// 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 'package:flutter_test/flutter_test.dart'; import 'package:flutter/material.dart'; class ThePositiveNumbers extends StatelessWidget { @override Widget build(BuildContext context) { return new ScrollableLazyList( itemExtent: 100.0, itemBuilder: (BuildContext context, int start, int count) { List<Widget> result = new List<Widget>(); for (int index = start; index < start + count; index += 1) result.add(new Text('$index', key: new ValueKey<int>(index))); return result; } ); } } void main() { testWidgets('whether we remember our scroll position', (WidgetTester tester) async { GlobalKey<NavigatorState> navigatorKey = new GlobalKey<NavigatorState>(); await tester.pumpWidget(new Navigator( key: navigatorKey, onGenerateRoute: (RouteSettings settings) { if (settings.name == '/') { return new MaterialPageRoute<Null>( settings: settings, builder: (_) => new Container(child: new ThePositiveNumbers()) ); } else if (settings.name == '/second') { return new MaterialPageRoute<Null>( settings: settings, builder: (_) => new Container(child: new ThePositiveNumbers()) ); } return null; } )); // we're 600 pixels high, each item is 100 pixels high, scroll position is // zero, so we should have exactly 6 items, 0..5. expect(find.text('0'), findsOneWidget); 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'), findsNothing); expect(find.text('10'), findsNothing); expect(find.text('100'), findsNothing); ScrollableState targetState = tester.state(find.byType(Scrollable)); targetState.scrollTo(1000.0); await tester.pump(new 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('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 await tester.pump(new Duration(seconds: 1)); // same as the first list again expect(find.text('0'), findsOneWidget); 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'), findsNothing); expect(find.text('10'), findsNothing); expect(find.text('100'), findsNothing); navigatorKey.currentState.pop(); await tester.pump(); // navigating always takes two frames await tester.pump(new 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('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); }); }