feat(components): let picker content own its scrolling

CollapsingScaffold always wrapped its content in a verticalScroll Column,
which composes every row up front. That suits the short lists these
surfaces normally hold, but it rules out a LazyColumn entirely: nesting a
same-axis scrollable inside it throws, so a caller with a few hundred
options had no way to render them.

Add `scrollable` (default true, so every existing caller is unchanged).
When false the content gets a plain column to fill and brings its own
scrolling container, keeping the insets, IME padding and top-bar collapse
as they were. FullScreenPicker forwards the flag for pickers that need it.

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

CHANGELOG.md

@@ -6,14 +6,57 @@ All notable changes to floret-kit are documented here. The format follows
 floret-kit is consumed **from source** — each app embeds it as a git submodule
 and builds it through a Gradle composite build, pinning a specific commit. There
 are no binary releases; "version" tracks the shared `version` in the root build
-(currently `0.1.0`). Entries are grouped by module.
+(currently `0.2.0`). Entries are grouped by module.
 
 ## [Unreleased]
 
+## [0.2.0] - 2026-07-17
+
+### Added
+
+- **`components`** — `CustomAmountEditor`, the amount + unit editor behind an
+  "Custom…" picker option (Calendula's custom snooze duration). Consumed by
+  Calendula since 2.15.0.
+- **`core-locale`** — the locale-aware formatting half of the module, so apps
+  stop hand-rolling `"$day. $month $year"` templates that bake one language's
+  field order (and its separators, and its ordinal dot) into every language they
+  ship:
+  - `localizedDateFormatter(locale, skeleton)` — a `DateTimeFormatter` for a
+    field skeleton ("LLLLy", "dMMMy", "EEEdMMM") laid out in the locale's own
+    order, via Android's best-pattern matching. Drop a field from the skeleton to
+    drop it from the output — the locale still supplies the arrangement.
+  - `currentLocale()` — the display locale, observed from `LocalConfiguration`.
+    Since `AppLanguage.apply()` changes the language inside a running process, a
+    locale captured once goes stale; this keys recomposition to the change.
+
+### Changed
+
+- **`core-locale`** now carries Compose (runtime + ui only) for `currentLocale()`.
+  The module previously declared itself Compose-free; applying a language
+  mid-process is its own API, so the hook that makes the UI notice belongs beside
+  it rather than in a Compose module depending back on this one. `core-crash` is
+  the precedent for a `core-*` module carrying Compose.
+
+### Known gaps
+
+- `core-time`'s `Instant.formatDate()` family now overlaps `core-locale`. Its
+  private `dateNoYearFormatter` strips the year by regex-ing the pattern string,
+  which `localizedDateFormatter(locale, "dMMM")` does properly; and its
+  formatters resolve `Locale.getDefault()` once at class-init ("locale changes
+  within a running process are rare enough to ignore"), which `AppLanguage.apply()`
+  makes untrue. Left alone for now — it is unused by Calendula but Agendula-visible.
+  Reconcile when Agendula next re-pins.
+
 ## [0.1.0] - 2026-07-07
 
 ### Added
 
+- **`core-locale`** (Android library) — per-app language plumbing (`AppLanguage`):
+  read the shipped languages from the app's `res/xml/locales_config.xml`, get/set
+  the applied language via `AppCompatDelegate`, render each language's autonym.
+  The app passes its own `locales_config` resource id; the system-default choice
+  is `null`. _(Shipped in 0.1.0 but omitted from this changelog at the time;
+  recorded here retroactively.)_
 - **`core-time`** (JVM library) — pure-Kotlin date/time helpers, no Android and
   no third-party dependencies:
   - `DayWindow.today()` — local-day boundaries for smart-list logic.

README.md

@@ -36,7 +36,7 @@ See [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) for the full consumption mode
 |--------|------|---------------|
 | `core-time` | JVM | Date/time helpers: `DayWindow` local-day windows, locale/zone-aware `Instant` formatting, `TimeBridge` (millis ↔ `Instant`). No Android, no deps. |
 | `core-reminders` | JVM | Reminder-lead plumbing: the lead-time unit model (`ReminderUnit`, `decomposeReminderMinutes`), the per-target override model (`ReminderOverride` + `reminderLeadFor` / `applyReminderOverride`) and the stored-format codec (`ReminderOverrideCodec`, separators configurable per app). Each app layers its own DataStore + string labels on top. |
-| `core-locale` | Android | Per-app language plumbing (`AppLanguage`): read the shipped languages from the app's `res/xml/locales_config.xml`, get/set the applied language via `AppCompatDelegate`, render each language's autonym. The app passes its own `locales_config`; appcompat only, no Compose. |
+| `core-locale` | Android | Everything "what language are we in". Per-app language plumbing (`AppLanguage`): read the shipped languages from the app's `res/xml/locales_config.xml`, get/set the applied language via `AppCompatDelegate`, render each language's autonym. Plus `currentLocale()` (observes the applied language from Compose) and `localizedDateFormatter(locale, skeleton)` (lays a field skeleton out in the locale's own order). The app passes its own `locales_config`. |
 | `core-crash` | Android | Privacy-respecting on-device crash capture + report dialog + issue-tracker hand-off. Parameterized per app via `CrashConfig`. |
 | `identity` | Android | The M3 Expressive theme factory `FloretExpressiveTheme(…)`, `rememberNavSlideSpec()`, the content transitions (`expandEnter`/`collapseExit`/`itemEnter`/…) and the `predictiveBack` peek. Each app supplies its own seed/palette. |
 | `components` | Android | Shared Compose vocabulary + recipes: `GroupedSurface`/`GroupedRow`, `InlineTextField`, `OptionCard`, `CollapsingScaffold`, `OptionPicker`, `ReorderableColumn`, `DebugRibbon`, `pastelize()`, `DialogControls`, `OnboardingScaffold`, `OptionalFormSection`, `AboutCard`, `LanguagePickerRow`. |

components/src/main/kotlin/de/jeanlucmakiola/floret/components/CollapsingScaffold.kt

@@ -46,6 +46,16 @@ import de.jeanlucmakiola.floret.identity.predictiveBack
  * unchanged: [actions] adds trailing app-bar items; [snackbarHost] hosts
  * transient messages; [predictiveBack] (off by default) wires the gesture
  * preview to [onBack] for full-screen surfaces that want it.
+ *
+ * Set [scrollable] to false when [content] brings its own scrolling container.
+ * The default column scrolls as a whole, which composes every row up front —
+ * fine for the short lists these surfaces normally hold, but a list long enough
+ * to need a [androidx.compose.foundation.lazy.LazyColumn] can neither nest one
+ * inside it (same-axis scrolling throws) nor afford the eager pass. Opting out
+ * hands [content] a plain, unscrolled column to fill instead; the insets, IME
+ * padding and bar behaviour are unchanged, so a lazy list simply takes over the
+ * scrolling and gets the top bar's collapse for free through the shared
+ * nested-scroll connection.
  */
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -55,6 +65,7 @@ fun CollapsingScaffold(
     modifier: Modifier = Modifier,
     largeTopBar: Boolean = true,
     predictiveBack: Boolean = false,
+    scrollable: Boolean = true,
     actions: @Composable RowScope.() -> Unit = {},
     snackbarHost: @Composable () -> Unit = {},
     content: @Composable ColumnScope.() -> Unit,
@@ -112,8 +123,19 @@ fun CollapsingScaffold(
                 .fillMaxSize()
                 .background(MaterialTheme.colorScheme.surface)
                 .imePadding()
-                .verticalScroll(rememberScrollState())
-                .padding(top = 8.dp, bottom = 24.dp),
+                .then(
+                    if (scrollable) {
+                        Modifier
+                            .verticalScroll(rememberScrollState())
+                            .padding(top = 8.dp, bottom = 24.dp)
+                    } else {
+                        // The content scrolls itself, so it also owns the edge
+                        // spacing — a lazy list wants it as contentPadding, or
+                        // the first and last rows clip instead of scrolling
+                        // under the bars.
+                        Modifier
+                    },
+                ),
             content = content,
         )
     }

components/src/main/kotlin/de/jeanlucmakiola/floret/components/OptionPicker.kt

@@ -20,12 +20,17 @@ import androidx.compose.ui.window.DialogWindowProvider
  * width without a tall header — it's a short selection list, so the large
  * collapsing header would only be empty space to scroll past. [content] places
  * the connected grouped rows; selecting one calls [onDismiss].
+ *
+ * [scrollable] forwards to [CollapsingScaffold]: leave it on unless [content]
+ * scrolls itself, which a picker only needs for an option list long enough to
+ * warrant a lazy container.
  */
 @Composable
 fun FullScreenPicker(
     title: String,
     onDismiss: () -> Unit,
     predictiveBack: Boolean = false,
+    scrollable: Boolean = true,
     actions: @Composable RowScope.() -> Unit = {},
     content: @Composable ColumnScope.() -> Unit,
 ) {
@@ -50,6 +55,7 @@ fun FullScreenPicker(
             onBack = onDismiss,
             largeTopBar = false,
             predictiveBack = predictiveBack,
+            scrollable = scrollable,
             actions = actions,
             content = content,
         )

core-locale/build.gradle.kts

@@ -1,10 +1,20 @@
-// core-locale — per-app language plumbing shared across the family: read the
-// shipped languages from res/xml/locales_config.xml, get/set the applied
-// language via AppCompatDelegate, and render each language's autonym. App-
-// agnostic — the consuming app passes its own locales_config resource id; no
-// Compose, no DataStore.
+// core-locale — everything "what language are we in", shared across the family:
+// read the shipped languages from res/xml/locales_config.xml, get/set the applied
+// language via AppCompatDelegate, render each language's autonym, observe the
+// current locale from Compose, and format dates in that locale's own field order.
+// App-agnostic — the consuming app passes its own locales_config resource id; no
+// DataStore.
+//
+// Compose is here for currentLocale() alone: applying a language mid-process is
+// this module's own API, so the hook that makes the UI notice belongs beside it
+// rather than in a Compose module that would have to depend back on this one.
+// (core-crash is the precedent for a core-* module carrying Compose.) Deliberately
+// lean: runtime + ui only, no material3, no foundation.
 plugins {
+    // AGP 9.x provides built-in Kotlin compilation, so only the Compose plugin is
+    // applied alongside the Android library plugin.
     alias(libs.plugins.android.library)
+    alias(libs.plugins.kotlin.compose)
 }
 
 android {
@@ -20,6 +30,10 @@ android {
         targetCompatibility = JavaVersion.VERSION_17
     }
 
+    buildFeatures {
+        compose = true
+    }
+
     testOptions {
         unitTests {
             all { it.useJUnitPlatform() }
@@ -39,6 +53,16 @@ dependencies {
     // annotation (XmlRes) transitives.
     implementation(libs.androidx.appcompat)
 
+    // ConfigurationCompat for currentLocale(). Reachable transitively via
+    // appcompat, but declared because this module uses it directly.
+    implementation(libs.androidx.core.ktx)
+
+    // currentLocale() only needs the runtime (@Composable, remember) and ui
+    // (LocalConfiguration) — api() so consumers can use the returned Locale in
+    // their own composables without re-declaring Compose themselves.
+    api(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.ui)
+
     testImplementation(libs.junit.jupiter.api)
     testRuntimeOnly(libs.junit.jupiter.engine)
     testRuntimeOnly(libs.junit.platform.launcher)

core-locale/src/main/kotlin/de/jeanlucmakiola/floret/locale/DateFormatting.kt

@@ -0,0 +1,33 @@
+package de.jeanlucmakiola.floret.locale
+
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+
+/**
+ * A [DateTimeFormatter] for [skeleton]'s fields laid out in [locale]'s own order,
+ * via Android's best-pattern matching.
+ *
+ * A skeleton lists the *fields* you want, not their arrangement: "dMMMy" asks for
+ * day, abbreviated month and year, and the locale decides that en-US renders
+ * "Jul 17, 2026" while de-DE renders "17. Juli 2026". Hand-rolled templates like
+ * `"$day. $month $year"` can't do this — they bake one locale's order (and its
+ * separators, and its ordinal dot) into every language the app ships.
+ *
+ * Drop a field to drop it from the output: "dMMM" is the same date without the
+ * year, still in the locale's order. Prefer that over post-processing a longer
+ * pattern, which cannot know which separators belonged to the removed field.
+ *
+ * Common skeletons: "LLLLy" (standalone month + year), "dMMMy" (day, month, year),
+ * "EEEdMMM" (weekday too). [locale] should come from [currentLocale] in Compose,
+ * so formatting follows an in-process language change.
+ *
+ * NB: this delegates to `android.text.format.DateFormat`, so it needs a real
+ * Android runtime — under unit tests with `isReturnDefaultValues` it yields no
+ * pattern. Test the skeleton *choice* in your own code; the layout itself is ICU's
+ * job and is not worth mocking.
+ */
+fun localizedDateFormatter(locale: Locale, skeleton: String): DateTimeFormatter =
+    DateTimeFormatter.ofPattern(
+        android.text.format.DateFormat.getBestDateTimePattern(locale, skeleton),
+        locale,
+    )

core-locale/src/main/kotlin/de/jeanlucmakiola/floret/locale/LocaleCompose.kt

@@ -0,0 +1,26 @@
+package de.jeanlucmakiola.floret.locale
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalConfiguration
+import androidx.core.os.ConfigurationCompat
+import java.util.Locale
+
+/**
+ * The current display [Locale], read observably from [LocalConfiguration].
+ *
+ * Use this rather than [Locale.getDefault] anywhere a composable formats a date,
+ * a name or a number. [AppLanguage.apply] changes the language inside a running
+ * process, so a locale captured once — in a `val`, a top-level formatter, or a
+ * `remember {}` with no key — goes stale and keeps rendering the old language.
+ * Reading through [LocalConfiguration] keys recomposition to the configuration,
+ * so the UI follows the switch. (Android lint flags the alternative as
+ * NonObservableLocale.)
+ */
+@Composable
+fun currentLocale(): Locale {
+    val configuration = LocalConfiguration.current
+    return remember(configuration) {
+        ConfigurationCompat.getLocales(configuration).get(0) ?: Locale.getDefault()
+    }
+}

docs/ROADMAP.md

@@ -13,6 +13,7 @@ divergent or app-specific code where it lives.
 |---|---|---|
 | `core-time` | JVM | Agendula (and Calendula's pending branch) |
 | `core-reminders` | JVM | Agendula (and Calendula's pending branch) |
+| `core-locale` | Android | Agendula, Calendula |
 | `core-crash` | Android | Agendula |
 | `identity` | Android | Agendula |
 | `components` | Android | Agendula |