fix(superdeck): release capture resources and prune stale thumbnails

.github/workflows/test.yml

@@ -5,7 +5,6 @@ on:
   push:
     branches: [main]
   pull_request:
-    branches: [main]
 
 concurrency:
   group: test-${{ github.ref }}
@@ -17,13 +16,13 @@ jobs:
     name: Test
     timeout-minutes: 12
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Install FVM
         shell: bash
         run: |
           curl -fsSL https://fvm.app/install.sh | bash
-          echo "/home/runner/fvm/bin" >> $GITHUB_PATH
+          echo "/home/runner/fvm/bin" >> "$GITHUB_PATH"
 
       - uses: kuhnroyal/flutter-fvm-config-action@v2
         id: fvm-config-action
@@ -71,7 +70,7 @@ jobs:
     name: Integration Tests
     timeout-minutes: 25
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Install Linux Desktop Dependencies
         timeout-minutes: 8
@@ -87,7 +86,7 @@ jobs:
         shell: bash
         run: |
           curl -fsSL https://fvm.app/install.sh | bash
-          echo "/home/runner/fvm/bin" >> $GITHUB_PATH
+          echo "/home/runner/fvm/bin" >> "$GITHUB_PATH"
 
       - uses: kuhnroyal/flutter-fvm-config-action@v2
         id: fvm-config-action
@@ -137,7 +136,7 @@ jobs:
         shell: bash
         run: |
           curl -fsSL https://fvm.app/install.sh | bash
-          echo "/home/runner/fvm/bin" >> $GITHUB_PATH
+          echo "/home/runner/fvm/bin" >> "$GITHUB_PATH"
 
       - uses: kuhnroyal/flutter-fvm-config-action@v2
         id: fvm-config-action

packages/superdeck/lib/src/capture/slide_capture_service.dart

@@ -206,19 +206,33 @@ class SlideCaptureService {
   }
 
   Future<Uint8List> _imageToUint8List(ui.Image image) async {
-    final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
-    image.dispose();
-    return byteData!.buffer.asUint8List();
+    try {
+      final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
+
+      return byteData!.buffer.asUint8List();
+    } finally {
+      image.dispose();
+    }
   }
 
   /// Converts a Flutter widget to a [ui.Image] via an isolated render pipeline.
   ///
   /// Sets up a complete render context (theme, media query, material app),
   /// drives a bounded settle loop for async/delayed widgets, then rasterises.
+  /// Releases the temporary element, render, and focus resources on success,
+  /// on the settle limit, and on failure.
   Future<ui.Image> _fromWidgetToImage(
     Widget widget,
     RenderConfig config,
   ) async {
+    RenderRepaintBoundary? repaintBoundary;
+    RenderPositionedBox? rootBox;
+    RenderView? renderView;
+    PipelineOwner? pipelineOwner;
+    FocusManager? focusManager;
+    BuildOwner? buildOwner;
+    RenderObjectToWidgetElement<RenderBox>? rootElement;
+
     try {
       final mixScope = MixScope.maybeOf(config.context);
       final readiness = SlideCaptureReadiness();
@@ -242,7 +256,11 @@ class SlideCaptureService {
         ),
       );
 
-      final repaintBoundary = RenderRepaintBoundary();
+      repaintBoundary = RenderRepaintBoundary();
+      rootBox = RenderPositionedBox(
+        alignment: Alignment.center,
+        child: repaintBoundary,
+      );
       final platformDispatcher = WidgetsBinding.instance.platformDispatcher;
 
       final view =
@@ -251,12 +269,9 @@ class SlideCaptureService {
           config.targetSize ?? view.physicalSize / view.devicePixelRatio;
       final physicalSize = logicalSize * config.pixelRatio;
 
-      final renderView = RenderView(
+      renderView = RenderView(
         view: view,
-        child: RenderPositionedBox(
-          alignment: Alignment.center,
-          child: repaintBoundary,
-        ),
+        child: rootBox,
         configuration: ViewConfiguration(
           logicalConstraints: BoxConstraints.tight(logicalSize),
           physicalConstraints: BoxConstraints.tight(physicalSize),
@@ -265,18 +280,17 @@ class SlideCaptureService {
       );
 
       var isDirty = false;
-      final pipelineOwner = PipelineOwner(
-        onNeedVisualUpdate: () => isDirty = true,
-      );
-      final buildOwner = BuildOwner(
-        focusManager: FocusManager(),
+      pipelineOwner = PipelineOwner(onNeedVisualUpdate: () => isDirty = true);
+      focusManager = FocusManager();
+      buildOwner = BuildOwner(
+        focusManager: focusManager,
         onBuildScheduled: () => isDirty = true,
       );
 
       pipelineOwner.rootNode = renderView;
       renderView.prepareInitialFrame();
 
-      final rootElement = RenderObjectToWidgetAdapter<RenderBox>(
+      rootElement = RenderObjectToWidgetAdapter<RenderBox>(
         container: repaintBoundary,
         child: Directionality(textDirection: TextDirection.ltr, child: child),
       ).attachToRenderTree(buildOwner);
@@ -331,6 +345,61 @@ class SlideCaptureService {
     } catch (e) {
       log('Error finalizing tree: $e');
       rethrow;
+    } finally {
+      _releaseCaptureTree(
+        buildOwner: buildOwner,
+        rootElement: rootElement,
+        repaintBoundary: repaintBoundary,
+        rootBox: rootBox,
+        renderView: renderView,
+        pipelineOwner: pipelineOwner,
+        focusManager: focusManager,
+      );
+    }
+  }
+
+  /// Unmounts the temporary capture subtree and releases its owned resources.
+  ///
+  /// Rebuilding the root adapter without a child deactivates the captured
+  /// widgets, and [BuildOwner.finalizeTree] then unmounts them so their
+  /// [State.dispose] and render object disposal run. The render pipeline,
+  /// the render objects this service created, and the focus manager are
+  /// released afterwards.
+  void _releaseCaptureTree({
+    required BuildOwner? buildOwner,
+    required RenderObjectToWidgetElement<RenderBox>? rootElement,
+    required RenderRepaintBoundary? repaintBoundary,
+    required RenderPositionedBox? rootBox,
+    required RenderView? renderView,
+    required PipelineOwner? pipelineOwner,
+    required FocusManager? focusManager,
+  }) {
+    if (buildOwner != null && rootElement != null && repaintBoundary != null) {
+      try {
+        RenderObjectToWidgetAdapter<RenderBox>(
+          container: repaintBoundary,
+        ).attachToRenderTree(buildOwner, rootElement);
+        buildOwner
+          ..buildScope(rootElement)
+          ..finalizeTree();
+      } catch (e, stackTrace) {
+        log('Error unmounting capture tree: $e', stackTrace: stackTrace);
+      }
+    }
+
+    if (pipelineOwner != null) {
+      pipelineOwner.rootNode = null;
+      pipelineOwner.dispose();
+    }
+
+    repaintBoundary?.dispose();
+    rootBox?.dispose();
+    renderView?.dispose();
+
+    if (focusManager != null) {
+      // Unmounting focus nodes schedules a focus update microtask. Disposing
+      // in a later microtask lets that update run against a live manager.
+      scheduleMicrotask(focusManager.dispose);
     }
   }
 }

packages/superdeck/lib/src/deck/deck_presentation_state.dart

@@ -19,6 +19,8 @@ final class DeckPresentationState {
   final _thumbnails = signal<Map<String, AsyncThumbnail>>({});
 
   EffectCleanup? _indexClampEffect;
+  EffectCleanup? _thumbnailPruneEffect;
+  int _transitionOperation = 0;
   bool _disposed = false;
 
   late final GoRouter router = GoRouter(
@@ -57,6 +59,11 @@ final class DeckPresentationState {
         _currentIndex.value = clamped;
       }
     });
+    // Thumbnail cleanup follows the slide collection, not thumbnail warmup,
+    // so obsolete handles are released even when the deck becomes empty.
+    _thumbnailPruneEffect = effect(() {
+      _pruneThumbnails(_slideKeys(_slides.value));
+    });
   }
 
   ReadonlySignal<bool> get isMenuOpen => _isMenuOpen;
@@ -96,10 +103,13 @@ final class DeckPresentationState {
 
   Future<void> goToSlide(int index) async {
     if (_disposed || index < 0 || index >= _slides.value.length) return;
+    // Only the latest transition may clear the transitioning state, so an
+    // earlier delay cannot end a transition that started after it.
+    final operation = ++_transitionOperation;
     _isTransitioning.value = true;
     router.go('/slides/$index');
     await Future<void>.delayed(_transitionDuration);
-    if (_disposed) return;
+    if (_disposed || operation != _transitionOperation) return;
     _isTransitioning.value = false;
   }
 
@@ -121,28 +131,14 @@ final class DeckPresentationState {
     bool force = false,
   }) {
     if (_disposed) return;
-    if (slides.isEmpty) return;
-
-    final validKeys = slides.map((s) => s.key).toSet();
-    final current = _thumbnails.value;
-    final staleKeys = current.keys
-        .where((k) => !validKeys.contains(k))
-        .toList(growable: false);
-    final cache = staleKeys.isEmpty
-        ? current
-        : Map<String, AsyncThumbnail>.from(current);
 
-    for (final key in staleKeys) {
-      cache.remove(key)?.dispose();
-    }
-    if (staleKeys.isNotEmpty) {
-      _thumbnails.value = cache;
-    }
+    _pruneThumbnails(_slideKeys(slides));
+    if (slides.isEmpty) return;
 
     _thumbnailService.generateThumbnails(
       slides: slides,
       context: context,
-      cache: cache,
+      cache: _thumbnails.peek(),
       onCacheUpdate: (updated) {
         if (_disposed) return;
         _thumbnails.value = updated;
@@ -174,6 +170,7 @@ final class DeckPresentationState {
   void dispose() {
     _disposed = true;
     _indexClampEffect?.call();
+    _thumbnailPruneEffect?.call();
     router.routeInformationProvider.removeListener(_syncCurrentIndexFromRouter);
     router.dispose();
     for (final thumbnail in _thumbnails.value.values) {
@@ -190,6 +187,23 @@ final class DeckPresentationState {
     currentSlide.dispose();
   }
 
+  /// Disposes and drops every thumbnail whose slide is no longer present.
+  void _pruneThumbnails(Set<String> validKeys) {
+    if (_disposed) return;
+
+    final current = _thumbnails.peek();
+    final staleKeys = current.keys
+        .where((key) => !validKeys.contains(key))
+        .toList(growable: false);
+    if (staleKeys.isEmpty) return;
+
+    final cache = Map<String, AsyncThumbnail>.from(current);
+    for (final key in staleKeys) {
+      cache.remove(key)?.dispose();
+    }
+    _thumbnails.value = cache;
+  }
+
   void _syncCurrentIndexFromRouter() {
     if (_disposed) return;
     final path = router.routeInformationProvider.value.uri.path;
@@ -205,6 +219,9 @@ final class DeckPresentationState {
     }
   }
 
+  static Set<String> _slideKeys(List<SlideConfiguration> slides) =>
+      slides.map((slide) => slide.key).toSet();
+
   static int _clampIndex(int index, int totalSlides) {
     final maxIndex = totalSlides > 0 ? totalSlides - 1 : 0;
     return index.clamp(0, maxIndex);