Hide the quick-switch button below two views (#150) (#221)

Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/221

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

@@ -135,6 +135,7 @@ fun AgendaScreen(
                 AgendaTopBar(
                     selectedView = selectedView,
                     onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
+                    quickSwitchViews = quickSwitchViews,
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     showTodayButton = todayInToolbar,
@@ -409,6 +410,7 @@ private fun AgendaEmpty(modifier: Modifier = Modifier) {
 private fun AgendaTopBar(
     selectedView: CalendarView,
     onCycleView: () -> Unit,
+    quickSwitchViews: List<CalendarView>,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
     showTodayButton: Boolean,
@@ -440,6 +442,7 @@ private fun AgendaTopBar(
             }
             ViewSwitcherPill(
                 current = selectedView,
+                cycle = quickSwitchViews,
                 onCycle = onCycleView,
                 modifier = Modifier.padding(end = 8.dp),
             )

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

@@ -57,7 +57,8 @@ fun CalendarView.next(available: List<CalendarView> = IMPLEMENTED_VIEWS): Calend
  * 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.
+ * disabled here stays reachable there — including when [cycle] is emptied and
+ * the pill disappears altogether.
  */
 data class QuickSwitchConfig(
     val order: List<CalendarView>,
@@ -67,14 +68,15 @@ data class QuickSwitchConfig(
     val cycle: List<CalendarView> get() = order.filter { it in enabled }
 
     companion object {
+        /**
+         * Fewest views that keep the switch meaningful. A single target is not a
+         * switch, so below this the pill is hidden rather than special-cased (#150);
+         * the drawer still reaches every view.
+         */
+        const val MIN_CYCLE = 2
+
         /** 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
     }
 }
 

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

@@ -10,13 +10,19 @@ import androidx.compose.ui.res.stringResource
 /**
  * Top-bar pill that shows the current view and cycles to the next one on tap
  * (spec M1: Month → Week → Day → Month, restricted to [IMPLEMENTED_VIEWS]).
+ *
+ * Renders nothing when [cycle] holds fewer than [QuickSwitchConfig.MIN_CYCLE]
+ * views (#150), so it drops straight into an app bar's `actions` slot without a
+ * wrapping condition — the same way [TodayAction] handles being turned off.
  */
 @Composable
 fun ViewSwitcherPill(
     current: CalendarView,
+    cycle: List<CalendarView>,
     onCycle: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
+    if (cycle.size < QuickSwitchConfig.MIN_CYCLE) return
     FilledTonalButton(
         onClick = onCycle,
         shape = MaterialTheme.shapes.large,

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

@@ -243,6 +243,7 @@ fun DayScreen(
                     currentYear = currentYear,
                     selectedView = selectedView,
                     onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
+                    quickSwitchViews = quickSwitchViews,
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     onJumpToDate = jumpToDate,
@@ -411,6 +412,7 @@ private fun DayTopBar(
     currentYear: Int,
     selectedView: CalendarView,
     onCycleView: () -> Unit,
+    quickSwitchViews: List<CalendarView>,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
     onJumpToDate: (LocalDate) -> Unit,
@@ -445,6 +447,7 @@ private fun DayTopBar(
             }
             ViewSwitcherPill(
                 current = selectedView,
+                cycle = quickSwitchViews,
                 onCycle = onCycleView,
                 modifier = Modifier.padding(end = 8.dp),
             )

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

@@ -387,6 +387,7 @@ fun MonthScreen(
                     titleDate = LocalDate(titleMonth.year, titleMonth.month, 1),
                     selectedView = selectedView,
                     onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
+                    quickSwitchViews = quickSwitchViews,
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     onJumpToDate = jumpToDate,
@@ -651,6 +652,7 @@ private fun MonthTopBar(
     titleDate: LocalDate,
     selectedView: CalendarView,
     onCycleView: () -> Unit,
+    quickSwitchViews: List<CalendarView>,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
     onJumpToDate: (LocalDate) -> Unit,
@@ -684,6 +686,7 @@ private fun MonthTopBar(
             }
             ViewSwitcherPill(
                 current = selectedView,
+                cycle = quickSwitchViews,
                 onCycle = onCycleView,
                 modifier = Modifier.padding(end = 8.dp),
             )

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

@@ -591,15 +591,15 @@ class SettingsViewModel @Inject constructor(
 
     /**
      * Enable or disable [view] in the quick-switch cycle, via an atomic
-     * read-modify-write so a concurrent reorder can't clobber it. The
+     * read-modify-write so a concurrent reorder can't clobber it. Any number of
-     * MIN_ENABLED floor is re-checked inside the transform, because the screen's
+     * views may be turned off; below two the pill hides itself (#150).
-     * own guard reads an async-echoed snapshot.
      */
     fun setQuickSwitchViewEnabled(view: CalendarView, enabled: Boolean) {
         viewModelScope.launch {
             prefs.updateQuickSwitch { config ->
-                val next = if (enabled) config.enabled + view else config.enabled - view
+                config.copy(
-                if (next.size < QuickSwitchConfig.MIN_ENABLED) config else config.copy(enabled = next)
+                    enabled = if (enabled) config.enabled + view else config.enabled - view,
+                )
             }
         }
     }

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

@@ -32,7 +32,6 @@ import de.jeanlucmakiola.calendula.ui.common.AgendaRangePicker
 import de.jeanlucmakiola.calendula.ui.common.CalendarView
 import de.jeanlucmakiola.calendula.ui.common.IMPLEMENTED_VIEWS
 import de.jeanlucmakiola.calendula.ui.common.PickerDescription
-import de.jeanlucmakiola.calendula.ui.common.QuickSwitchConfig
 import de.jeanlucmakiola.calendula.ui.common.TimelineScale
 import de.jeanlucmakiola.calendula.ui.common.agendaRangeLabel
 import de.jeanlucmakiola.calendula.ui.common.descriptionRes
@@ -55,8 +54,8 @@ import java.time.format.TextStyle as JavaTextStyle
  * it belongs to, plus the two cross-view ordering lists (#24, #69).
  *
  * The quick-switch cycle and the drawer list are independent orders — a view
- * off in the cycle is still reachable from the drawer. The cycle needs at least
+ * off in the cycle is still reachable from the drawer, including when the cycle
- * [QuickSwitchConfig.MIN_ENABLED] targets.
+ * is emptied and the pill disappears (#150).
  */
 @Composable
 internal fun ViewsScreen(
@@ -221,8 +220,6 @@ internal fun ViewsScreen(
         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 },
@@ -238,8 +235,6 @@ internal fun ViewsScreen(
                 trailing = {
                     Switch(
                         checked = checked,
-                        // Keep the last two on: with fewer, the pill can't switch.
-                        enabled = !checked || canDisable,
                         onCheckedChange = { on -> viewModel.setQuickSwitchViewEnabled(view, on) },
                     )
                 },

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

@@ -266,6 +266,7 @@ fun WeekScreen(
                     currentYear = currentYear,
                     selectedView = selectedView,
                     onCycleView = { onSelectView(selectedView.next(quickSwitchViews)) },
+                    quickSwitchViews = quickSwitchViews,
                     onOpenDrawer = { scope.launch { drawerState.open() } },
                     onOpenSearch = onOpenSearch,
                     onJumpToDate = jumpToDate,
@@ -446,6 +447,7 @@ private fun WeekTopBar(
     currentYear: Int,
     selectedView: CalendarView,
     onCycleView: () -> Unit,
+    quickSwitchViews: List<CalendarView>,
     onOpenDrawer: () -> Unit,
     onOpenSearch: () -> Unit,
     onJumpToDate: (LocalDate) -> Unit,
@@ -480,6 +482,7 @@ private fun WeekTopBar(
             }
             ViewSwitcherPill(
                 current = selectedView,
+                cycle = quickSwitchViews,
                 onCycle = onCycleView,
                 modifier = Modifier.padding(end = 8.dp),
             )

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

@@ -496,7 +496,7 @@
     <string name="month_split_expand">Show the whole month</string>
     <string name="month_split_collapse">Show the day\'s events</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_quick_switch_hint">Choose which views the top-right button cycles through, and drag to reorder them. With fewer than two views turned on the button is hidden. 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>

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

@@ -120,4 +120,30 @@ class ViewBackStackTest {
         )
         assertThat(config.cycle).containsExactly(CalendarView.Agenda, CalendarView.Month).inOrder()
     }
+
+    @Test
+    fun `a cycle can be emptied down to no views at all`() {
+        // #150: the settings screen no longer holds a floor, so every view may go.
+        val config = QuickSwitchConfig(order = IMPLEMENTED_VIEWS, enabled = emptySet())
+        assertThat(config.cycle).isEmpty()
+        assertThat(config.cycle.size).isLessThan(QuickSwitchConfig.MIN_CYCLE)
+    }
+
+    @Test
+    fun `one enabled view is below the cycle minimum, so the pill hides`() {
+        // A single target is not a switch — it hides rather than becoming a
+        // jump-to-one-view button, which would be dead once you were there.
+        val config = QuickSwitchConfig(order = IMPLEMENTED_VIEWS, enabled = setOf(CalendarView.Day))
+        assertThat(config.cycle).containsExactly(CalendarView.Day)
+        assertThat(config.cycle.size).isLessThan(QuickSwitchConfig.MIN_CYCLE)
+    }
+
+    @Test
+    fun `two enabled views are enough to show the pill`() {
+        val config = QuickSwitchConfig(
+            order = IMPLEMENTED_VIEWS,
+            enabled = setOf(CalendarView.Day, CalendarView.Month),
+        )
+        assertThat(config.cycle.size).isAtLeast(QuickSwitchConfig.MIN_CYCLE)
+    }
 }