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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
class Foo extends StatefulWidget {
const Foo({ super.key });
@override
FooState createState() => FooState();
}
class FooState extends State<Foo> {
ScrollController scrollController = ScrollController();
@override
Widget build(BuildContext context) {
return LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
return ScrollConfiguration(
behavior: const FooScrollBehavior(),
child: ListView(
controller: scrollController,
children: <Widget>[
GestureDetector(
onTap: () {
setState(() { /* this is needed to trigger the original bug this is regression-testing */ });
scrollController.animateTo(200.0, duration: const Duration(milliseconds: 500), curve: Curves.linear);
},
child: const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
),
const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
const DecoratedBox(
decoration: BoxDecoration(color: Color(0x00000000)),
child: SizedBox(
height: 200.0,
),
),
],
),
);
},
);
}
}
class FooScrollBehavior extends ScrollBehavior {
const FooScrollBehavior();
@override
bool shouldNotify(FooScrollBehavior old) => true;
}
void main() {
testWidgets('Can animate scroll after setState', (WidgetTester tester) async {
await tester.pumpWidget(
const Directionality(
textDirection: TextDirection.ltr,
child: Foo(),
),
);
expect(tester.state<ScrollableState>(find.byType(Scrollable)).position.pixels, 0.0);
await tester.tap(find.byType(GestureDetector).first);
await tester.pumpAndSettle();
expect(tester.state<ScrollableState>(find.byType(Scrollable)).position.pixels, 200.0);
});
}