fix(cards): the browser's actions end at the row's end; phones choose in the grid

From the expanded window on, what can be done to the chosen cards (Move,
Add tags, Delete, …, Done) stood short of the row's end: Select all and
Deselect all were flexible beside a spacer, so Flutter shared the room
between the three and the spacer got a third. Choosing now takes the room
the actions leave, in a row of its own.

On a phone the detail view (a card above a strip) had no way to choose a
card: a tap opened the composer even while choosing. Choosing cards now
shows the grid, where each card shows whether it is chosen, whichever view
was picked, and Done returns to it; the switch between them is off
meanwhile.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMm7usAo6q9ZZRoPkWjoxi
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/lib/src/feature/card/widget/card_browser_screen.dart

@@ -331,8 +331,9 @@ class _BrowserState() extends State<_Browser> {
             crossAxisAlignment: CrossAxisAlignment.stretch,
             children: [
               _Toolbar(
-                detailed: detailed,
+                detailed: detailed && !state.selecting,
-                onDetailed: _setDetailed,
+                // Choosing cards is the grid's: the view comes back after.
+                onDetailed: state.selecting ? null : _setDetailed,
                 searching: _searchOpen || state.filter.query.isNotEmpty,
                 onSearch: _toggleSearch,
                 sort: state.sort,
@@ -368,7 +369,9 @@ class _BrowserState() extends State<_Browser> {
               Expanded(
                 child: state.shown.isEmpty
                     ? _NoMatches(onClear: _clearFilters)
-                    : detailed
+                    // Cards are chosen in the grid, where each shows whether
+                    // it is chosen; the detail's tap opens a card.
+                    : detailed && !state.selecting
                     ? _Detail(
                         cards: state.shown,
                         current: _current,
@@ -498,7 +501,9 @@ typedef _Actions = ({
 /// and choosing cards, each tinted while it is at work.
 class const _Toolbar({
   required final bool detailed,
-  required final ValueChanged<bool> onDetailed,
+
+  /// Switches between grid and detail; off while cards are chosen.
+  required final ValueChanged<bool>? onDetailed,
   required final bool searching,
   required final VoidCallback onSearch,
   required final CardBrowserSort sort,
@@ -541,7 +546,10 @@ class const _Toolbar({
               ),
             ],
             selected: {detailed},
-            onSelectionChanged: (chosen) => onDetailed(chosen.single),
+            onSelectionChanged: switch (onDetailed) {
+              final change? => (chosen) => change(chosen.single),
+              null => null,
+            },
           ),
           const Spacer(),
           IconButton(
@@ -1289,42 +1297,48 @@ class const _SelectionControls({
         children: [
           Row(
             children: [
-              // On a narrow phone, in a longer language, they shorten.
+              // Choosing, at the start, takes the room the actions leave,
-              Flexible(
+              // so they end at the row's end: beside them, its flexible
-                child: TextButton(
+              // buttons would each claim a share of the room and leave it
-                  onPressed: all
+              // unused.
-                      ? null
+              Expanded(
-                      : () => context.read<CardBrowserBloc>().add(
+                child: Row(
-                          const CardBrowserEventAllSelected(),
+                  children: [
+                    // On a narrow phone, in a longer language, they shorten.
+                    Flexible(
+                      child: TextButton(
+                        onPressed: all
+                            ? null
+                            : () => context.read<CardBrowserBloc>().add(
+                                const CardBrowserEventAllSelected(),
+                              ),
+                        child: Text(
+                          l10n.cardBrowserSelectAll,
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis,
                         ),
-                  child: Text(
+                      ),
-                    l10n.cardBrowserSelectAll,
+                    ),
-                    maxLines: 1,
+                    Flexible(
-                    overflow: TextOverflow.ellipsis,
+                      child: TextButton(
-                  ),
+                        onPressed: selected == 0
+                            ? null
+                            : () => context.read<CardBrowserBloc>().add(
+                                const CardBrowserEventAllDeselected(),
+                              ),
+                        child: Text(
+                          l10n.cardBrowserDeselectAll,
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis,
+                        ),
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    _CountPill(count: selected),
+                  ],
                 ),
               ),
-              Flexible(
+              if (actions != null) ...[
-                child: TextButton(
-                  onPressed: selected == 0
-                      ? null
-                      : () => context.read<CardBrowserBloc>().add(
-                          const CardBrowserEventAllDeselected(),
-                        ),
-                  child: Text(
-                    l10n.cardBrowserDeselectAll,
-                    maxLines: 1,
-                    overflow: TextOverflow.ellipsis,
-                  ),
-                ),
-              ),
-              if (actions == null) ...[
-                const SizedBox(width: 8),
-                _CountPill(count: selected),
-              ] else ...[
-                const SizedBox(width: 8),
-                _CountPill(count: selected),
-                const Spacer(),
                 OutlinedButton.icon(
                   onPressed: actions.move,
                   icon: const Icon(LucideIcons.folderInput, size: 18),

halkyon_learn_flutter/test/feature/card/widget/card_browser_screen_test.dart

@@ -3,6 +3,7 @@ import 'package:halkyon_learn_flutter/src/core/content/rich_content.dart';
 import 'package:halkyon_learn_flutter/src/core/router/route_paths.dart';
 import 'package:halkyon_learn_flutter/src/feature/card/data/card_repository.dart';
 import 'package:halkyon_learn_flutter/src/feature/card/model/card_content.dart';
+import 'package:halkyon_learn_flutter/src/feature/card/widget/composer/card_composer_screen.dart';
 import 'package:halkyon_learn_flutter/src/feature/studyset/data/studyset_payload.dart';
 import 'package:halkyon_learn_flutter/src/feature/studyset/model/studyset_content.dart';
 import 'package:material_ui/material_ui.dart';
@@ -277,4 +278,36 @@ void main() {
     expect(find.byType(PageView), findsOneWidget);
     expect(find.byTooltip('Next'), findsNothing);
   });
+
+  testWidgets('from the expanded window on, what can be done to the chosen '
+      "cards ends at the row's end", (tester) async {
+    await show(tester);
+
+    await tester.tap(find.byTooltip('Select'));
+    await tester.pumpAndSettle();
+
+    final done = tester.getRect(find.widgetWithText(FilledButton, 'Done'));
+    final row = tester.getRect(find.byTooltip('Select').first);
+    expect(done.right, moreOrLessEquals(row.right, epsilon: 4));
+  });
+
+  testWidgets('on a phone in the detail view, choosing cards shows the '
+      'grid, where a tap chooses a card rather than opening it; Done '
+      'returns to the detail', (tester) async {
+    await show(tester, width: 400);
+    await tester.tap(find.byTooltip('Detail'));
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.byTooltip('Select'));
+    await tester.pumpAndSettle();
+    expect(find.byType(PageView), findsNothing);
+    await tester.tap(find.text('cat'));
+    await tester.pumpAndSettle();
+    expect(find.text('1 selected'), findsOneWidget);
+    expect(find.byType(CardComposerScreen), findsNothing);
+
+    await tester.tap(find.text('Done'));
+    await tester.pumpAndSettle();
+    expect(find.byType(PageView), findsOneWidget);
+  });
 }