fix(intents): register calendar intent filters so Calendula can be the default calendar (#9)

Calendula didn't declare the intent filters launchers and the system use for
calendar actions, so it never appeared in the "default calendar app" chooser —
on every platform, not just GrapheneOS (issue #9). Android exposes no API for an
app to set itself default, so registering these filters is the only way users can
pick it from the system picker.

Adds to MainActivity:
- MAIN + APP_CALENDAR — the "open the calendar app" action the OS/launchers use.
- VIEW on content://com.android.calendar/time/<epochMillis> and the time/epoch
  mime type — a launcher/clock date tap. The provider's time Uri is parsed into a
  LocalDate and opened on the day view, rooted over the default home view (a new
  sourceless WidgetNavRequest.OpenDate). The .ics import path now ignores the
  calendar provider host so a date tap isn't mistaken for a file to import.

Bumps to 2.11.1.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.11.1] — 2026-06-28
+
+### Fixed
+- Calendula can now be set as your default calendar app. It registers the
+  calendar-app intent filters the system uses, so it appears in the chooser when
+  you tap a date in a launcher or clock — and opening one takes you straight to
+  that day. Android has no way for an app to make itself the default, so you pick
+  it once from the system picker. Thanks to @abrossimow for the report ([#9]).
+
 ## [2.11.0] — 2026-06-27
 
 ### Added
@@ -30,10 +39,32 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   top naming the exact dates in view, with a button to switch the range just for
   the current session (it resets when you reopen the app); the bar can be turned
   off. Thanks to @zmaherdev for the suggestion ([#4]).
+- Automatic backup of local calendars. A new **Automatic backup** option
+  (Settings → Calendars → Backup) periodically exports your local calendars to an
+  `.ics` file in a folder you choose, on an interval you set (from 30 minutes up).
+  Useful for file-based syncing such as Syncthing, or simply as a safety net — it
+  is a one-way export and never touches your synced accounts. Thanks to @shield
+  for the discussion that inspired it ([#7], [#8]).
+- Field icons in the event-form settings. Each optional-field toggle (Settings →
+  Event form) now shows the same icon the field uses in the new-event form, so
+  the list is easier to scan.
+- Help translate Calendula. A **Help translate** link at the top of **Settings →
+  App language** opens the project's Weblate, where you can add or improve a
+  language in your browser — no coding needed. Contributions in any language are
+  welcome.
 
 ### Changed
 - Tidied **Settings → Appearance** into clearer groups (theme & colour, calendar,
   agenda), and the agenda's empty state now reads "You're all caught up".
+- Reworked **Settings → Calendars**. Local and synced calendars are now grouped
+  into collapsible, source-branded cards — each account shows its app's icon —
+  with a per-account menu to enable or disable all of its calendars at once or
+  open the account in its source app.
+- Reorganised **Settings → Notifications**: reliable-delivery and snooze settings
+  moved up with the other global reminder options, and the per-calendar reminder
+  overrides now fold into a single expandable section.
+- Moved **Add Quick Settings tile** out of the event-form section to its own
+  top-level entry in Settings.
 
 ## [2.10.0] — 2026-06-25
 
@@ -661,3 +692,6 @@ automatically, with zero telemetry and no internet permission.
 [#4]: https://codeberg.org/jlmakiola/calendula/issues/4
 [#5]: https://codeberg.org/jlmakiola/calendula/issues/5
 [#6]: https://codeberg.org/jlmakiola/calendula/issues/6
+[#7]: https://codeberg.org/jlmakiola/calendula/issues/7
+[#8]: https://codeberg.org/jlmakiola/calendula/issues/8
+[#9]: https://codeberg.org/jlmakiola/calendula/issues/9

README.md

@@ -68,7 +68,8 @@ database, no sync stack reinvented.
 
 - Real Material 3 Expressive throughout — dynamic color (Android 12+),
   expressive motion and shapes, light/dark theme
-- German and English UI, per-app language setting
+- German and English UI, per-app language setting — and [open to community
+  translations](#-translations)
 - **Zero telemetry, zero analytics, no internet permission** — your data
   never leaves the device
 
@@ -108,6 +109,17 @@ without reinstalling. Or build from source — see below.
 - **[Architecture](docs/ARCHITECTURE.md)** — the layered design and key pipelines
 - **[Roadmap](.planning/ROADMAP.md)** — what's shipped and what's next
 
+## 🌍 Translations
+
+Calendula ships in German and English, and you're warmly invited to add your
+language. Translations are managed on a self-hosted **Weblate**:
+
+**→ [Help translate Calendula](https://weblate.dev.jeanlucmakiola.de/engage/calendula/)**
+
+No coding needed — register on the Weblate server, pick (or request) a language,
+and translate the strings in your browser. You can also reach this link in the
+app from the top of **Settings → App language**.
+
 ## 📜 License
 
 [MIT](LICENSE) — Jean-Luc Makiola, 2026

app/build.gradle.kts

@@ -28,8 +28,8 @@ android {
         // which builds this version and then creates the matching vX.Y.Z tag +
         // release itself (versionCode is pinned to MAJOR*10000 + MINOR*100 +
         // PATCH from versionName, e.g. 2.7.2 -> 20702). See docs/RELEASING.md.
-        versionCode = 21100
+        versionCode = 21101
-        versionName = "2.11.0"
+        versionName = "2.11.1"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }

app/src/main/AndroidManifest.xml

@@ -59,6 +59,35 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
 
+            <!-- Be selectable as the system calendar app. Android has no API for
+                 an app to make itself the default, so registering the filters
+                 launchers and the OS use is what lets the user pick Calendula
+                 from the system chooser when a date action fires (issue #9).
+                 APP_CALENDAR is the "open the calendar app" action; the VIEW
+                 filters below catch a tapped date. -->
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.APP_CALENDAR" />
+            </intent-filter>
+            <!-- A launcher/clock date tap fires ACTION_VIEW on the provider's
+                 time Uri (content://com.android.calendar/time/<epochMillis>);
+                 some surfaces use the time/epoch mime type. We open the day view
+                 on that date (MainActivity.calendarTimeDateOrNull). -->
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data
+                    android:scheme="content"
+                    android:host="com.android.calendar"
+                    android:pathPrefix="/time" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="time/epoch" />
+            </intent-filter>
+
             <!-- Open a .ics file (file manager / email attachment / browser). -->
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />

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

@@ -1,8 +1,16 @@
 package de.jeanlucmakiola.calendula
 
 import android.app.Application
+import dagger.hilt.android.EntryPointAccessors
 import dagger.hilt.android.HiltAndroidApp
+import de.jeanlucmakiola.calendula.data.backup.BackupScheduler
+import de.jeanlucmakiola.calendula.data.backup.BackupWorker
 import de.jeanlucmakiola.calendula.data.crash.CrashReporter
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
 
 /**
  * Application entry point. Registered as android:name=".CalendulaApp"
@@ -16,5 +24,24 @@ class CalendulaApp : Application() {
         // Install first thing so startup crashes are captured too (privacy-
         // respecting, on-device; the user submits the report by hand).
         CrashReporter.install(this)
+        reconcileAutoBackup()
+    }
+
+    /**
+     * Bring the scheduled auto-backup work back in line with the saved settings
+     * on every launch — re-arms it after a reinstall and, crucially, cancels any
+     * orphaned work once backup has been turned off.
+     */
+    private fun reconcileAutoBackup() {
+        val deps = EntryPointAccessors.fromApplication(this, BackupWorker.Deps::class.java)
+        CoroutineScope(SupervisorJob() + Dispatchers.Default).launch {
+            val prefs = deps.settingsPrefs()
+            BackupScheduler.apply(
+                context = this@CalendulaApp,
+                enabled = prefs.autoBackupEnabled.first(),
+                intervalMinutes = prefs.autoBackupIntervalMinutes.first(),
+                hasFolder = prefs.autoBackupFolderUri.first() != null,
+            )
+        }
     }
 }

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

@@ -35,6 +35,9 @@ import de.jeanlucmakiola.calendula.ui.crash.submitCrashReport
 import de.jeanlucmakiola.calendula.ui.settings.SettingsViewModel
 import de.jeanlucmakiola.calendula.ui.theme.CalendulaTheme
 import kotlinx.datetime.LocalDate
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Instant
 
 @AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
@@ -156,10 +159,33 @@ class MainActivity : AppCompatActivity() {
             Intent.ACTION_SEND -> IntentCompat.getParcelableExtra(this, Intent.EXTRA_STREAM, Uri::class.java)
             else -> null
         } ?: return null
+        // The calendar "view time" Uri (a date tap) is also ACTION_VIEW/content;
+        // it's a navigation, not a file to import, so [navRequestOrNull] owns it.
+        if (uri.host == CALENDAR_PROVIDER_HOST) return null
         return uri.takeIf { it.scheme == "content" || it.scheme == "file" }
     }
 
+    /**
+     * The date a launcher/clock date tap points at, parsed from the AOSP calendar
+     * "view time" intent: ACTION_VIEW on `content://com.android.calendar/time/
+     * <epochMillis>`. Null for any other intent. The matching manifest filter is
+     * what lets users pick Calendula from the system calendar chooser (issue #9).
+     */
+    private fun Intent.calendarTimeDateOrNull(): LocalDate? {
+        if (action != Intent.ACTION_VIEW) return null
+        val uri = data ?: return null
+        if (uri.host != CALENDAR_PROVIDER_HOST) return null
+        val segments = uri.pathSegments
+        if (segments.firstOrNull() != "time") return null
+        val millis = segments.getOrNull(1)?.toLongOrNull() ?: return null
+        return Instant.fromEpochMilliseconds(millis)
+            .toLocalDateTime(TimeZone.currentSystemDefault()).date
+    }
+
     private fun Intent.navRequestOrNull(): WidgetNavRequest? {
+        // An external date tap (launcher/clock) has no widget source, so it opens
+        // the day view rooted over the default home view (OpenDate source = null).
+        calendarTimeDateOrNull()?.let { return WidgetNavRequest.OpenDate(it.toString(), source = null) }
         val source = sourceViewOrNull()
         val eventId = getLongExtra(EXTRA_EVENT_ID, -1L)
         return when {
@@ -201,6 +227,10 @@ class MainActivity : AppCompatActivity() {
     }
 
     companion object {
+        // The calendar provider's authority/host. A date tap arrives as
+        // ACTION_VIEW on content://com.android.calendar/time/<epochMillis>.
+        private const val CALENDAR_PROVIDER_HOST = "com.android.calendar"
+
         private const val EXTRA_EVENT_ID = "de.jeanlucmakiola.calendula.extra.EVENT_ID"
         private const val EXTRA_BEGIN_MILLIS = "de.jeanlucmakiola.calendula.extra.BEGIN"
         private const val EXTRA_END_MILLIS = "de.jeanlucmakiola.calendula.extra.END"

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

@@ -55,6 +55,9 @@ object BackupScheduler {
         val workManager = WorkManager.getInstance(context)
         if (!enabled || !hasFolder) {
             workManager.cancelUniqueWork(WORK_NAME)
+            // Also cancel any pending immediate run — otherwise a failing run-now
+            // keeps retrying after the user has turned backup off.
+            workManager.cancelUniqueWork(WORK_NAME_NOW)
             return
         }
         // WorkManager's own floor is 15 min; the UI floors the user choice at 30.
@@ -106,6 +109,9 @@ class BackupWorker(
     override suspend fun doWork(): Result {
         val deps = EntryPointAccessors.fromApplication(applicationContext, Deps::class.java)
         val prefs = deps.settingsPrefs()
+        // Respect the toggle even for already-queued work: if backup was turned
+        // off, no-op (and don't retry) so a lingering run can't revive itself.
+        if (!prefs.autoBackupEnabled.first()) return Result.success()
         val folder = prefs.autoBackupFolderUri.first()
             ?: return Result.failure() // nothing to write to — leave scheduling to settings
         val now = System.currentTimeMillis()

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

@@ -196,7 +196,9 @@ fun CalendarHost(
                 dismissCoveringOverlays()
                 createDateIso = null
                 pendingDayIso = req.dateIso
-                viewStack = viewBaseStack(defaultView, req.source).drillToDay()
+                // 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()
             }
             is WidgetNavRequest.OpenEvent -> {

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

@@ -13,8 +13,13 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarView
  * detail-key channel and leave the base view untouched.)
  */
 sealed interface WidgetNavRequest {
-    /** Open the day view anchored on [dateIso] (an ISO `yyyy-MM-dd` date), over [source]. */
+    /**
-    data class OpenDate(val dateIso: String, val source: CalendarView) : WidgetNavRequest
+     * Open the day view anchored on [dateIso] (an ISO `yyyy-MM-dd` date), over
+     * [source]. A null [source] means the request came from outside the app (a
+     * launcher/clock date tap, issue #9) rather than a widget, so it roots over
+     * the default home view instead of a widget's view.
+     */
+    data class OpenDate(val dateIso: String, val source: CalendarView?) : WidgetNavRequest
 
     /** Open one occurrence's detail (an agenda-widget event tap), over [source]. */
     data class OpenEvent(

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

@@ -86,8 +86,10 @@ fun <T> OptionPicker(
     label: @Composable (T) -> String,
     onSelect: (T) -> Unit,
     onDismiss: () -> Unit,
+    header: (@Composable ColumnScope.() -> Unit)? = null,
 ) {
     FullScreenPicker(title = title, onDismiss = onDismiss) {
+        header?.invoke(this)
         options.forEachIndexed { index, option ->
             val isSelected = option == selected
             GroupedRow(

app/src/main/java/de/jeanlucmakiola/calendula/ui/settings/SettingsScreen.kt

@@ -48,6 +48,7 @@ import androidx.compose.material.icons.filled.Gavel
 import androidx.compose.material.icons.filled.Language
 import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.Palette
+import androidx.compose.material.icons.filled.Translate
 import androidx.compose.material.icons.filled.Tune
 import androidx.compose.material3.FilledTonalButton
 import androidx.compose.material3.Icon
@@ -318,6 +319,18 @@ private fun LanguageRow(position: Position) {
                 AppLanguage.apply(it)
             },
             onDismiss = { showDialog = false },
+            // Invite contributions right where users pick their language.
+            header = {
+                val translateUrl = stringResource(R.string.about_translate_url)
+                GroupedRow(
+                    title = stringResource(R.string.settings_translate),
+                    summary = stringResource(R.string.settings_translate_hint),
+                    position = Position.Alone,
+                    leading = { CategoryIcon(Icons.Default.Translate, ChipAccent.Neutral) },
+                    onClick = { openUrl(context, translateUrl) },
+                )
+                Spacer(Modifier.height(16.dp))
+            },
         )
     }
 }

app/src/main/res/values/strings.xml

@@ -330,6 +330,8 @@
     <string name="settings_section_language">Language</string>
     <string name="settings_language">App language</string>
     <string name="settings_language_auto">System default</string>
+    <string name="settings_translate">Help translate</string>
+    <string name="settings_translate_hint">Add or improve a language on Weblate</string>
     <!-- Hub category subtitles -->
     <string name="settings_appearance_subtitle">Theme, default view, week start</string>
     <string name="settings_event_form_subtitle">Default fields for new events</string>
@@ -436,6 +438,7 @@
     <string name="about_source_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/calendula</string>
     <string name="about_license_url" translatable="false">https://gitea.jeanlucmakiola.de/makiolaj/calendula/src/branch/main/LICENSE</string>
     <string name="about_support_url" translatable="false">https://ko-fi.com/jeanlucmakiola</string>
+    <string name="about_translate_url" translatable="false">https://weblate.dev.jeanlucmakiola.de/engage/calendula/</string>
 
     <!-- Crash reporting: a captured report the user can submit, by hand, as a
          Gitea issue (the app sends nothing automatically). -->

fastlane/metadata/android/en-US/changelogs/21100.txt

@@ -21,8 +21,30 @@
   top naming the exact dates in view, with a button to switch the range just for
   the current session (it resets when you reopen the app); the bar can be turned
   off. Thanks to @zmaherdev for the suggestion ([#4]).
+- Automatic backup of local calendars. A new **Automatic backup** option
+  (Settings → Calendars → Backup) periodically exports your local calendars to an
+  `.ics` file in a folder you choose, on an interval you set (from 30 minutes up).
+  Useful for file-based syncing such as Syncthing, or simply as a safety net — it
+  is a one-way export and never touches your synced accounts. Thanks to @shield
+  for the discussion that inspired it ([#7], [#8]).
+- Field icons in the event-form settings. Each optional-field toggle (Settings →
+  Event form) now shows the same icon the field uses in the new-event form, so
+  the list is easier to scan.
+- Help translate Calendula. A **Help translate** link at the top of **Settings →
+  App language** opens the project's Weblate, where you can add or improve a
+  language in your browser — no coding needed. Contributions in any language are
+  welcome.
 
 ### Changed
 - Tidied **Settings → Appearance** into clearer groups (theme & colour, calendar,
   agenda), and the agenda's empty state now reads "You're all caught up".
+- Reworked **Settings → Calendars**. Local and synced calendars are now grouped
+  into collapsible, source-branded cards — each account shows its app's icon —
+  with a per-account menu to enable or disable all of its calendars at once or
+  open the account in its source app.
+- Reorganised **Settings → Notifications**: reliable-delivery and snooze settings
+  moved up with the other global reminder options, and the per-calendar reminder
+  overrides now fold into a single expandable section.
+- Moved **Add Quick Settings tile** out of the event-form section to its own
+  top-level entry in Settings.
 

fastlane/metadata/android/en-US/changelogs/21101.txt

@@ -0,0 +1,6 @@
+### Fixed
+- Calendula can now be set as your default calendar app. It registers the
+  calendar-app intent filters the system uses, so it appears in the chooser when
+  you tap a date in a launcher or clock — and opening one takes you straight to
+  that day. Android has no way for an app to make itself the default, so you pick
+  it once from the system picker. Thanks to @abrossimow for the report ([#9]).