fix(todo): the Plan's button before search, and its sheet without the navigation bar

Today's and Upcoming's Plan button stood between search and Display; it
stands before the three every tab has now (TabScreen's `leadingActions`).
On a phone, where the Plan opens over the hours' foot, its icon is
Lucide's panel-bottom-open (panel-bottom-close while open); beside the
hours on wider windows it keeps the panel at the right.

While a phone's Plan is open, the navigation bar steps aside, as it does
while tasks are being chosen: it floated over the Plan's tasks, and the
Plan can't be a modal sheet, its rows being dragged out onto the hours.
`NavigationBarHold`, kept by TodoShell, holds it away while anyone asks;
closing the Plan, or back, which closes it first, brings it back.

The Plan's heading put its projects and close button after a spacer of
one share and a flexible of four, leaving a fifth of the room after
them; they end at its edge now, as the rest of it.

Whats-New: The Plan's button stands before search, and while the Plan is open the navigation bar makes way for it.
Whats-New-De: Der Plan-Knopf steht vor der Suche, und solange der Plan offen ist, macht ihm die Navigationsleiste Platz.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/lib/src/tabs/navigation_bar_hold.dart

@@ -0,0 +1,47 @@
+import 'package:material_ui/material_ui.dart';
+
+/// Who holds the navigation bar away below medium windows (the developer's
+/// review, 7 Nov 2026): a phone's Plan over the hours' foot, its rows
+/// dragged onto them, so it can't be a modal sheet, yet the bar floated
+/// over its tasks. Held by anyone, the bar steps aside; released by all,
+/// it comes back. `TodoShell` keeps it, and [NavigationBarHoldScope] hands
+/// it down.
+class NavigationBarHold() extends ChangeNotifier {
+  final _holders = <Object>{};
+  bool _disposed = false;
+
+  /// Whether anyone holds the bar away.
+  bool get held => _holders.isNotEmpty;
+
+  /// [holder] holds the bar away, or no longer where [hold] is false.
+  void set(Object holder, {required bool hold}) {
+    if (_disposed) {
+      return;
+    }
+    final changed = hold ? _holders.add(holder) : _holders.remove(holder);
+    if (changed) {
+      notifyListeners();
+    }
+  }
+
+  @override
+  void dispose() {
+    _disposed = true;
+    super.dispose();
+  }
+}
+
+/// Hands [notifier] down to the tabs.
+class const NavigationBarHoldScope({
+  required final NavigationBarHold notifier,
+  required super.child,
+  super.key,
+}) extends InheritedWidget {
+  /// The hold above [context], if any; nothing rebuilds as it changes.
+  static NavigationBarHold? maybeOf(BuildContext context) =>
+      context.getInheritedWidgetOfExactType<NavigationBarHoldScope>()?.notifier;
+
+  @override
+  bool updateShouldNotify(NavigationBarHoldScope oldWidget) =>
+      notifier != oldWidget.notifier;
+}

apps/todo/halkyon_todo_flutter/lib/src/tabs/plan_host.dart

@@ -4,6 +4,7 @@ import 'package:halkyon_todo_flutter/src/app/todo_dependencies.dart';
 import 'package:halkyon_todo_flutter/src/feature/task/bloc/todo_cubit.dart';
 import 'package:halkyon_todo_flutter/src/feature/task/model/task.dart';
 import 'package:halkyon_todo_flutter/src/feature/task/model/task_views.dart';
+import 'package:halkyon_todo_flutter/src/tabs/navigation_bar_hold.dart';
 import 'package:halkyon_todo_flutter/src/tabs/pane_widths.dart';
 import 'package:halkyon_todo_flutter/src/tabs/plan_panel.dart';
 import 'package:halkyon_todo_flutter/src/tabs/side_pane.dart';
@@ -15,7 +16,8 @@ import 'package:material_ui/material_ui.dart';
 /// app bar's button shows or hides it, beside the hours from a medium width
 /// on (remembered with the person's settings, for every calendar alike),
 /// over their foot on a phone, stepping down out of the way while one of
-/// its rows is dragged onto an hour.
+/// its rows is dragged onto an hour, the navigation bar away while it is
+/// open there.
 mixin PlanHost<T extends StatefulWidget> on State<T> {
   /// The projects the Plan shows, for as long as the app runs (none: all).
   Set<String> _projects = const {};
@@ -42,11 +44,41 @@ mixin PlanHost<T extends StatefulWidget> on State<T> {
   /// Whether the phone's Plan is open, where the add button makes way.
   bool get planSheetOpen => !_wide && _sheet;
 
+  /// The navigation bar held away while the phone's Plan is open, its
+  /// rows free of it (the developer's review, 7 Nov 2026).
+  NavigationBarHold? _hold;
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    _hold = NavigationBarHoldScope.maybeOf(context);
+  }
+
+  /// The phone's Plan opened or closed, the navigation bar going or
+  /// coming with it.
+  void _setSheet(bool open) {
+    setState(() => _sheet = open);
+    _syncBar();
+  }
+
+  void _syncBar() => _hold?.set(this, hold: planSheetOpen);
+
+  @override
+  void dispose() {
+    final hold = _hold;
+    // Not while the tree is being taken down, which the bar's frame is part
+    // of: just after.
+    WidgetsBinding.instance.addPostFrameCallback(
+      (_) => hold?.set(this, hold: false),
+    );
+    super.dispose();
+  }
+
   /// The Plan shown or hidden: beside the hours, remembered with the
   /// person's settings; on a phone, its sheet.
   Future<void> _togglePlan(TodoState state) async {
     if (!_wide) {
-      setState(() => _sheet = !_sheet);
+      _setSheet(!_sheet);
       return;
     }
     final todo = PersonScope.of<TodoPerson>(context);
@@ -65,9 +97,14 @@ mixin PlanHost<T extends StatefulWidget> on State<T> {
       message: shown ? l10n.planHide : l10n.planShow,
       child: TextButton.icon(
         key: planButtonKey,
-        icon: Icon(
-          shown ? LucideIcons.panelRightClose : LucideIcons.panelRight,
-        ),
+        // Where the Plan opens: beside the hours, or over their foot on a
+        // phone (the developer's review, 7 Nov 2026).
+        icon: Icon(switch ((_wide, shown)) {
+          (true, true) => LucideIcons.panelRightClose,
+          (true, false) => LucideIcons.panelRight,
+          (false, true) => LucideIcons.panelBottomClose,
+          (false, false) => LucideIcons.panelBottomOpen,
+        }),
         label: Text(l10n.planButton(planned)),
         onPressed: () => _togglePlan(state),
       ),
@@ -91,6 +128,7 @@ mixin PlanHost<T extends StatefulWidget> on State<T> {
           WidgetsBinding.instance.addPostFrameCallback((_) {
             if (mounted) {
               setState(() {});
+              _syncBar();
             }
           });
         }
@@ -113,47 +151,56 @@ mixin PlanHost<T extends StatefulWidget> on State<T> {
         final cover = FloatingNavigationBar.coverOf(context);
         final height = constraints.maxHeight * 0.5;
         const heading = 56.0;
-        return Stack(
-          children: [
-            Positioned.fill(child: grid(_grid, _sheet ? height : 0)),
-            if (_sheet)
-              Positioned(
-                left: 0,
-                right: 0,
-                bottom: 0,
-                height: height + cover,
-                child: AnimatedSlide(
-                  duration: const Duration(milliseconds: 200),
-                  curve: Curves.easeOut,
-                  offset: Offset(
-                    0,
-                    _lowered ? (height - heading) / (height + cover) : 0,
-                  ),
-                  child: Material(
-                    key: planSheetKey,
-                    elevation: 8,
-                    color: Theme.of(context).colorScheme.surfaceContainerLow,
-                    clipBehavior: Clip.antiAlias,
-                    shape: const RoundedRectangleBorder(
-                      borderRadius: BorderRadius.vertical(
-                        top: Radius.circular(16),
-                      ),
+        // Back closes the Plan first, the navigation bar away meanwhile.
+        return PopScope(
+          canPop: !_sheet,
+          onPopInvokedWithResult: (popped, _) {
+            if (!popped && _sheet) {
+              _setSheet(false);
+            }
+          },
+          child: Stack(
+            children: [
+              Positioned.fill(child: grid(_grid, _sheet ? height : 0)),
+              if (_sheet)
+                Positioned(
+                  left: 0,
+                  right: 0,
+                  bottom: 0,
+                  height: height + cover,
+                  child: AnimatedSlide(
+                    duration: const Duration(milliseconds: 200),
+                    curve: Curves.easeOut,
+                    offset: Offset(
+                      0,
+                      _lowered ? (height - heading) / (height + cover) : 0,
                     ),
-                    child: PlanPanel(
-                      projectIds: _projects,
-                      onProjects: projects,
-                      onClose: () => setState(() => _sheet = false),
-                      onHeaderTap: () => setState(() => _lowered = false),
-                      onDragging: (dragging) {
-                        if (dragging != _lowered) {
-                          setState(() => _lowered = dragging);
-                        }
-                      },
+                    child: Material(
+                      key: planSheetKey,
+                      elevation: 8,
+                      color: Theme.of(context).colorScheme.surfaceContainerLow,
+                      clipBehavior: Clip.antiAlias,
+                      shape: const RoundedRectangleBorder(
+                        borderRadius: BorderRadius.vertical(
+                          top: Radius.circular(16),
+                        ),
+                      ),
+                      child: PlanPanel(
+                        projectIds: _projects,
+                        onProjects: projects,
+                        onClose: () => _setSheet(false),
+                        onHeaderTap: () => setState(() => _lowered = false),
+                        onDragging: (dragging) {
+                          if (dragging != _lowered) {
+                            setState(() => _lowered = dragging);
+                          }
+                        },
+                      ),
                     ),
                   ),
                 ),
-              ),
-          ],
+            ],
+          ),
         );
       },
     );

apps/todo/halkyon_todo_flutter/lib/src/tabs/plan_panel.dart

@@ -231,20 +231,24 @@ class const _PlanHeading({
                   color: theme.colorScheme.onSurfaceVariant,
                 ),
               ),
-              const Spacer(),
-              Flexible(
-                flex: 4,
-                child: TextButton.icon(
-                  key: PlanPanel.projectsKey,
-                  iconAlignment: IconAlignment.end,
-                  icon: const Icon(LucideIcons.chevronDown, size: 18),
-                  label: Text(
-                    label,
-                    maxLines: 1,
-                    overflow: TextOverflow.ellipsis,
+              // At the end, beside the close button (the developer's review,
+              // 7 Nov 2026: a spacer and a flexible of four shares left a
+              // fifth of the room after them), shortened where it is long.
+              Expanded(
+                child: Align(
+                  alignment: AlignmentDirectional.centerEnd,
+                  child: TextButton.icon(
+                    key: PlanPanel.projectsKey,
+                    iconAlignment: IconAlignment.end,
+                    icon: const Icon(LucideIcons.chevronDown, size: 18),
+                    label: Text(
+                      label,
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                    onPressed: () =>
+                        _pickProjects(context, projectIds, onProjects),
                   ),
-                  onPressed: () =>
-                      _pickProjects(context, projectIds, onProjects),
                 ),
               ),
               if (onClose case final close?)

apps/todo/halkyon_todo_flutter/lib/src/tabs/tab_screen.dart

@@ -22,9 +22,14 @@ class const TabScreen({
   /// The tab's content.
   required final Widget body,
 
-  /// The app bar's actions.
+  /// The app bar's actions, after search.
   final List<Widget> actions = const [],
 
+  /// The app bar's actions before search, the tab's own beside the ones
+  /// every tab has (Today's and Upcoming's Plan, the developer's review, 7
+  /// Nov 2026).
+  final List<Widget> leadingActions = const [],
+
   /// The screen's button, above the navigation bar.
   final Widget? floatingActionButton,
 
@@ -100,6 +105,7 @@ class const TabScreen({
               actions: choosing
                   ? const []
                   : [
+                      ...leadingActions,
                       if (search) const SearchButton(),
                       ...actions,
                       const SizedBox(width: 4),

apps/todo/halkyon_todo_flutter/lib/src/tabs/today_tab.dart

@@ -67,8 +67,8 @@ class _TodayTabState() extends State<TodayTab> with PlanHost<TodayTab> {
     return TabScreen(
       title: l10n.shellTabToday,
       subtitle: state.loaded && count > 0 ? l10n.todayCount(count) : null,
+      leadingActions: [if (calendar) planButton(context, state, today)],
       actions: [
-        if (calendar) planButton(context, state, today),
         DisplayButton(target: todayDisplay),
         const SelectTasksMenu(),
       ],

apps/todo/halkyon_todo_flutter/lib/src/tabs/todo_shell.dart

@@ -4,6 +4,7 @@ import 'package:halkyon_todo_flutter/l10n/app_localizations.dart';
 import 'package:halkyon_todo_flutter/src/app/todo_frame.dart';
 import 'package:halkyon_todo_flutter/src/feature/task/widget/task_selection.dart';
 import 'package:halkyon_todo_flutter/src/feature/task/widget/task_sheet.dart';
+import 'package:halkyon_todo_flutter/src/tabs/navigation_bar_hold.dart';
 import 'package:halkyon_todo_flutter/src/tabs/today_icon.dart';
 import 'package:halkyon_ui/halkyon_ui.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
@@ -29,9 +30,13 @@ class _TodoShellState() extends State<TodoShell> {
   /// what to do with them takes the navigation bar's place.
   final _selection = TaskSelection();
 
+  /// Whoever holds the navigation bar away (a phone's Plan).
+  final _hold = NavigationBarHold();
+
   @override
   void dispose() {
     _selection.dispose();
+    _hold.dispose();
     super.dispose();
   }
 
@@ -42,13 +47,13 @@ class _TodoShellState() extends State<TodoShell> {
     return TaskSelectionScope(
       notifier: _selection,
       child: ListenableBuilder(
-        listenable: _selection,
+        listenable: Listenable.merge([_selection, _hold]),
         builder: (context, child) => WhatsNewOnUpdate(
           child: NavigationFrame(
             appName: l10n.appTitle,
             icon: todoIcon,
             selectedIndex: shell.currentIndex,
-            hidesNavigationBar: _selection.active,
+            hidesNavigationBar: _selection.active || _hold.held,
             // A tab chosen again goes back to its first screen; choosing tasks
             // ends with the tab.
             onSelected: (index) {
@@ -88,7 +93,10 @@ class _TodoShellState() extends State<TodoShell> {
           ),
         ),
         // From expanded windows on, a task opens beside the list (D2).
-        child: TaskPane(child: shell),
+        child: NavigationBarHoldScope(
+          notifier: _hold,
+          child: TaskPane(child: shell),
+        ),
       ),
     );
   }

apps/todo/halkyon_todo_flutter/lib/src/tabs/upcoming_tab.dart

@@ -78,9 +78,11 @@ class _UpcomingTabState()
     void select(Day day) => setState(() => _selected = day);
     return TabScreen(
       title: l10n.shellTabUpcoming,
-      actions: [
+      leadingActions: [
         if (upcoming.layout == UpcomingLayout.threeDay)
           planButton(context, state, today),
+      ],
+      actions: [
         DisplayButton(target: upcomingDisplay),
         const SelectTasksMenu(),
       ],

apps/todo/halkyon_todo_flutter/test/app/todo_app_test.dart

@@ -1963,6 +1963,12 @@ void main() {
         expect(find.byKey(UpcomingTab.planKey), findsNothing);
         await threeDay(tester);
         expect(find.byKey(UpcomingTab.planKey), findsOneWidget);
+        // Before search, Display and the menu every tab has (the
+        // developer's review, 7 Nov 2026).
+        expect(
+          tester.getTopRight(find.byKey(UpcomingTab.planKey)).dx,
+          lessThanOrEqualTo(tester.getTopLeft(find.byTooltip('Search')).dx),
+        );
         tester.view.physicalSize = const Size(1400, 900);
         await tester.pumpAndSettle();
         expect(find.text('No date'), findsOneWidget);
@@ -2690,6 +2696,76 @@ void main() {
         });
       });
 
+      testWidgets('on a phone, Plan stands before search, pointing down where '
+          'it opens; open, the navigation bar steps aside until it is '
+          'closed or back is pressed, its projects and close button at its '
+          "end (the developer's review, 7 Nov 2026)", (tester) async {
+        await start(tester, usedBefore: true);
+        // A wide phone, room to spare beside the heading's projects.
+        tester.view.physicalSize = const Size(560, 900);
+        await calendar(tester);
+        final plan = find.byKey(TodayTab.planKey);
+        final search = tester.getTopLeft(find.byTooltip('Search')).dx;
+        expect(tester.getTopRight(plan).dx, lessThanOrEqualTo(search));
+        expect(
+          search,
+          lessThan(tester.getTopLeft(find.byTooltip('Display')).dx),
+        );
+        expect(
+          find.descendant(
+            of: plan,
+            matching: find.byIcon(LucideIcons.panelBottomOpen),
+          ),
+          findsOneWidget,
+        );
+        expect(find.byType(NavigationBar), findsOneWidget);
+
+        await tester.tap(plan);
+        await tester.pumpAndSettle();
+        final sheet = find.byKey(TodayTab.planSheetKey);
+        expect(sheet, findsOneWidget);
+        expect(find.byType(NavigationBar), findsNothing);
+        expect(
+          find.descendant(
+            of: plan,
+            matching: find.byIcon(LucideIcons.panelBottomClose),
+          ),
+          findsOneWidget,
+        );
+        expect(
+          tester.getBottomLeft(sheet).dy,
+          900,
+          reason: 'down to the foot, no bar below it',
+        );
+
+        final close = find.ancestor(
+          of: find.descendant(
+            of: sheet,
+            matching: find.byTooltip('Hide the Plan'),
+          ),
+          matching: find.byType(IconButton),
+        );
+        expect(tester.getTopRight(close).dx, tester.getTopRight(sheet).dx - 4);
+        expect(
+          tester.getTopRight(find.byKey(PlanPanel.projectsKey)).dx,
+          moreOrLessEquals(tester.getTopLeft(close).dx, epsilon: 1),
+        );
+
+        await tester.tap(close);
+        await tester.pumpAndSettle();
+        expect(sheet, findsNothing);
+        expect(find.byType(NavigationBar), findsOneWidget);
+
+        await tester.tap(plan);
+        await tester.pumpAndSettle();
+        expect(find.byType(NavigationBar), findsNothing);
+        await tester.binding.handlePopRoute();
+        await tester.pumpAndSettle();
+        expect(sheet, findsNothing);
+        expect(find.byType(NavigationBar), findsOneWidget);
+        expect(find.byKey(TodayTab.planKey), findsOneWidget, reason: 'stays');
+      });
+
       testWidgets('on a phone, Plan opens a sheet over the day; a row held '
           'there lowers it out of the way and dropped on 14:00 is planned '
           'then', (tester) async {