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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';
void main() {
testWidgets('TrackingScrollController saves offset', (WidgetTester tester) async {
final TrackingScrollController controller = TrackingScrollController();
const double listItemHeight = 100.0;
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: PageView.builder(
itemBuilder: (BuildContext context, int index) {
return ListView(
controller: controller,
children: List<Widget>.generate(
10,
(int i) => SizedBox(
height: listItemHeight,
child: Text('Page$index-Item$i'),
),
).toList(),
);
},
),
),
);
expect(find.text('Page0-Item1'), findsOneWidget);
expect(find.text('Page1-Item1'), findsNothing);
expect(find.text('Page2-Item0'), findsNothing);
expect(find.text('Page2-Item1'), findsNothing);
controller.jumpTo(listItemHeight + 10);
await tester.pumpAndSettle();
await tester.fling(find.text('Page0-Item1'), const Offset(-100.0, 0.0), 10000.0);
await tester.pumpAndSettle();
expect(find.text('Page0-Item1'), findsNothing);
expect(find.text('Page1-Item1'), findsOneWidget);
expect(find.text('Page2-Item0'), findsNothing);
expect(find.text('Page2-Item1'), findsNothing);
await tester.fling(find.text('Page1-Item1'), const Offset(-100.0, 0.0), 10000.0);
await tester.pumpAndSettle();
expect(find.text('Page0-Item1'), findsNothing);
expect(find.text('Page1-Item1'), findsNothing);
expect(find.text('Page2-Item0'), findsNothing);
expect(find.text('Page2-Item1'), findsOneWidget);
await tester.pumpWidget(const Text('Another page', textDirection: TextDirection.ltr));
expect(controller.initialScrollOffset, 0.0);
});
}