feat(views): customizable quick-switch cycle + drawer order (#24)

Add a "Views" settings section that lets users pick which views the
top-bar quick-switch button cycles through and drag to reorder them,
plus an independent drag-to-reorder for the navigation drawer's view
list. Two separate configs: a view turned off in the quick-switch
cycle is still reachable from the drawer, which always lists every view.

- QuickSwitchConfig (order + enabled set) and a drawer order persisted
  in SettingsPrefs (comma-joined enum names; "!" marks a disabled view).
  Missing views append enabled and unknown names drop, so a future view
  defaults into both lists.
- The pill cycles through the configured enabled views in order; the
  drawer renders CalendarDrawer from the drawer order. Both threaded
  from CalendarHost via CalendarHostViewModel.
- New ReorderableColumn: dependency-free, measurement-driven drag
  reordering for the short grouped-card settings lists (no LazyColumn,
  since settings are a single verticalScroll column). Commits one write
  per gesture.
- The switch needs two targets, so the last two enabled views can't be
  turned off.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

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

@@ -12,6 +12,8 @@ import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.parseAgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.map
 import kotlinx.datetime.DayOfWeek
@@ -202,6 +204,34 @@ class SettingsPrefs @Inject constructor(
         store.edit { it[DEFAULT_VIEW_KEY] = view.name }
     }
 
+    /**
+     * Quick-switch button customisation (#24): the ordered full view list plus
+     * which views are enabled in the cycle. Stored comma-joined by enum name, a
+     * "!" prefix marking a disabled view (e.g. "Month,Week,!Day,Agenda"). Missing
+     * views are appended enabled and unknown names dropped, so a future view
+     * defaults into the cycle. An absent key means [QuickSwitchConfig.Default].
+     */
+    val quickSwitchConfig: Flow<QuickSwitchConfig> = store.data.map { prefs ->
+        parseQuickSwitch(prefs[QUICK_SWITCH_VIEWS_KEY])
+    }
+
+    suspend fun setQuickSwitchConfig(config: QuickSwitchConfig) {
+        store.edit { it[QUICK_SWITCH_VIEWS_KEY] = serializeQuickSwitch(config) }
+    }
+
+    /**
+     * Navigation-drawer view order (#24). Comma-joined enum names; missing views
+     * are appended in default order and unknown names dropped. Absent key means
+     * [IMPLEMENTED_VIEWS] (the historical fixed order).
+     */
+    val drawerViewOrder: Flow<List<CalendarView>> = store.data.map { prefs ->
+        parseViewOrder(prefs[DRAWER_VIEW_ORDER_KEY])
+    }
+
+    suspend fun setDrawerViewOrder(order: List<CalendarView>) {
+        store.edit { it[DRAWER_VIEW_ORDER_KEY] = order.joinToString(",") { view -> view.name } }
+    }
+
     /**
      * Optional event-form fields shown by default (the rest hide behind
      * "more fields"). Stored comma-joined by enum name: an absent key means
@@ -433,6 +463,40 @@ class SettingsPrefs @Inject constructor(
             .toSet()
     }
 
+    /** Parse a plain comma-joined view order, completed to every implemented view. */
+    private fun parseViewOrder(stored: String?): List<CalendarView> =
+        completeViewOrder(
+            stored?.split(',').orEmpty()
+                .mapNotNull { name -> CalendarView.entries.firstOrNull { it.name == name.trim() } },
+        )
+
+    /** Parse the quick-switch config; "!"-prefixed names are disabled. */
+    private fun parseQuickSwitch(stored: String?): QuickSwitchConfig {
+        if (stored == null) return QuickSwitchConfig.Default
+        val parsed = stored.split(',').mapNotNull { raw ->
+            val token = raw.trim()
+            val disabled = token.startsWith("!")
+            val name = if (disabled) token.drop(1) else token
+            CalendarView.entries.firstOrNull { it.name == name }?.let { it to disabled }
+        }
+        val order = completeViewOrder(parsed.map { it.first })
+        // Only views explicitly stored disabled are excluded; anything appended
+        // (a view added in a later release) defaults into the cycle.
+        val disabled = parsed.filter { it.second }.map { it.first }.toSet()
+        return QuickSwitchConfig(order, order.filterNot { it in disabled }.toSet())
+    }
+
+    private fun serializeQuickSwitch(config: QuickSwitchConfig): String =
+        completeViewOrder(config.order).joinToString(",") { view ->
+            if (view in config.enabled) view.name else "!${view.name}"
+        }
+
+    /** Keep the given order (de-duplicated), then append any views it omits. */
+    private fun completeViewOrder(seen: List<CalendarView>): List<CalendarView> {
+        val ordered = seen.distinct()
+        return ordered + IMPLEMENTED_VIEWS.filterNot { it in ordered }
+    }
+
     companion object {
         internal val THEME_MODE_KEY = stringPreferencesKey("theme_mode")
         internal val DYNAMIC_COLOR_KEY = booleanPreferencesKey("dynamic_color")
@@ -445,6 +509,8 @@ class SettingsPrefs @Inject constructor(
         internal val PAST_EVENT_DISPLAY_KEY = stringPreferencesKey("agenda_past_event_display")
         internal val DIM_COMPLETED_EVENTS_KEY = booleanPreferencesKey("dim_completed_events")
         internal val DEFAULT_VIEW_KEY = stringPreferencesKey("default_view")
+        internal val QUICK_SWITCH_VIEWS_KEY = stringPreferencesKey("quick_switch_views")
+        internal val DRAWER_VIEW_ORDER_KEY = stringPreferencesKey("drawer_view_order")
         internal val FORM_FIELDS_KEY = stringPreferencesKey("event_form_default_fields")
         internal val AUTOFOCUS_EVENT_TITLE_KEY = booleanPreferencesKey("autofocus_event_title")
         internal val REMINDERS_ENABLED_KEY = booleanPreferencesKey("reminders_enabled")

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

@@ -79,6 +79,11 @@ fun CalendarHost(
     // correcting it. Brief blank first frame, matching the onboarding gate above.
     val defaultView = viewModel.defaultView.collectAsStateWithLifecycle().value ?: return
 
+    // View customisation (#24): the quick-switch cycle and drawer order. Both have
+    // sensible non-empty initial values, so they're ready before the first frame.
+    val quickSwitchViews = viewModel.quickSwitchViews.collectAsStateWithLifecycle().value
+    val drawerViewOrder = viewModel.drawerViewOrder.collectAsStateWithLifecycle().value
+
     var viewStack by rememberSaveable(stateSaver = viewStackSaver) {
         mutableStateOf(listOf(defaultView))
     }
@@ -260,6 +265,8 @@ fun CalendarHost(
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
                 )
                 CalendarView.Day -> DayScreen(
                     selectedView = currentView,
@@ -269,6 +276,8 @@ fun CalendarHost(
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
                     initialDateIso = pendingDayIso,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
                 )
                 CalendarView.Month -> MonthScreen(
                     selectedView = currentView,
@@ -277,6 +286,8 @@ fun CalendarHost(
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
                 )
                 CalendarView.Agenda -> AgendaScreen(
                     selectedView = currentView,
@@ -285,6 +296,8 @@ fun CalendarHost(
                     onOpenSettings = onOpenSettings,
                     onOpenSearch = onOpenSearch,
                     onCreateEvent = onCreateEvent,
+                    quickSwitchViews = quickSwitchViews,
+                    drawerViewOrder = drawerViewOrder,
                 )
             }
         }

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

@@ -5,8 +5,10 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import de.jeanlucmakiola.calendula.data.prefs.SettingsPrefs
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import javax.inject.Inject
 
@@ -26,4 +28,21 @@ class CalendarHostViewModel @Inject constructor(
         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(
+            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(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000L),
+            initialValue = IMPLEMENTED_VIEWS,
+        )
 }

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

@@ -64,6 +64,7 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
 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.GroupedRow
 import de.jeanlucmakiola.calendula.ui.common.Position
@@ -96,6 +97,8 @@ fun AgendaScreen(
     onOpenSettings: () -> Unit,
     onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
+    quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
+    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     modifier: Modifier = Modifier,
     viewModel: AgendaViewModel = hiltViewModel(),
 ) {
@@ -120,6 +123,7 @@ fun AgendaScreen(
             CalendarDrawer(
                 currentView = selectedView,
                 currentDate = anchor,
+                viewOrder = drawerViewOrder,
                 onSelectView = { view ->
                     onSelectView(view)
                     scope.launch { drawerState.close() }
@@ -140,7 +144,7 @@ fun AgendaScreen(
             topBar = {
                 AgendaTopBar(
                     selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next()) },
+                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     scrollBehavior = scrollBehavior,

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

@@ -59,6 +59,7 @@ fun CalendarDrawer(
     onSelectView: (CalendarView) -> Unit,
     onJumpToDate: (LocalDate) -> Unit,
     onSettings: () -> Unit,
+    viewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
 ) {
     var showDatePicker by remember { mutableStateOf(false) }
 
@@ -73,10 +74,10 @@ fun CalendarDrawer(
             DrawerHeader()
 
             DrawerSectionHeader(stringResource(R.string.view_section))
-            IMPLEMENTED_VIEWS.forEachIndexed { index, view ->
+            viewOrder.forEachIndexed { index, view ->
                 GroupedRow(
                     title = stringResource(view.labelRes),
-                    position = positionOf(index, IMPLEMENTED_VIEWS.size),
+                    position = positionOf(index, viewOrder.size),
                     selected = view == currentView,
                     minHeight = 56.dp,
                     leading = { Icon(view.icon, contentDescription = null) },

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

@@ -45,11 +45,39 @@ val IMPLEMENTED_VIEWS: List<CalendarView> =
 
 /** Next view in [available], wrapping around. Falls back to Month if absent. */
 fun CalendarView.next(available: List<CalendarView> = IMPLEMENTED_VIEWS): CalendarView {
+    if (available.isEmpty()) return this
     val i = available.indexOf(this)
-    if (i < 0) return available.firstOrNull() ?: CalendarView.Month
+    if (i < 0) return available.first()
     return available[(i + 1) % available.size]
 }
 
+/**
+ * The user's customisation of the top-bar quick-switch button (#24): which views
+ * it cycles through ([enabled]) and in what [order]. [order] always lists every
+ * implemented view — the settings screen reorders the whole set — while [cycle]
+ * is the subset the pill actually steps through, in [order]. The navigation
+ * drawer keeps its own separate order and always lists every view, so a view
+ * disabled here stays reachable there.
+ */
+data class QuickSwitchConfig(
+    val order: List<CalendarView>,
+    val enabled: Set<CalendarView>,
+) {
+    /** Views the pill steps through, in [order]. */
+    val cycle: List<CalendarView> get() = order.filter { it in enabled }
+
+    companion object {
+        /** All views, in default order, all enabled. */
+        val Default = QuickSwitchConfig(IMPLEMENTED_VIEWS, IMPLEMENTED_VIEWS.toSet())
+
+        /**
+         * Fewest views that keep the switch meaningful — a "switch" needs at
+         * least two targets, so the settings screen blocks disabling below this.
+         */
+        const val MIN_ENABLED = 2
+    }
+}
+
 /**
  * The top-level view back stack (bottom → top): the [default] home view always
  * sits at the bottom. Pressing back pops one level until only the home view

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

@@ -0,0 +1,103 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.foundation.gestures.detectDragGestures
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.layout.onSizeChanged
+import androidx.compose.ui.zIndex
+
+/**
+ * A vertical list whose rows can be dragged into a new order by their handle.
+ *
+ * Built for the short, fixed grouped-card lists in Settings (#24) — no external
+ * dependency and no [androidx.compose.foundation.lazy.LazyColumn] (the settings
+ * screens are a single [androidx.compose.foundation.verticalScroll] column, which
+ * can't nest a scrolling list). [rowContent] receives the [Position] for the
+ * row's current place in the order (so it can reuse [GroupedRow]'s card shaping)
+ * and a `dragHandle` [Modifier] to attach to whatever element should start a
+ * drag. While a row is held it floats above the others, which reflow live; the
+ * final order is committed once via [onReorder] on release, so the persistence
+ * layer sees one write per gesture, not one per crossed row.
+ *
+ * Reordering is measurement-driven: each row reports its own height, so rows of
+ * unequal height still swap at the right point.
+ */
+@Composable
+fun <T> ReorderableColumn(
+    items: List<T>,
+    keyOf: (T) -> Any,
+    onReorder: (List<T>) -> Unit,
+    modifier: Modifier = Modifier,
+    rowContent: @Composable (item: T, position: Position, dragHandle: Modifier, isDragging: Boolean) -> Unit,
+) {
+    // Local working copy so rows reflow instantly during a drag; re-seeded when
+    // the incoming list changes (including the echo of our own committed order).
+    var order by remember(items) { mutableStateOf(items) }
+    var draggedKey by remember { mutableStateOf<Any?>(null) }
+    // Translation of the held row from its settled slot; a swap folds one slot
+    // height back into this so the row stays under the finger across the swap.
+    var dragOffsetY by remember { mutableStateOf(0f) }
+    val heights = remember { mutableStateMapOf<Any, Int>() }
+
+    Column(modifier) {
+        order.forEachIndexed { index, item ->
+            val key = keyOf(item)
+            val isDragging = key == draggedKey
+            val dragHandle = Modifier.pointerInput(key) {
+                detectDragGestures(
+                    onDragStart = {
+                        draggedKey = key
+                        dragOffsetY = 0f
+                    },
+                    onDragEnd = {
+                        draggedKey = null
+                        dragOffsetY = 0f
+                        onReorder(order)
+                    },
+                    onDragCancel = {
+                        draggedKey = null
+                        dragOffsetY = 0f
+                    },
+                    onDrag = { change, dragAmount ->
+                        change.consume()
+                        dragOffsetY += dragAmount.y
+                        val cur = order.indexOfFirst { keyOf(it) == key }
+                        if (cur < 0) return@detectDragGestures
+                        // Swap once the row has travelled past half of the
+                        // neighbour it's heading toward, in the drag direction.
+                        if (dragAmount.y > 0 && cur < order.lastIndex) {
+                            val nextHeight = heights[keyOf(order[cur + 1])] ?: 0
+                            if (nextHeight > 0 && dragOffsetY > nextHeight / 2f) {
+                                order = order.toMutableList().apply { add(cur + 1, removeAt(cur)) }
+                                dragOffsetY -= nextHeight
+                            }
+                        } else if (dragAmount.y < 0 && cur > 0) {
+                            val prevHeight = heights[keyOf(order[cur - 1])] ?: 0
+                            if (prevHeight > 0 && dragOffsetY < -prevHeight / 2f) {
+                                order = order.toMutableList().apply { add(cur - 1, removeAt(cur)) }
+                                dragOffsetY += prevHeight
+                            }
+                        }
+                    },
+                )
+            }
+            Box(
+                Modifier
+                    .onSizeChanged { heights[key] = it.height }
+                    .zIndex(if (isDragging) 1f else 0f)
+                    .graphicsLayer { translationY = if (isDragging) dragOffsetY else 0f },
+            ) {
+                rowContent(item, positionOf(index, order.size), dragHandle, isDragging)
+            }
+        }
+    }
+}

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

@@ -72,6 +72,7 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
 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.NowLine
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
 import de.jeanlucmakiola.calendula.ui.common.calendarSlideTransition
@@ -116,6 +117,8 @@ fun DayScreen(
     onOpenSettings: () -> Unit,
     onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
+    quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
+    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     modifier: Modifier = Modifier,
     initialDateIso: String? = null,
     viewModel: DayViewModel = hiltViewModel(),
@@ -175,6 +178,7 @@ fun DayScreen(
             CalendarDrawer(
                 currentView = selectedView,
                 currentDate = date,
+                viewOrder = drawerViewOrder,
                 onSelectView = { view ->
                     onSelectView(view)
                     scope.launch { drawerState.close() }
@@ -196,7 +200,7 @@ fun DayScreen(
                 DayTopBar(
                     date = date,
                     selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next()) },
+                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     scrollBehavior = scrollBehavior,

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

@@ -68,6 +68,7 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
 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.rememberCurrentMinute
@@ -98,6 +99,8 @@ fun MonthScreen(
     onOpenSettings: () -> Unit,
     onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
+    quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
+    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     modifier: Modifier = Modifier,
     viewModel: MonthViewModel = hiltViewModel(),
 ) {
@@ -157,6 +160,7 @@ fun MonthScreen(
             CalendarDrawer(
                 currentView = selectedView,
                 currentDate = LocalDate(month.year, month.month, 1),
+                viewOrder = drawerViewOrder,
                 onSelectView = { view ->
                     onSelectView(view)
                     scope.launch { drawerState.close() }
@@ -178,7 +182,7 @@ fun MonthScreen(
                 MonthTopBar(
                     month = month,
                     selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next()) },
+                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     scrollBehavior = scrollBehavior,

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

@@ -41,6 +41,8 @@ import androidx.compose.material.icons.filled.BugReport
 import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material.icons.filled.Dashboard
 import androidx.compose.material.icons.filled.Check
+import androidx.compose.material.icons.filled.DragHandle
+import androidx.compose.material.icons.filled.SwapVert
 import androidx.compose.material.icons.filled.ExpandLess
 import androidx.compose.material.icons.filled.ExpandMore
 import androidx.compose.material.icons.filled.Favorite
@@ -99,9 +101,13 @@ import de.jeanlucmakiola.calendula.ui.common.calendarCollapseExit
 import de.jeanlucmakiola.calendula.ui.common.calendarExpandEnter
 import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
+import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.CollapsingScaffold
 import de.jeanlucmakiola.calendula.ui.common.GroupedRow
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
+import de.jeanlucmakiola.calendula.ui.common.ReorderableColumn
+import de.jeanlucmakiola.calendula.ui.common.icon
 import de.jeanlucmakiola.calendula.ui.common.labelRes
 import de.jeanlucmakiola.calendula.ui.common.CalendarColorChip
 import de.jeanlucmakiola.calendula.ui.common.OptionPicker
@@ -121,7 +127,7 @@ import java.time.format.TextStyle as JavaTextStyle
 import java.util.Calendar
 
 /** The settings sub-screens reached from the hub's category rows. */
-private enum class SettingsSection { Appearance, EventForm, Notifications }
+private enum class SettingsSection { Appearance, Views, EventForm, Notifications }
 
 /**
  * Token-based accent for a leading icon chip (container / on-container pair).
@@ -166,6 +172,13 @@ fun SettingsScreen(
         ) {
             AppearanceScreen(state = state, viewModel = viewModel, onBack = { section = null })
         }
+        AnimatedVisibility(
+            visible = section == SettingsSection.Views,
+            enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
+            exit = slideOutHorizontally(slideSpec) { it } + fadeOut(),
+        ) {
+            ViewsScreen(state = state, viewModel = viewModel, onBack = { section = null })
+        }
         AnimatedVisibility(
             visible = section == SettingsSection.EventForm,
             enter = slideInHorizontally(slideSpec) { it } + fadeIn(),
@@ -204,6 +217,13 @@ private fun SettingsHub(
             leading = { CategoryIcon(Icons.Default.Palette, ChipAccent.Neutral) },
             onClick = { onOpenSection(SettingsSection.Appearance) },
         )
+        GroupedRow(
+            title = stringResource(R.string.settings_section_views),
+            summary = stringResource(R.string.settings_views_subtitle),
+            position = Position.Middle,
+            leading = { CategoryIcon(Icons.Default.SwapVert, ChipAccent.Neutral) },
+            onClick = { onOpenSection(SettingsSection.Views) },
+        )
         GroupedRow(
             title = stringResource(R.string.settings_section_event_form),
             summary = stringResource(R.string.settings_event_form_subtitle),
@@ -664,6 +684,129 @@ private fun AppearanceScreen(
     }
 }
 
+/**
+ * Views (#24): reorder the top-bar quick-switch cycle and choose which views it
+ * steps through, plus reorder the navigation-drawer list. Two independent lists —
+ * a view disabled in the quick-switch cycle is still reachable from the drawer,
+ * which always lists every view. The switch needs at least two targets, so the
+ * last [QuickSwitchConfig.MIN_ENABLED] enabled views can't be turned off.
+ */
+@Composable
+private fun ViewsScreen(
+    state: SettingsUiState,
+    viewModel: SettingsViewModel,
+    onBack: () -> Unit,
+) {
+    CollapsingScaffold(
+        title = stringResource(R.string.settings_section_views),
+        onBack = onBack,
+    ) {
+        val config = state.quickSwitchConfig
+
+        SectionHeader(stringResource(R.string.settings_quick_switch_header))
+        SettingsHint(stringResource(R.string.settings_quick_switch_hint))
+        Spacer(Modifier.height(8.dp))
+        // Turning a view off is blocked once only the minimum remain enabled.
+        val canDisable = config.enabled.size > QuickSwitchConfig.MIN_ENABLED
+        ReorderableColumn(
+            items = config.order,
+            keyOf = { it },
+            onReorder = { viewModel.setQuickSwitchConfig(config.copy(order = it)) },
+        ) { view, position, dragHandle, isDragging ->
+            val checked = view in config.enabled
+            ViewRow(
+                view = view,
+                position = position,
+                isDragging = isDragging,
+                dragHandle = dragHandle,
+                dimmed = !checked,
+                trailing = {
+                    Switch(
+                        checked = checked,
+                        // Keep the last two on: with fewer, the pill can't switch.
+                        enabled = !checked || canDisable,
+                        onCheckedChange = { on ->
+                            val enabled = if (on) config.enabled + view else config.enabled - view
+                            viewModel.setQuickSwitchConfig(config.copy(enabled = enabled))
+                        },
+                    )
+                },
+            )
+        }
+
+        Spacer(Modifier.height(24.dp))
+        SectionHeader(stringResource(R.string.settings_drawer_order_header))
+        SettingsHint(stringResource(R.string.settings_drawer_order_hint))
+        Spacer(Modifier.height(8.dp))
+        ReorderableColumn(
+            items = state.drawerViewOrder,
+            keyOf = { it },
+            onReorder = { viewModel.setDrawerViewOrder(it) },
+        ) { view, position, dragHandle, isDragging ->
+            ViewRow(
+                view = view,
+                position = position,
+                isDragging = isDragging,
+                dragHandle = dragHandle,
+            )
+        }
+    }
+}
+
+/** One reorderable view row: the view's icon and name, an optional [trailing]
+ *  control, and a drag handle carrying the [dragHandle] gesture modifier. */
+@Composable
+private fun ViewRow(
+    view: CalendarView,
+    position: Position,
+    isDragging: Boolean,
+    dragHandle: Modifier,
+    dimmed: Boolean = false,
+    trailing: @Composable (() -> Unit)? = null,
+) {
+    GroupedRow(
+        title = stringResource(view.labelRes),
+        position = position,
+        dimmed = dimmed,
+        minHeight = 64.dp,
+        container = if (isDragging) MaterialTheme.colorScheme.secondaryContainer else null,
+        leading = {
+            Icon(
+                imageVector = view.icon,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+        },
+        trailing = {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                trailing?.invoke()
+                if (trailing != null) Spacer(Modifier.width(8.dp))
+                Box(
+                    modifier = dragHandle.size(48.dp),
+                    contentAlignment = Alignment.Center,
+                ) {
+                    Icon(
+                        imageVector = Icons.Default.DragHandle,
+                        contentDescription = stringResource(R.string.reorder_drag_handle),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+        },
+    )
+}
+
+/** Muted supporting text under a [SectionHeader], matching the form-fields hint. */
+@Composable
+private fun SettingsHint(text: String) {
+    Text(
+        text = text,
+        style = MaterialTheme.typography.bodyMedium,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(horizontal = 16.dp, vertical = 4.dp),
+    )
+}
+
 @Composable
 private fun EventFormScreen(
     state: SettingsUiState,

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

@@ -9,6 +9,8 @@ import de.jeanlucmakiola.calendula.domain.CalendarSource
 import de.jeanlucmakiola.calendula.domain.EventFormField
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 
 /**
  * Settings screen state (M4). Persisted preferences are instant to read, so
@@ -37,6 +39,10 @@ data class SettingsUiState(
     val agendaShowRangeBar: Boolean = true,
     /** The calendar view the app opens on, and the home of the view back stack (M1). */
     val defaultView: CalendarView = CalendarView.Week,
+    /** Which views the top-bar quick-switch button cycles through, and their order (#24). */
+    val quickSwitchConfig: QuickSwitchConfig = QuickSwitchConfig.Default,
+    /** Order of the views in the navigation drawer (#24); every view is always listed. */
+    val drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     /** Optional event-form fields shown by default (rest behind "more fields"). */
     val defaultFormFields: Set<EventFormField> = SettingsPrefs.DEFAULT_FORM_FIELDS,
     /** Whether the new-event form auto-focuses the title and shows the keyboard (#10). */

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

@@ -21,6 +21,7 @@ import de.jeanlucmakiola.calendula.domain.EventFormField
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
 import de.jeanlucmakiola.calendula.ui.agenda.storageValue
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_PAST_DISPLAY_KEY
 import de.jeanlucmakiola.calendula.widget.agenda.AGENDA_RANGE_KEY
 import de.jeanlucmakiola.calendula.widget.agenda.AgendaWidget
@@ -103,8 +104,14 @@ class SettingsViewModel @Inject constructor(
                 prefs.autofocusEventTitle,
                 prefs.pastEventDisplay,
                 prefs.dimCompletedEvents,
-                ::MiscSettings,
+                // View customisation (#24) folded into one flow so it fits this
-            ),
+                // group — the outer combine is already at its five-arg limit.
+                combine(prefs.quickSwitchConfig, prefs.drawerViewOrder) { quickSwitch, drawer ->
+                    ViewCustomization(quickSwitch, drawer)
+                },
+            ) { showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization ->
+                MiscSettings(showRangeBar, autofocus, pastEvents, dimCompleted, viewCustomization)
+            },
         ) { base, defaults, overrides, views, misc ->
             base.copy(
                 defaultView = views.defaultView,
@@ -116,6 +123,8 @@ class SettingsViewModel @Inject constructor(
                 autofocusEventTitle = misc.autofocusEventTitle,
                 pastEventDisplay = misc.pastEventDisplay,
                 dimCompletedEvents = misc.dimCompletedEvents,
+                quickSwitchConfig = misc.viewCustomization.quickSwitch,
+                drawerViewOrder = misc.viewCustomization.drawerOrder,
                 allowColorOnUnsupportedCalendars = defaults.allowColor,
                 defaultReminderMinutes = defaults.defaultReminder,
                 defaultAllDayReminderMinutes = defaults.allDayReminder,
@@ -164,6 +173,12 @@ class SettingsViewModel @Inject constructor(
         val autofocusEventTitle: Boolean,
         val pastEventDisplay: PastEventDisplay,
         val dimCompletedEvents: Boolean,
+        val viewCustomization: ViewCustomization,
+    )
+
+    private data class ViewCustomization(
+        val quickSwitch: QuickSwitchConfig,
+        val drawerOrder: List<CalendarView>,
     )
 
     fun setThemeMode(mode: ThemeMode) {
@@ -247,6 +262,14 @@ class SettingsViewModel @Inject constructor(
         viewModelScope.launch { prefs.setFormFieldDefault(field, enabled) }
     }
 
+    fun setQuickSwitchConfig(config: QuickSwitchConfig) {
+        viewModelScope.launch { prefs.setQuickSwitchConfig(config) }
+    }
+
+    fun setDrawerViewOrder(order: List<CalendarView>) {
+        viewModelScope.launch { prefs.setDrawerViewOrder(order) }
+    }
+
     fun setRemindersEnabled(enabled: Boolean) {
         viewModelScope.launch { prefs.setRemindersEnabled(enabled) }
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/week/WeekScreen.kt

@@ -81,6 +81,7 @@ import de.jeanlucmakiola.calendula.ui.common.CalendarDrawer
 import de.jeanlucmakiola.calendula.ui.common.CalendarFabColumn
 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.NowLine
@@ -131,6 +132,8 @@ fun WeekScreen(
     onOpenSettings: () -> Unit,
     onOpenSearch: () -> Unit,
     onCreateEvent: (LocalDate, Int?) -> Unit,
+    quickSwitchViews: List<CalendarView> = IMPLEMENTED_VIEWS,
+    drawerViewOrder: List<CalendarView> = IMPLEMENTED_VIEWS,
     modifier: Modifier = Modifier,
     viewModel: WeekViewModel = hiltViewModel(),
 ) {
@@ -195,6 +198,7 @@ fun WeekScreen(
             CalendarDrawer(
                 currentView = selectedView,
                 currentDate = weekStart,
+                viewOrder = drawerViewOrder,
                 onSelectView = { view ->
                     onSelectView(view)
                     scope.launch { drawerState.close() }
@@ -216,7 +220,7 @@ fun WeekScreen(
                 WeekTopBar(
                     weekStart = weekStart,
                     selectedView = selectedView,
-                    onCycleView = { onSelectView(selectedView.next()) },
+                    onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     scrollBehavior = scrollBehavior,

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

@@ -308,6 +308,12 @@
         <item quantity="one">%d day</item>
         <item quantity="other">%d days</item>
     </plurals>
+    <string name="settings_section_views">Views</string>
+    <string name="settings_quick_switch_header">Quick-switch button</string>
+    <string name="settings_quick_switch_hint">Choose which views the top-right button cycles through, and drag to reorder them. Turned-off views stay reachable from the navigation menu.</string>
+    <string name="settings_drawer_order_header">Navigation menu</string>
+    <string name="settings_drawer_order_hint">Drag to reorder the views listed in the navigation menu.</string>
+    <string name="reorder_drag_handle">Drag to reorder</string>
     <string name="settings_section_event_form">New event form</string>
     <string name="settings_form_fields_hint">Fields shown by default — everything else sits behind \"More fields\"</string>
     <string name="settings_autofocus_title">Focus title on new event</string>
@@ -343,6 +349,7 @@
     <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_views_subtitle">Quick-switch button and menu order</string>
     <string name="settings_event_form_subtitle">Default fields for new events</string>
     <string name="settings_notifications_subtitle">Event reminders</string>
     <string name="settings_section_about">About</string>

app/src/test/java/de/jeanlucmakiola/calendula/data/prefs/SettingsPrefsTest.kt

@@ -6,6 +6,9 @@ import androidx.datastore.preferences.core.Preferences
 import com.google.common.truth.Truth.assertThat
 import de.jeanlucmakiola.calendula.domain.EventFormField
 import de.jeanlucmakiola.calendula.ui.agenda.AgendaRange
+import de.jeanlucmakiola.calendula.ui.common.CalendarView
+import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
+import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.runTest
 import kotlinx.datetime.DayOfWeek
@@ -149,6 +152,78 @@ class SettingsPrefsTest {
         assertThat(prefs.defaultFormFields.first()).isEmpty()
     }
 
+    @Test
+    fun `quick-switch defaults to every view enabled in default order`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        val config = prefs.quickSwitchConfig.first()
+        assertThat(config.order).containsExactlyElementsIn(IMPLEMENTED_VIEWS).inOrder()
+        assertThat(config.enabled).containsExactlyElementsIn(IMPLEMENTED_VIEWS)
+        assertThat(config.cycle).containsExactlyElementsIn(IMPLEMENTED_VIEWS).inOrder()
+    }
+
+    @Test
+    fun `quick-switch config round-trips order and disabled views`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        val config = QuickSwitchConfig(
+            order = listOf(CalendarView.Agenda, CalendarView.Month, CalendarView.Week, CalendarView.Day),
+            enabled = setOf(CalendarView.Agenda, CalendarView.Month),
+        )
+        prefs.setQuickSwitchConfig(config)
+        val loaded = prefs.quickSwitchConfig.first()
+        assertThat(loaded.order).containsExactly(
+            CalendarView.Agenda, CalendarView.Month, CalendarView.Week, CalendarView.Day,
+        ).inOrder()
+        assertThat(loaded.enabled).containsExactly(CalendarView.Agenda, CalendarView.Month)
+        assertThat(loaded.cycle).containsExactly(CalendarView.Agenda, CalendarView.Month).inOrder()
+    }
+
+    @Test
+    fun `quick-switch parse appends missing views enabled and drops unknowns`(@TempDir tempDir: Path) = runTest {
+        val store = newDataStore(tempDir)
+        val prefs = SettingsPrefs(store)
+        // Only Day (disabled) and Week stored, plus a bogus name; Month & Agenda absent.
+        store.updateData { p ->
+            val m = p.toMutablePreferences()
+            m[SettingsPrefs.QUICK_SWITCH_VIEWS_KEY] = "!Day,Week,Hologram"
+            m
+        }
+        val config = prefs.quickSwitchConfig.first()
+        // Stored order first (Day, Week), then the omitted views in default order.
+        assertThat(config.order).containsExactly(
+            CalendarView.Day, CalendarView.Week, CalendarView.Month, CalendarView.Agenda,
+        ).inOrder()
+        // Day was explicitly disabled; the appended Month & Agenda default enabled.
+        assertThat(config.enabled).containsExactly(
+            CalendarView.Week, CalendarView.Month, CalendarView.Agenda,
+        )
+    }
+
+    @Test
+    fun `drawer order defaults to the implemented order and round-trips`(@TempDir tempDir: Path) = runTest {
+        val prefs = SettingsPrefs(newDataStore(tempDir))
+        assertThat(prefs.drawerViewOrder.first()).containsExactlyElementsIn(IMPLEMENTED_VIEWS).inOrder()
+        prefs.setDrawerViewOrder(
+            listOf(CalendarView.Agenda, CalendarView.Day, CalendarView.Week, CalendarView.Month),
+        )
+        assertThat(prefs.drawerViewOrder.first()).containsExactly(
+            CalendarView.Agenda, CalendarView.Day, CalendarView.Week, CalendarView.Month,
+        ).inOrder()
+    }
+
+    @Test
+    fun `drawer order parse appends missing views and drops unknowns`(@TempDir tempDir: Path) = runTest {
+        val store = newDataStore(tempDir)
+        val prefs = SettingsPrefs(store)
+        store.updateData { p ->
+            val m = p.toMutablePreferences()
+            m[SettingsPrefs.DRAWER_VIEW_ORDER_KEY] = "Agenda,Nope,Week"
+            m
+        }
+        assertThat(prefs.drawerViewOrder.first()).containsExactly(
+            CalendarView.Agenda, CalendarView.Week, CalendarView.Month, CalendarView.Day,
+        ).inOrder()
+    }
+
     @Test
     fun `unknown stored form-field names are dropped`(@TempDir tempDir: Path) = runTest {
         val store = newDataStore(tempDir)

app/src/test/java/de/jeanlucmakiola/calendula/ui/common/ViewBackStackTest.kt

@@ -91,4 +91,33 @@ class ViewBackStackTest {
         assertThat(viewBaseStack(CalendarView.Agenda, CalendarView.Agenda))
             .containsExactly(CalendarView.Agenda)
     }
+
+    @Test
+    fun `next cycles through the configured views in order, wrapping around`() {
+        val cycle = listOf(CalendarView.Month, CalendarView.Agenda)
+        assertThat(CalendarView.Month.next(cycle)).isEqualTo(CalendarView.Agenda)
+        // Wraps back to the first from the last.
+        assertThat(CalendarView.Agenda.next(cycle)).isEqualTo(CalendarView.Month)
+    }
+
+    @Test
+    fun `next from a view outside the cycle lands on the first enabled view`() {
+        // Day was disabled in the quick-switch cycle but is still the current view.
+        val cycle = listOf(CalendarView.Week, CalendarView.Month)
+        assertThat(CalendarView.Day.next(cycle)).isEqualTo(CalendarView.Week)
+    }
+
+    @Test
+    fun `next on an empty cycle stays put`() {
+        assertThat(CalendarView.Week.next(emptyList())).isEqualTo(CalendarView.Week)
+    }
+
+    @Test
+    fun `quick-switch cycle keeps enabled views in their configured order`() {
+        val config = QuickSwitchConfig(
+            order = listOf(CalendarView.Agenda, CalendarView.Day, CalendarView.Month, CalendarView.Week),
+            enabled = setOf(CalendarView.Agenda, CalendarView.Month),
+        )
+        assertThat(config.cycle).containsExactly(CalendarView.Agenda, CalendarView.Month).inOrder()
+    }
 }