| // Copyright 2015 The Chromium 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 'dart:async'; |
| |
| import 'package:meta/meta.dart'; |
| import 'package:flutter_test/flutter_test.dart'; |
| import 'package:flutter/material.dart'; |
| |
| ScrollController _controller = new ScrollController( |
| initialScrollOffset: 110.0, |
| ); |
| |
| class ThePositiveNumbers extends StatelessWidget { |
| const ThePositiveNumbers({ @required this.from }); |
| final int from; |
| @override |
| Widget build(BuildContext context) { |
| return new ListView.builder( |
| key: const PageStorageKey<String>('ThePositiveNumbers'), |
| itemExtent: 100.0, |
| controller: _controller, |
| itemBuilder: (BuildContext context, int index) { |
| return new Text('${index + from}', key: new ValueKey<int>(index)); |
| } |
| ); |
| } |
| } |
| |
| Future<Null> performTest(WidgetTester tester, bool maintainState) async { |
| final GlobalKey<NavigatorState> navigatorKey = new GlobalKey<NavigatorState>(); |
| await tester.pumpWidget( |
| new Directionality( |
| textDirection: TextDirection.ltr, |
| child: new Navigator( |
| key: navigatorKey, |
| onGenerateRoute: (RouteSettings settings) { |
| if (settings.name == '/') { |
| return new MaterialPageRoute<void>( |
| settings: settings, |
| builder: (_) => new Container(child: const ThePositiveNumbers(from: 0)), |
| maintainState: maintainState, |
| ); |
| } else if (settings.name == '/second') { |
| return new MaterialPageRoute<void>( |
| settings: settings, |
| builder: (_) => new Container(child: const ThePositiveNumbers(from: 10000)), |
| maintainState: maintainState, |
| ); |
| } |
| return null; |
| } |
| ), |
| ), |
| ); |
| |
| // we're 600 pixels high, each item is 100 pixels high, scroll position is |
| // 110.0, so we should have 7 items, 1..7. |
| expect(find.text('0'), findsNothing); |
| expect(find.text('1'), findsOneWidget); |
| expect(find.text('2'), findsOneWidget); |
| expect(find.text('3'), findsOneWidget); |
| expect(find.text('4'), findsOneWidget); |
| expect(find.text('5'), findsOneWidget); |
| expect(find.text('6'), findsOneWidget); |
| expect(find.text('7'), findsOneWidget); |
| expect(find.text('8'), findsNothing); |
| expect(find.text('10'), findsNothing); |
| expect(find.text('100'), findsNothing); |
| |
| tester.state<ScrollableState>(find.byType(Scrollable)).position.jumpTo(1000.0); |
| await tester.pump(const Duration(seconds: 1)); |
| |
| // we're 600 pixels high, each item is 100 pixels high, scroll position is |
| // 1000, so we should have exactly 6 items, 10..15. |
| |
| expect(find.text('0'), findsNothing); |
| expect(find.text('1'), findsNothing); |
| expect(find.text('8'), findsNothing); |
| expect(find.text('9'), findsNothing); |
| expect(find.text('10'), findsOneWidget); |
| expect(find.text('11'), findsOneWidget); |
| expect(find.text('12'), findsOneWidget); |
| expect(find.text('13'), findsOneWidget); |
| expect(find.text('14'), findsOneWidget); |
| expect(find.text('15'), findsOneWidget); |
| expect(find.text('16'), findsNothing); |
| expect(find.text('100'), findsNothing); |
| |
| navigatorKey.currentState.pushNamed('/second'); |
| await tester.pump(); // navigating always takes two frames, one to start... |
| await tester.pump(const Duration(seconds: 1)); // ...and one to end the transition |
| |
| // the second list is now visible, starting at 10001 |
| expect(find.text('0'), findsNothing); |
| expect(find.text('1'), findsNothing); |
| expect(find.text('10'), findsNothing); |
| expect(find.text('11'), findsNothing); |
| expect(find.text('10000'), findsNothing); |
| expect(find.text('10001'), findsOneWidget); |
| expect(find.text('10002'), findsOneWidget); |
| expect(find.text('10003'), findsOneWidget); |
| expect(find.text('10004'), findsOneWidget); |
| expect(find.text('10005'), findsOneWidget); |
| expect(find.text('10006'), findsOneWidget); |
| expect(find.text('10007'), findsOneWidget); |
| expect(find.text('10008'), findsNothing); |
| expect(find.text('10010'), findsNothing); |
| expect(find.text('10100'), findsNothing); |
| |
| navigatorKey.currentState.pop(); |
| await tester.pump(); // again, navigating always takes two frames |
| |
| // Ensure we don't clamp the scroll offset even during the navigation. |
| // https://github.com/flutter/flutter/issues/4883 |
| final ScrollableState state = tester.state(find.byType(Scrollable).first); |
| expect(state.position.pixels, equals(1000.0)); |
| |
| await tester.pump(const Duration(seconds: 1)); |
| |
| // we're 600 pixels high, each item is 100 pixels high, scroll position is |
| // 1000, so we should have exactly 6 items, 10..15. |
| |
| expect(find.text('0'), findsNothing); |
| expect(find.text('1'), findsNothing); |
| expect(find.text('8'), findsNothing); |
| expect(find.text('9'), findsNothing); |
| expect(find.text('10'), findsOneWidget); |
| expect(find.text('11'), findsOneWidget); |
| expect(find.text('12'), findsOneWidget); |
| expect(find.text('13'), findsOneWidget); |
| expect(find.text('14'), findsOneWidget); |
| expect(find.text('15'), findsOneWidget); |
| expect(find.text('16'), findsNothing); |
| expect(find.text('100'), findsNothing); |
| } |
| |
| void main() { |
| testWidgets('whether we remember our scroll position', (WidgetTester tester) async { |
| await performTest(tester, true); |
| await performTest(tester, false); |
| }); |
| } |