Merge branch 'master' into scroll-by-wheel-speedup

Author: nikitatg

packages/scrollable_positioned_list/CHANGELOG.md

@@ -1,3 +1,9 @@
+# 0.3.5
+* Fix extraneous animation controller declaration in 0.3.4.
+
+# 0.3.4
+* Disposed the animation controller when disposing the scrollable list.
+
 # 0.3.3
 * Fix potential crash when reading from RenderBox.size.
 

packages/scrollable_positioned_list/lib/src/scrollable_positioned_list.dart

@@ -299,6 +299,8 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
   void _speedupClosureSecondary() =>
       _speedUpScrollListener(secondary.scrollController);
 
+  var _animationController;
+
   @override
   void initState() {
     super.initState();
@@ -330,6 +332,7 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
         .removeListener(_updatePositions);
     primary.scrollController.removeListener(_speedupClosurePrimary);
     secondary.scrollController.removeListener(_speedupClosureSecondary);
+    _animationController?.dispose();
     super.dispose();
   }
 
@@ -526,9 +529,11 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
       startAnimationCallback = () {
         SchedulerBinding.instance.addPostFrameCallback((_) {
           startAnimationCallback = () {};
-
-          opacity.parent = _opacityAnimation(opacityAnimationWeights).animate(
-              AnimationController(vsync: this, duration: duration)..forward());
+          _animationController?.dispose();
+          _animationController =
+              AnimationController(vsync: this, duration: duration)..forward();
+          opacity.parent = _opacityAnimation(opacityAnimationWeights)
+              .animate(_animationController);
           secondary.scrollController.jumpTo(-direction *
               (_screenScrollCount *
                       primary.scrollController.position.viewportDimension -
@@ -584,6 +589,19 @@ class _ScrollablePositionedListState extends State<ScrollablePositionedList>
       _isTransitioning = false;
       opacity.parent = const AlwaysStoppedAnimation<double>(0);
     });
+    if (mounted) {
+      setState(() {
+        if (opacity.value >= 0.5) {
+          // Secondary [ListView] is more visible than the primary; make it the
+          // new primary.
+          var temp = primary;
+          primary = secondary;
+          secondary = temp;
+        }
+        _isTransitioning = false;
+        opacity.parent = const AlwaysStoppedAnimation<double>(0);
+      });
+    }
   }
 
   Animatable<double> _opacityAnimation(List<double> opacityAnimationWeights) {

packages/scrollable_positioned_list/pubspec.yaml

@@ -1,5 +1,5 @@
 name: scrollable_positioned_list
-version: 0.3.3
+version: 0.3.5
 description: >
   A list with helper methods to programmatically scroll to an item.
 homepage: https://github.com/google/flutter.widgets/tree/master/packages/scrollable_positioned_list

packages/visibility_detector/CHANGELOG.md

@@ -1,5 +1,14 @@
 # CHANGELOG
 
+## 0.4.0+2
+
+* Fix a bug for updates to render objects that have not been laid out yet.
+
+## 0.4.0+1
+
+* Correct Flutter SDK version dependency to 3.1.0.
+* Replace use of deprecated APIs in the example for compatibility with Flutter v3.1.0.
+
 ## 0.4.0
 
 * Refactor to avoid forcing composition in the layer/render trees.

packages/visibility_detector/example/lib/main.dart

@@ -368,7 +368,10 @@ class DemoPageCell extends StatelessWidget {
       alignment: Alignment.center,
       child: FittedBox(
         fit: BoxFit.scaleDown,
-        child: Text(_cellName, style: Theme.of(context).textTheme.headline4),
+        child: Text(
+          _cellName,
+          style: Theme.of(context).textTheme.headlineMedium,
+        ),
       ),
     );
 
@@ -411,7 +414,7 @@ class VisibilityReport extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final headingTextStyle =
-        Theme.of(context).textTheme.headline6!.copyWith(color: Colors.white);
+        Theme.of(context).textTheme.titleLarge?.copyWith(color: Colors.white);
 
     final heading = Container(
       padding: const EdgeInsets.all(_reportPadding),

packages/visibility_detector/lib/src/render_visibility_detector.dart

@@ -140,7 +140,14 @@ mixin RenderVisibilityDetectorBase on RenderObject {
     }
     bool isFirstUpdate = _updates.isEmpty;
     _updates[key] = () {
-      _fireCallback(layer, bounds);
+      if (bounds == null) {
+        // This can happen if set onVisibilityChanged was called with a non-null
+        // value but this render object has not been laid out. In that case,
+        // it has no size or geometry, and we should not worry about firing
+        // an update since it never has been visible.
+        return;
+      }
+      _fireCallback(layer, bounds!);
     };
     final updateInterval = VisibilityDetectorController.instance.updateInterval;
     if (updateInterval == Duration.zero) {
@@ -228,7 +235,9 @@ mixin RenderVisibilityDetectorBase on RenderObject {
 
   /// Used to get the bounds of the render object when it is time to update
   /// clients about visibility.
-  Rect get bounds;
+  ///
+  /// A null value means bounds are not available.
+  Rect? get bounds;
 
   Matrix4? _lastPaintTransform;
   Rect? _lastPaintClipBounds;
@@ -280,7 +289,7 @@ class RenderVisibilityDetector extends RenderProxyBox
   final Key key;
 
   @override
-  Rect get bounds => semanticBounds;
+  Rect? get bounds => hasSize ? semanticBounds : null;
 }
 
 /// The [RenderObject] corresponding to the [SliverVisibilityDetector] widget.
@@ -302,7 +311,11 @@ class RenderSliverVisibilityDetector extends RenderProxySliver
   final Key key;
 
   @override
-  Rect get bounds {
+  Rect? get bounds {
+    if (geometry == null) {
+      return null;
+    }
+
     Size widgetSize;
     Offset widgetOffset;
     switch (applyGrowthDirectionToAxisDirection(

packages/visibility_detector/pubspec.yaml

@@ -1,12 +1,12 @@
 name: visibility_detector
-version: 0.4.0
+version: 0.4.0+2
 description: >
   A widget that detects the visibility of its child and notifies a callback.
 repository: https://github.com/google/flutter.widgets/tree/master/packages/visibility_detector
 
 environment:
   sdk: '>=2.12.0 <3.0.0'
-  flutter: '>=2.12.0'
+  flutter: '>=3.1.0-0'
 
 dependencies:
   flutter:

packages/visibility_detector/test/render_visibility_detector_test.dart

@@ -134,4 +134,44 @@ void main() {
 
     expect(detector.debugScheduleUpdateCount, 0);
   });
+
+  testWidgets('RVS can schedule an update for a RO that is not laid out',
+      (WidgetTester tester) async {
+    final RenderVisibilityDetector detector = RenderVisibilityDetector(
+      key: Key('test'),
+      onVisibilityChanged: (_) {
+        fail('should not get called');
+      },
+    );
+
+    // Force an out of band update to get scheduled without laying out.
+    detector.onVisibilityChanged = (_) {
+      fail('This should also not get called');
+    };
+
+    expect(detector.debugScheduleUpdateCount, 1);
+
+    detector.dispose();
+  });
+
+  testWidgets(
+      'RVS (Sliver) can schedule an update for a RO that is not laid out',
+      (WidgetTester tester) async {
+    final RenderSliverVisibilityDetector detector =
+        RenderSliverVisibilityDetector(
+      key: Key('test'),
+      onVisibilityChanged: (_) {
+        fail('should not get called');
+      },
+    );
+
+    // Force an out of band update to get scheduled without laying out.
+    detector.onVisibilityChanged = (_) {
+      fail('This should also not get called');
+    };
+
+    expect(detector.debugScheduleUpdateCount, 1);
+
+    detector.dispose();
+  });
 }