled,
-        onCheckedChange = onToggle,
-        modifier = Modifier.semantics { contentDescription = label },
-    )
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/OnboardingViewModel.kt

@@ -10,7 +10,6 @@ import dagger.hilt.android.qualifiers.ApplicationContext
 import de.jeanlucmakiola.calendula.data.backup.BackupScheduler
 import de.jeanlucmakiola.calendula.data.calendar.CalendarRepository
 import de.jeanlucmakiola.calendula.data.calendar.CalendarVisibilityReconciler
-import de.jeanlucmakiola.calendula.data.di.IoDispatcher
 import de.jeanlucmakiola.calendula.data.prefs.CalendarPrefs
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.data.prefs.WeekStartPref
@@ -20,6 +19,8 @@ import de.jeanlucmakiola.calendula.domain.hasVisibilitySwitch
 import de.jeanlucmakiola.calendula.domain.orderedForManager
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
+import de.jeanlucmakiola.floret.android.stateWhileSubscribed
+import de.jeanlucmakiola.floret.di.IoDispatcher
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
@@ -92,9 +93,8 @@ class OnboardingViewModel @Inject constructor(
                 list.catch { emit(null) }.flowOn(io)
             }
         }
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = null,
         )
 
@@ -166,15 +166,6 @@ class OnboardingViewModel @Inject constructor(
         hiddenTouched,
     ) { hidden, touched -> if (touched) null else hidden }
 
-    /** Both calendar steps' inputs: what each applies to, and whether it is answered. */
-    private val calendarsFlags: Flow<CalendarsFlags> = combine(
-        calendarsApplies,
-        prefs.onboardingCalendarsDone,
-        hiddenApplies,
-        prefs.onboardingHiddenCalendarsDone,
-        ::CalendarsFlags,
-    )
-
     /**
      * The calendars the hidden-calendars step lists, so the user can judge which
      * to switch on rather than take the app's word that there are some. Live: a
@@ -183,58 +174,44 @@ class OnboardingViewModel @Inject constructor(
      */
     val hiddenCalendars: StateFlow<List<CalendarSource>> = calendars
         .map { it.orEmpty().orderedForManager() }
-        .stateIn(
+        .stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = emptyList(),
         )
 
-    private val flags: Flow<OnboardingFlags> = combine(
-        prefs.reminderOnboardingDone,
-        prefs.onboardingWizardArmed,
-        prefs.onboardingBackupDone,
-        prefs.onboardingViewDone,
-        prefs.onboardingMonthStyleDone,
-        ::OnboardingFlags,
-    )
-
-    /** The closing steps' own flags, and whether the notice applies at all. */
-    private val closingFlags: Flow<ClosingFlags> = combine(
-        calendarPrefs.visibilityNoticePending.map { it == true },
-        prefs.onboardingVisibilityDone,
-        prefs.onboardingDoneShown,
-        ::ClosingFlags,
-    )
+    /** What the two calendar steps apply to (#287). */
+    private val calendarStepsApply: Flow<Pair<Boolean?, Boolean?>> =
+        combine(calendarsApplies, hiddenApplies, ::Pair)
 
     val plan: StateFlow<OnboardingPlan?> =
         combine(
             hasPermission,
-            flags,
-            closingFlags,
+            prefs.onboardingProgress,
+            calendarPrefs.visibilityNoticePending.map { it == true },
             backupApplies,
-            calendarsFlags,
-        ) { granted, stored, closing, backup, calendars ->
+            calendarStepsApply,
+        ) { granted, progress, visibilityArmed, backup, (calendars, hidden) ->
+            val answered = progress.answered
             granted?.let {
                 onboardingPlan(
                     hasPermission = it,
-                    remindersDone = stored.remindersDone,
-                    wizardArmed = stored.wizardArmed,
-                    backupDone = stored.backupDone,
-                    viewDone = stored.viewDone,
-                    monthStyleDone = stored.monthStyleDone,
+                    remindersDone = OnboardingStep.Reminders in answered,
+                    wizardArmed = progress.wizardArmed,
+                    backupDone = OnboardingStep.Backup in answered,
+                    viewDone = OnboardingStep.View in answered,
+                    monthStyleDone = OnboardingStep.MonthStyle in answered,
                     backupApplies = backup,
-                    hiddenDone = calendars.hiddenDone,
-                    hiddenApplies = calendars.hiddenApplies,
-                    calendarsDone = calendars.done,
-                    calendarsApplies = calendars.applies,
-                    visibilityArmed = closing.visibilityArmed,
-                    visibilityDone = closing.visibilityDone,
-                    doneShown = closing.doneShown,
+                    hiddenDone = OnboardingStep.HiddenCalendars in answered,
+                    hiddenApplies = hidden,
+                    calendarsDone = OnboardingStep.Calendars in answered,
+                    calendarsApplies = calendars,
+                    visibilityArmed = visibilityArmed,
+                    visibilityDone = OnboardingStep.Visibility in answered,
+                    doneShown = OnboardingStep.Done in answered,
                 )
             }
-        }.stateIn(
+        }.stateWhileSubscribed(
             scope = viewModelScope,
-            started = SharingStarted.WhileSubscribed(5_000L),
             initialValue = null,
         )
 
@@ -244,9 +221,8 @@ class OnboardingViewModel @Inject constructor(
         prefs.monthViewStyle,
         prefs.weekStart,
         ::ViewChoice,
-    ).stateIn(
+    ).stateWhileSubscribed(
         scope = viewModelScope,
-        started = SharingStarted.WhileSubscribed(5_000L),
         initialValue = null,
     )
 
@@ -261,7 +237,7 @@ class OnboardingViewModel @Inject constructor(
      * to a restarted process, leaving them the reminder step alone.
      */
     private suspend fun armWizardIfFresh() {
-        if (!prefs.reminderOnboardingDone.first()) prefs.armOnboardingWizard()
+        prefs.armOnboardingWizard()
     }
 
     /**
@@ -277,7 +253,7 @@ class OnboardingViewModel @Inject constructor(
     fun finishReminders(remindersEnabled: Boolean) {
         viewModelScope.launch {
             prefs.setRemindersEnabled(remindersEnabled)
-            prefs.setReminderOnboardingDone()
+            prefs.setOnboardingDone(OnboardingStep.Reminders)
             // Nothing else re-arms the scan: turning reminders off cancels the
             // alarm (#75).
             scanner.scan()
@@ -291,24 +267,13 @@ class OnboardingViewModel @Inject constructor(
      * returned to, which [OnboardingPlan.canGoBack] already refuses.
      */
     fun goBack() {
-        viewModelScope.launch {
-            when (plan.value?.previous) {
-                OnboardingStep.HiddenCalendars -> prefs.setOnboardingHiddenCalendarsDone(false)
-                OnboardingStep.Calendars -> prefs.setOnboardingCalendarsDone(false)
-                OnboardingStep.Reminders -> prefs.setReminderOnboardingDone(false)
-                OnboardingStep.Backup -> prefs.setOnboardingBackupDone(false)
-                OnboardingStep.View -> prefs.setOnboardingViewDone(false)
-                OnboardingStep.MonthStyle -> prefs.setOnboardingMonthStyleDone(false)
-                OnboardingStep.Visibility -> prefs.setOnboardingVisibilityDone(false)
-                OnboardingStep.Done -> prefs.setOnboardingDoneShown(false)
-                OnboardingStep.Permission, null -> Unit
-            }
-        }
+        val previous = plan.value?.previous ?: return
+        viewModelScope.launch { prefs.setOnboardingDone(previous, done = false) }
     }
 
     /** Close the backup step without setting anything up. */
     fun skipBackup() {
-        viewModelScope.launch { prefs.setOnboardingBackupDone() }
+        viewModelScope.launch { prefs.setOnboardingDone(OnboardingStep.Backup) }
     }
 
     /**
@@ -340,7 +305,7 @@ class OnboardingViewModel @Inject constructor(
     /** Close the calendar step once its confirmation has been read. */
     fun finishCalendars() {
         viewModelScope.launch {
-            prefs.setOnboardingCalendarsDone()
+            prefs.setOnboardingDone(OnboardingStep.Calendars)
             _creation.value = null
         }
     }
@@ -355,7 +320,7 @@ class OnboardingViewModel @Inject constructor(
      * choice, and so is going off to set up an account and coming back.
      */
     fun skipCalendars() {
-        viewModelScope.launch { prefs.setOnboardingCalendarsDone() }
+        viewModelScope.launch { prefs.setOnboardingDone(OnboardingStep.Calendars) }
     }
 
     /**
@@ -381,7 +346,7 @@ class OnboardingViewModel @Inject constructor(
             )
             // Immediate feedback: the first backup lands while onboarding runs.
             BackupScheduler.runNow(context)
-            prefs.setOnboardingBackupDone()
+            prefs.setOnboardingDone(OnboardingStep.Backup)
         }
     }
 
@@ -395,11 +360,11 @@ class OnboardingViewModel @Inject constructor(
 
     /** Close a picker step — the choice itself is saved as it is made. */
     fun finishView() {
-        viewModelScope.launch { prefs.setOnboardingViewDone() }
+        viewModelScope.launch { prefs.setOnboardingDone(OnboardingStep.View) }
     }
 
     fun finishMonthStyle() {
-        viewModelScope.launch { prefs.setOnboardingMonthStyleDone() }
+        viewModelScope.launch { prefs.setOnboardingDone(OnboardingStep.MonthStyle) }
     }
 
     /** Switch one listed calendar on or off, from the hidden-calendars step (#287). */
@@ -436,7 +401,7 @@ class OnboardingViewModel @Inject constructor(
     /** Close the hidden-calendars step, switched on or left as they were (#287). */
     fun finishHiddenCalendars() {
         viewModelScope.launch {
-            prefs.setOnboardingHiddenCalendarsDone()
+            prefs.setOnboardingDone(OnboardingStep.HiddenCalendars)
             // The error belongs to the attempt, not to the step: stepping back
             // into it later must not find a refusal nothing has asked for yet.
             _hiddenWriteFailed.value = false
@@ -451,7 +416,7 @@ class OnboardingViewModel @Inject constructor(
     /** Acknowledge the calendar-visibility notice (#75). */
     fun finishVisibility() {
         viewModelScope.launch {
-            prefs.setOnboardingVisibilityDone()
+            prefs.setOnboardingDone(OnboardingStep.Visibility)
             // Retiring the notice drops its step, so it waits until nothing
             // follows — the count must not fall on the way to a later screen.
             if (plan.value?.steps?.last() == OnboardingStep.Visibility) retireVisibilityNotice()
@@ -488,36 +453,12 @@ class OnboardingViewModel @Inject constructor(
     }
 }
 
-/** The stored answers the plan is derived from. */
-private data class OnboardingFlags(
-    val remindersDone: Boolean,
-    val wizardArmed: Boolean,
-    val backupDone: Boolean,
-    val viewDone: Boolean,
-    val monthStyleDone: Boolean,
-)
-
 /** How the calendar step's create attempt ended (#287). */
 sealed interface CalendarCreation {
     data class Created(val name: String) : CalendarCreation
     data object Failed : CalendarCreation
 }
 
-/** Both calendar steps' inputs (#287). */
-private data class CalendarsFlags(
-    val applies: Boolean?,
-    val done: Boolean,
-    val hiddenApplies: Boolean?,
-    val hiddenDone: Boolean,
-)
-
-/** The tail of the flow: the visibility notice and the closing screen. */
-private data class ClosingFlags(
-    val visibilityArmed: Boolean,
-    val visibilityDone: Boolean,
-    val doneShown: Boolean,
-)
-
 /** What the view step starts from, and renders its previews with. */
 data class ViewChoice(
     val defaultView: CalendarView,

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/PermissionScreen.kt

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.onboarding
 
 import de.jeanlucmakiola.floret.components.BenefitRow
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -13,28 +14,20 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.layout.width
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowForward
 import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material.icons.filled.Lock
-import androidx.compose.material3.Button
-import androidx.compose.material3.ButtonDefaults
-import androidx.compose.material3.Icon
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
-import androidx.hilt.navigation.compose.hiltViewModel
-import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
 
 private val CALENDAR_PERMISSIONS = arrayOf(
@@ -47,9 +40,8 @@ fun PermissionScreen(
     onGranted: () -> Unit,
     modifier: Modifier = Modifier,
     progress: (@Composable () -> Unit)? = null,
-    viewModel: PermissionViewModel = hiltViewModel(),
 ) {
-    val state by viewModel.state.collectAsStateWithLifecycle()
+    var denied by rememberSaveable { mutableStateOf(false) }
 
     // READ and WRITE are requested together (one system dialog — same
     // permission group), but only READ gates the app: declining write keeps
@@ -58,33 +50,27 @@ fun PermissionScreen(
         contract = ActivityResultContracts.RequestMultiplePermissions(),
     ) { results ->
         if (results[Manifest.permission.READ_CALENDAR] == true) {
-            viewModel.onGranted()
+            onGranted()
         } else {
-            viewModel.onDenied()
+            denied = true
         }
     }
 
-    LaunchedEffect(state) {
-        if (state == PermissionUiState.Granted) onGranted()
-    }
-
-    when (state) {
-        is PermissionUiState.Rationale -> RationaleContent(
-            onRequest = { launcher.launch(CALENDAR_PERMISSIONS) },
-            progress = progress,
-            modifier = modifier,
-        )
-        is PermissionUiState.Denied -> DeniedContent(
+    if (denied) {
+        DeniedContent(
             onRetry = {
-                viewModel.onRetry()
+                denied = false
                 launcher.launch(CALENDAR_PERMISSIONS)
             },
             progress = progress,
             modifier = modifier,
         )
-        is PermissionUiState.Granted -> {
-            // Transient — LaunchedEffect above fires and parent replaces us.
-        }
+    } else {
+        RationaleContent(
+            onRequest = { launcher.launch(CALENDAR_PERMISSIONS) },
+            progress = progress,
+            modifier = modifier,
+        )
     }
 }
 
@@ -100,37 +86,15 @@ private fun RationaleContent(
         topSpacing = OnboardingSpace.lg,
         hero = { BrandHero() },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.permission_request_button),
                 onClick = onRequest,
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-                contentPadding = ButtonDefaults.ButtonWithIconContentPadding,
-            ) {
-                Text(
-                    text = stringResource(R.string.permission_request_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-                Spacer(Modifier.width(OnboardingSpace.xs))
-                Icon(
-                    imageVector = Icons.AutoMirrored.Filled.ArrowForward,
-                    contentDescription = null,
-                    modifier = Modifier.size(20.dp),
-                )
-            }
+                trailingIcon = Icons.AutoMirrored.Filled.ArrowForward,
+            )
         },
+        headline = stringResource(R.string.permission_rationale_title),
+        supporting = stringResource(R.string.permission_rationale_body),
     ) {
-        Text(
-            text = stringResource(R.string.permission_rationale_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.permission_rationale_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-
         Spacer(Modifier.height(OnboardingSpace.lg))
 
         BenefitRow(
@@ -159,7 +123,8 @@ private fun DeniedContent(
         progress = progress,
         hero = { BrandHero(HeroBadge.Denied) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.permission_open_settings_button),
                 onClick = {
                     val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS).apply {
                         data = Uri.fromParts("package", context.packageName, null)
@@ -167,13 +132,7 @@ private fun DeniedContent(
                     }
                     context.startActivity(intent)
                 },
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.permission_open_settings_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
             TextButton(
                 onClick = onRetry,
                 modifier = Modifier.fillMaxWidth(),
@@ -181,18 +140,7 @@ private fun DeniedContent(
                 Text(stringResource(R.string.permission_retry_button))
             }
         },
-    ) {
-        Text(
-            text = stringResource(R.string.permission_denied_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.permission_denied_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-    }
+        headline = stringResource(R.string.permission_denied_title),
+        supporting = stringResource(R.string.permission_denied_body),
+    )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/PermissionUiState.kt

@@ -1,7 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.onboarding
-
-sealed interface PermissionUiState {
-    data object Rationale : PermissionUiState
-    data object Denied : PermissionUiState
-    data object Granted : PermissionUiState
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/PermissionViewModel.kt

@@ -1,29 +0,0 @@
-package de.jeanlucmakiola.calendula.ui.onboarding
-
-import androidx.lifecycle.ViewModel
-import dagger.hilt.android.lifecycle.HiltViewModel
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.asStateFlow
-import javax.inject.Inject
-
-@HiltViewModel
-class PermissionViewModel @Inject constructor() : ViewModel() {
-
-    private val _state = MutableStateFlow<PermissionUiState>(PermissionUiState.Rationale)
-    val state: StateFlow<PermissionUiState> = _state.asStateFlow()
-
-    // The visibility reconcile a grant owes (#75) hangs off RootScreen, which
-    // also catches grants made outside the app.
-    fun onGranted() {
-        _state.value = PermissionUiState.Granted
-    }
-
-    fun onDenied() {
-        _state.value = PermissionUiState.Denied
-    }
-
-    fun onRetry() {
-        _state.value = PermissionUiState.Rationale
-    }
-}

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/ReminderStep.kt

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.calendula.ui.onboarding
 
 import de.jeanlucmakiola.floret.components.BenefitRow
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -14,15 +15,11 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.NotificationsActive
 import androidx.compose.material.icons.filled.ContentCopy
-import androidx.compose.material3.Button
-import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
 
 /**
@@ -53,7 +50,8 @@ fun ReminderStep(
         topSpacing = OnboardingSpace.lg,
         hero = { IconHero(Icons.Filled.NotificationsActive) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.reminder_onboarding_enable_button),
                 onClick = {
                     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
                         launcher.launch(Manifest.permission.POST_NOTIFICATIONS)
@@ -61,13 +59,7 @@ fun ReminderStep(
                         onFinished(true)
                     }
                 },
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.reminder_onboarding_enable_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
             TextButton(
                 onClick = { onFinished(false) },
                 modifier = Modifier.fillMaxWidth(),
@@ -75,20 +67,9 @@ fun ReminderStep(
                 Text(stringResource(R.string.reminder_onboarding_skip_button))
             }
         },
+        headline = stringResource(R.string.reminder_onboarding_title),
+        supporting = stringResource(R.string.reminder_onboarding_body),
     ) {
-        Text(
-            text = stringResource(R.string.reminder_onboarding_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.reminder_onboarding_body),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-
         Spacer(Modifier.height(OnboardingSpace.lg))
 
         BenefitRow(

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/ViewStep.kt

@@ -19,8 +19,6 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaViewPreview
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.LocalMultiDayCount
-import de.jeanlucmakiola.calendula.ui.common.PickerDescription
-import de.jeanlucmakiola.calendula.ui.common.ViewPreviewFrame
 import de.jeanlucmakiola.calendula.ui.common.icon
 import de.jeanlucmakiola.calendula.ui.common.label
 import de.jeanlucmakiola.calendula.ui.month.MonthStylePreview
@@ -28,11 +26,12 @@ import de.jeanlucmakiola.calendula.ui.month.MonthViewStyle
 import de.jeanlucmakiola.calendula.ui.month.descriptionRes
 import de.jeanlucmakiola.calendula.ui.month.labelRes
 import de.jeanlucmakiola.calendula.ui.week.WeekViewPreview
+import de.jeanlucmakiola.floret.components.GroupedHint
 import de.jeanlucmakiola.floret.components.GroupedListInset
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 import de.jeanlucmakiola.floret.components.GroupedRow
-import de.jeanlucmakiola.floret.components.SelectedCheck
+import de.jeanlucmakiola.floret.components.ViewPreviewFrame
 import de.jeanlucmakiola.floret.components.positionOf
 import de.jeanlucmakiola.floret.locale.currentLocale
 
@@ -77,11 +76,10 @@ internal fun ViewStep(
             }
         }
         IMPLEMENTED_VIEWS.forEachIndexed { index, view ->
-            val isSelected = view == choice.defaultView
             GroupedRow(
                 title = view.label(),
                 position = positionOf(index, IMPLEMENTED_VIEWS.size),
-                selected = isSelected,
+                checked = view == choice.defaultView,
                 leading = {
                     Icon(
                         imageVector = view.icon,
@@ -89,11 +87,6 @@ internal fun ViewStep(
                         tint = MaterialTheme.colorScheme.onSurfaceVariant,
                     )
                 },
-                trailing = if (isSelected) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
                 onClick = { onSelect(view) },
             )
         }
@@ -127,18 +120,12 @@ internal fun MonthStyleStep(
         StepPreview(selected = choice.monthViewStyle) { style ->
             MonthStylePreview(style = style, weekStart = weekStart, height = PREVIEW_HEIGHT)
         }
-        PickerDescription(stringResource(choice.monthViewStyle.descriptionRes))
+        GroupedHint(stringResource(choice.monthViewStyle.descriptionRes), verticalPadding = 8.dp)
         options.forEachIndexed { index, style ->
-            val isSelected = style == choice.monthViewStyle
             GroupedRow(
                 title = stringResource(style.labelRes),
                 position = positionOf(index, options.size),
-                selected = isSelected,
-                trailing = if (isSelected) {
-                    { SelectedCheck() }
-                } else {
-                    null
-                },
+                checked = style == choice.monthViewStyle,
                 onClick = { onSelect(style) },
             )
         }

app/src/main/java/de/jeanlucmakiola/calendula/ui/onboarding/VisibilityStep.kt

@@ -1,19 +1,12 @@
 package de.jeanlucmakiola.calendula.ui.onboarding
 
-import androidx.compose.foundation.layout.Spacer
-import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.VisibilityOff
-import androidx.compose.material3.Button
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
-import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.calendula.R
+import de.jeanlucmakiola.floret.components.OnboardingPrimaryButton
 import de.jeanlucmakiola.floret.components.OnboardingScaffold
 import de.jeanlucmakiola.floret.components.OnboardingSpace
 
@@ -38,28 +31,12 @@ internal fun VisibilityStep(
         topSpacing = OnboardingSpace.lg,
         hero = { IconHero(Icons.Filled.VisibilityOff) },
         actions = {
-            Button(
+            OnboardingPrimaryButton(
+                text = stringResource(R.string.onboarding_visibility_button),
                 onClick = onFinished,
-                modifier = Modifier.fillMaxWidth().height(56.dp),
-            ) {
-                Text(
-                    text = stringResource(R.string.onboarding_visibility_button),
-                    style = MaterialTheme.typography.titleMedium,
-                )
-            }
+            )
         },
-    ) {
-        Text(
-            text = stringResource(R.string.calendars_visibility_notice_title),
-            style = MaterialTheme.typography.headlineMedium,
-            textAlign = TextAlign.Center,
-        )
-        Spacer(Modifier.height(12.dp))
-        Text(
-            text = stringResource(R.string.calendars_visibility_notice_message),
-            style = MaterialTheme.typography.bodyLarge,
-            color = MaterialTheme.colorScheme.onSurfaceVariant,
-            textAlign = TextAlign.Center,
-        )
-    }
+        headline = stringResource(R.string.calendars_visibility_notice_title),
+        supporting = stringResource(R.string.calendars_visibility_notice_message),
+    )
 }

app/src/main/java/de/jeanlucmakiola/calendula/ui/search/SearchScreen.kt

@@ -1,7 +1,6 @@
 package de.jeanlucmakiola.calendula.ui.search
 
 import android.Manifest
-import android.content.pm.PackageManager
 import androidx.activity.compose.BackHandler
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
@@ -72,7 +71,6 @@ import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardCapitalization
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
-import androidx.core.content.ContextCompat
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import de.jeanlucmakiola.calendula.R
@@ -82,6 +80,7 @@ import de.jeanlucmakiola.calendula.domain.RecurringWriteScope
 import de.jeanlucmakiola.calendula.domain.SearchHit
 import de.jeanlucmakiola.calendula.domain.SearchMonth
 import de.jeanlucmakiola.calendula.domain.isDeclined
+import de.jeanlucmakiola.floret.android.hasPermission
 import de.jeanlucmakiola.floret.identity.LocalFloretDarkTheme
 import de.jeanlucmakiola.floret.identity.animateItemMotion
 import de.jeanlucmakiola.floret.identity.fadeThrough
@@ -99,7 +98,6 @@ import de.jeanlucmakiola.calendula.ui.common.EventDimAlpha
 import de.jeanlucmakiola.calendula.ui.common.LocalSoftenColors
 import de.jeanlucmakiola.calendula.ui.common.RecurringScopeDialog
 import de.jeanlucmakiola.calendula.ui.common.eventAccent
-import de.jeanlucmakiola.calendula.ui.common.eventFill
 import de.jeanlucmakiola.calendula.domain.spanFirstDay
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.timeOfDayFormatter
@@ -167,10 +165,7 @@ fun SearchScreen(
         pendingWrite = null
     }
     val requireWrite: (() -> Unit) -> Unit = { action ->
-        val granted = ContextCompat.checkSelfPermission(
-            context,
-            Manifest.permission.WRITE_CALENDAR,
-        ) == PackageManager.PERMISSION_GRANTED
+        val granted = context.hasPermission(Manifest.permission.WRITE_CALENDAR)
         if (granted) {
             action()
         } else {