Fix a scrollbar crash bug (#92657)
diff --git a/packages/flutter/lib/src/widgets/scrollbar.dart b/packages/flutter/lib/src/widgets/scrollbar.dart
index 0b15886..28c951d 100644
--- a/packages/flutter/lib/src/widgets/scrollbar.dart
+++ b/packages/flutter/lib/src/widgets/scrollbar.dart
@@ -607,6 +607,8 @@
return _paintScrollbar(canvas, size, thumbExtent, _lastAxisDirection!);
}
+ bool get _lastMetricsAreScrollable => _lastMetrics!.minScrollExtent != _lastMetrics!.maxScrollExtent;
+
/// Same as hitTest, but includes some padding when the [PointerEvent] is
/// caused by [PointerDeviceKind.touch] to make sure that the region
/// isn't too small to be interacted with by the user.
@@ -617,12 +619,16 @@
/// based on proximity. When `forHover` is true, the larger hit test area will
/// be used.
bool hitTestInteractive(Offset position, PointerDeviceKind kind, { bool forHover = false }) {
- if (_thumbRect == null) {
+ if (_trackRect == null) {
// We have not computed the scrollbar position yet.
return false;
}
- final Rect interactiveRect = _trackRect ?? _thumbRect!;
+ if (!_lastMetricsAreScrollable) {
+ return false;
+ }
+
+ final Rect interactiveRect = _trackRect!;
final Rect paddedRect = interactiveRect.expandToInclude(
Rect.fromCircle(center: _thumbRect!.center, radius: _kMinInteractiveSize / 2),
);
@@ -658,6 +664,10 @@
return false;
}
+ if (!_lastMetricsAreScrollable) {
+ return false;
+ }
+
switch (kind) {
case PointerDeviceKind.touch:
final Rect touchThumbRect = _thumbRect!.expandToInclude(
@@ -682,6 +692,11 @@
if (fadeoutOpacityAnimation.value == 0.0) {
return false;
}
+
+ if (!_lastMetricsAreScrollable) {
+ return false;
+ }
+
return _thumbRect!.contains(position!);
}
@@ -1347,6 +1362,7 @@
void _updateScrollPosition(Offset updatedOffset) {
assert(_currentController != null);
assert(_dragScrollbarAxisOffset != null);
+
final ScrollPosition position = _currentController!.position;
late double primaryDelta;
switch (position.axisDirection) {
diff --git a/packages/flutter/test/widgets/scrollbar_test.dart b/packages/flutter/test/widgets/scrollbar_test.dart
index c7f3433..c890049 100644
--- a/packages/flutter/test/widgets/scrollbar_test.dart
+++ b/packages/flutter/test/widgets/scrollbar_test.dart
@@ -2038,6 +2038,43 @@
expect(depths[1], 0);
});
+ // Regression test for https://github.com/flutter/flutter/issues/92262
+ testWidgets('Do not crash when resize from scrollable to non-scrollable.', (WidgetTester tester) async {
+ final ScrollController scrollController = ScrollController();
+ Widget buildFrame(double height) {
+ return Directionality(
+ textDirection: TextDirection.ltr,
+ child: MediaQuery(
+ data: const MediaQueryData(),
+ child: RawScrollbar(
+ controller: scrollController,
+ interactive: true,
+ isAlwaysShown: true,
+ child: SingleChildScrollView(
+ controller: scrollController,
+ child: Container(
+ width: 100.0,
+ height: height,
+ color: const Color(0xFF000000),
+ ),
+ ),
+ ),
+ ),
+ );
+ }
+ await tester.pumpWidget(buildFrame(700.0));
+ await tester.pumpAndSettle();
+
+ await tester.pumpWidget(buildFrame(600.0));
+ await tester.pumpAndSettle();
+
+ // Try to drag the thumb.
+ final TestGesture dragScrollbarGesture = await tester.startGesture(const Offset(798.0, 5.0));
+ await tester.pumpAndSettle();
+ await dragScrollbarGesture.moveBy(const Offset(0.0, 5.0));
+ await tester.pumpAndSettle();
+ });
+
test('ScrollbarPainter.shouldRepaint returns true when any of the properties changes', () {
ScrollbarPainter createPainter({
Color color = const Color(0xFF000000),
