Add Ctrl/Cmd+O open shortcut and bulk copy-slides-to-another-deck

- Bind Ctrl/Cmd+O app-wide to the open-presentation dialog (was unbound).
- Add a "copy to another deck" bulk action to the slide list: with multiple
  slides selected, pick a target open tab; the slides are appended there as
  fresh copies, leaving the source deck untouched. Multi-select, bulk delete
  and bulk skip/show already existed.

Test: cross-deck copy keeps the source intact and assigns fresh ids.

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

lib/widgets/app_shell.dart

@@ -299,6 +299,12 @@ class _AppShellState extends ConsumerState<AppShell> with WindowListener {
     );
   }
 
+  /// Open een presentatie via de zoek-/kies-dialoog. App-breed zodat Ctrl/Cmd+O
+  /// altijd werkt, ongeacht waar de focus zit.
+  void _openActive() {
+    _openWithSearch(context, ref, ref.read(settingsProvider).homeDirectory);
+  }
+
   bool _dragging = false;
 
   static const _imageExtensions = {
@@ -370,6 +376,9 @@ class _AppShellState extends ConsumerState<AppShell> with WindowListener {
         const SingleActivator(LogicalKeyboardKey.keyS, control: true):
             _saveActive,
         const SingleActivator(LogicalKeyboardKey.keyS, meta: true): _saveActive,
+        const SingleActivator(LogicalKeyboardKey.keyO, control: true):
+            _openActive,
+        const SingleActivator(LogicalKeyboardKey.keyO, meta: true): _openActive,
       },
       child: FocusScope(
         autofocus: true,

lib/widgets/panels/slide_list_panel.dart

@@ -7,6 +7,7 @@ import '../../models/slide.dart';
 import '../../state/deck_provider.dart';
 import '../../state/editor_provider.dart';
 import '../../state/settings_provider.dart';
+import '../../state/tabs_provider.dart';
 import '../../services/image_service.dart';
 import '../../services/slide_rasterizer.dart';
 import '../../state/slide_clipboard_provider.dart';
@@ -174,8 +175,7 @@ class _SlideListPanelState extends ConsumerState<SlideListPanel> {
     } catch (_) {}
     if (!mounted) return;
     final ok =
-        bytes != null &&
-        await ImageService().copyImageBytesToClipboard(bytes);
+        bytes != null && await ImageService().copyImageBytesToClipboard(bytes);
     if (!mounted) return;
     messenger.hideCurrentSnackBar();
     messenger.showSnackBar(
@@ -187,6 +187,78 @@ class _SlideListPanelState extends ConsumerState<SlideListPanel> {
     );
   }
 
+  /// De geselecteerde slides, op volgorde van positie in het deck.
+  List<Slide> _selectedSlides(Deck deck) {
+    final indices = ref.read(editorProvider).selection.toList()..sort();
+    return [
+      for (final i in indices)
+        if (i >= 0 && i < deck.slides.length) deck.slides[i],
+    ];
+  }
+
+  /// Kopieer de geselecteerde slides (bulk) naar een ander open deck. Toont een
+  /// keuzelijst van de overige open tabbladen; de slides worden achteraan dat
+  /// deck toegevoegd (met nieuwe id's, zodat het kopieën zijn).
+  Future<void> _copySelectionToOtherDeck() async {
+    final deck = ref.read(deckProvider).deck;
+    if (deck == null) return;
+    final slides = _selectedSlides(deck);
+    if (slides.isEmpty) return;
+
+    final tabs = ref.read(tabsProvider);
+    final currentId = tabs.current?.id;
+    final targets = tabs.tabs
+        .where((t) => t.id != currentId && t.isOpen)
+        .toList();
+
+    final messenger = ScaffoldMessenger.of(context);
+    if (targets.isEmpty) {
+      messenger.showSnackBar(
+        const SnackBar(
+          content: Text('Geen ander deck open. Open eerst een ander tabblad.'),
+        ),
+      );
+      return;
+    }
+
+    final target = await showDialog<TabInfo>(
+      context: context,
+      builder: (ctx) => SimpleDialog(
+        title: Text(
+          slides.length == 1
+              ? '1 slide kopiëren naar…'
+              : '${slides.length} slides kopiëren naar…',
+        ),
+        children: [
+          for (final t in targets)
+            SimpleDialogOption(
+              onPressed: () => Navigator.pop(ctx, t),
+              child: Row(
+                children: [
+                  const Icon(Icons.slideshow_outlined, size: 16),
+                  const SizedBox(width: 8),
+                  Expanded(child: Text(t.label)),
+                ],
+              ),
+            ),
+        ],
+      ),
+    );
+    if (target == null || !mounted) return;
+
+    final at = target.deckNotifier.insertSlides(slides);
+    if (!mounted) return;
+    messenger.showSnackBar(
+      SnackBar(
+        content: Text(
+          at >= 0
+              ? '${slides.length} slide(s) gekopieerd naar “${target.label}”.'
+              : 'Kopiëren mislukt.',
+        ),
+      ),
+    );
+  }
+
   /// Verwijder alle geselecteerde slides (bulk). Houdt minstens één over.
   void _deleteSelection() {
     final deck = ref.read(deckProvider).deck;
@@ -498,6 +570,7 @@ class _SlideListPanelState extends ConsumerState<SlideListPanel> {
                       const SizedBox(height: 6),
                       _BulkActionBar(
                         count: editor.selection.length,
+                        onCopyToDeck: _copySelectionToOtherDeck,
                         onDelete: _deleteSelection,
                         onSkip: () => notifier.setSkippedForSlides(
                           editor.selection,
@@ -780,6 +853,7 @@ class _SkipBanner extends StatelessWidget {
 
 class _BulkActionBar extends StatelessWidget {
   final int count;
+  final VoidCallback onCopyToDeck;
   final VoidCallback onDelete;
   final VoidCallback onSkip;
   final VoidCallback onShow;
@@ -787,6 +861,7 @@ class _BulkActionBar extends StatelessWidget {
 
   const _BulkActionBar({
     required this.count,
+    required this.onCopyToDeck,
     required this.onDelete,
     required this.onSkip,
     required this.onShow,
@@ -814,6 +889,11 @@ class _BulkActionBar extends StatelessWidget {
               ),
             ),
           ),
+          _BulkIcon(
+            icon: Icons.drive_file_move_outline,
+            tooltip: 'Kopiëren naar ander deck',
+            onTap: onCopyToDeck,
+          ),
           _BulkIcon(
             icon: Icons.visibility_off_outlined,
             tooltip: 'Overslaan bij presenteren/exporteren',

test/deck_provider_test.dart

@@ -61,6 +61,34 @@ void main() {
     expect(n.state.deck!.slides[1].id, isNot(source.id));
   });
 
+  test('copying a selection into another deck leaves the source intact', () {
+    // Source deck with three slides; "select" indices 0 and 2.
+    final source = _notifier()..newDeck('Bron');
+    source.addSlide(SlideType.bullets); // 1
+    source.addSlide(SlideType.image); // 2
+    final picked = [source.state.deck!.slides[0], source.state.deck!.slides[2]];
+    final sourceIdsBefore = source.state.deck!.slides.map((s) => s.id).toList();
+
+    // Target deck receives the copies (appended at the end).
+    final target = _notifier()..newDeck('Doel');
+    final at = target.insertSlides(picked);
+
+    expect(at, 1); // appended after the single title slide
+    expect(target.state.deck!.slides, hasLength(3));
+    expect(target.state.deck!.slides[1].type, SlideType.title);
+    expect(target.state.deck!.slides[2].type, SlideType.image);
+    // Copies must have fresh ids, not the source ids.
+    expect(
+      target.state.deck!.slides[1].id,
+      isNot(anyOf(picked.map((s) => s.id))),
+    );
+    // The source deck is untouched.
+    expect(
+      source.state.deck!.slides.map((s) => s.id).toList(),
+      sourceIdsBefore,
+    );
+  });
+
   test('reorderSlides moves a slide to a new position', () {
     final n = _notifier()..newDeck('D');
     n.addSlide(SlideType.bullets); // 1