Fix DraggableScrollableSheet crash when switching out scrollables (#105549)
diff --git a/packages/flutter/lib/src/widgets/draggable_scrollable_sheet.dart b/packages/flutter/lib/src/widgets/draggable_scrollable_sheet.dart
index 9550969..a721548 100644
--- a/packages/flutter/lib/src/widgets/draggable_scrollable_sheet.dart
+++ b/packages/flutter/lib/src/widgets/draggable_scrollable_sheet.dart
@@ -631,7 +631,7 @@
@override
void didUpdateWidget(covariant DraggableScrollableSheet oldWidget) {
super.didUpdateWidget(oldWidget);
- _replaceExtent();
+ _replaceExtent(oldWidget);
}
@override
@@ -671,7 +671,7 @@
super.dispose();
}
- void _replaceExtent() {
+ void _replaceExtent(covariant DraggableScrollableSheet oldWidget) {
final _DraggableSheetExtent previousExtent = _extent;
_extent.dispose();
_extent = _extent.copyWith(
@@ -688,13 +688,21 @@
// If an external facing controller was provided, let it know that the
// extent has been replaced.
widget.controller?._onExtentReplaced(previousExtent);
- if (widget.snap) {
- // Trigger a snap in case snap or snapSizes has changed. We put this in a
- // post frame callback so that `build` can update `_extent.availablePixels`
- // before this runs-we can't use the previous extent's available pixels as
- // it may have changed when the widget was updated.
+ if (widget.snap
+ && (widget.snap != oldWidget.snap || widget.snapSizes != oldWidget.snapSizes)
+ && _scrollController.hasClients
+ ) {
+ // Trigger a snap in case snap or snapSizes has changed and there is a
+ // scroll position currently attached. We put this in a post frame
+ // callback so that `build` can update `_extent.availablePixels` before
+ // this runs-we can't use the previous extent's available pixels as it may
+ // have changed when the widget was updated.
WidgetsBinding.instance.addPostFrameCallback((Duration timeStamp) {
- _scrollController.position.goBallistic(0);
+ for (int index = 0; index < _scrollController.positions.length; index++) {
+ final _DraggableScrollableSheetScrollPosition position =
+ _scrollController.positions.elementAt(index) as _DraggableScrollableSheetScrollPosition;
+ position.goBallistic(0);
+ }
});
}
}
diff --git a/packages/flutter/test/widgets/draggable_scrollable_sheet_test.dart b/packages/flutter/test/widgets/draggable_scrollable_sheet_test.dart
index 1ac573e..8781f1f 100644
--- a/packages/flutter/test/widgets/draggable_scrollable_sheet_test.dart
+++ b/packages/flutter/test/widgets/draggable_scrollable_sheet_test.dart
@@ -745,6 +745,63 @@
await tester.pumpAndSettle();
}, variant: TargetPlatformVariant.all());
+ testWidgets('Transitioning between scrollable children sharing a scroll controller will not throw', (WidgetTester tester) async {
+ int s = 0;
+ await tester.pumpWidget(MaterialApp(
+ home: StatefulBuilder(
+ builder: (BuildContext context, StateSetter setState) {
+ return Scaffold(
+ body: DraggableScrollableSheet(
+ initialChildSize: 0.25,
+ snap: true,
+ snapSizes: const <double>[0.25, 0.5, 1.0],
+ builder: (BuildContext context, ScrollController scrollController) {
+ return PrimaryScrollController(
+ controller: scrollController,
+ child: AnimatedSwitcher(
+ duration: const Duration(milliseconds: 500),
+ child: (s.isEven)
+ ? ListView(
+ children: <Widget>[
+ ElevatedButton(
+ onPressed: () => setState(() => ++s),
+ child: const Text('Switch to 2'),
+ ),
+ Container(
+ height: 400,
+ color: Colors.blue,
+ ),
+ ],
+ )
+ : SingleChildScrollView(
+ child: Column(
+ children: <Widget>[
+ ElevatedButton(
+ onPressed: () => setState(() => ++s),
+ child: const Text('Switch to 1'),
+ ),
+ Container(
+ height: 400,
+ color: Colors.blue,
+ ),
+ ],
+ )
+ ),
+ ),
+ );
+ },
+ ),
+ );
+ },
+ ),
+ ));
+
+ // Trigger the AnimatedSwitcher between ListViews
+ await tester.tap(find.text('Switch to 2'));
+ await tester.pump();
+ // Completes without throwing
+ });
+
testWidgets('ScrollNotification correctly dispatched when flung without covering its container', (WidgetTester tester) async {
final List<Type> notificationTypes = <Type>[];
await tester.pumpWidget(boilerplateWidget(
