| // 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_test/flutter_test.dart'; |
| import 'package:flutter/rendering.dart'; |
| import 'package:flutter/widgets.dart'; |
| |
| const Key blockKey = Key('test'); |
| |
| void main() { |
| testWidgets('Cannot scroll a non-overflowing block', (WidgetTester tester) async { |
| await tester.pumpWidget( |
| Directionality( |
| textDirection: TextDirection.ltr, |
| child: ListView( |
| key: blockKey, |
| children: <Widget>[ |
| Container( |
| height: 200.0, // less than 600, the height of the test area |
| child: const Text('Hello'), |
| ), |
| ], |
| ), |
| ), |
| ); |
| |
| final Offset middleOfContainer = tester.getCenter(find.text('Hello')); |
| final Offset target = tester.getCenter(find.byKey(blockKey)); |
| final TestGesture gesture = await tester.startGesture(target); |
| await gesture.moveBy(const Offset(0.0, -10.0)); |
| |
| await tester.pump(const Duration(milliseconds: 1)); |
| |
| expect(tester.getCenter(find.text('Hello')) == middleOfContainer, isTrue); |
| |
| await gesture.up(); |
| }); |
| |
| testWidgets('Can scroll an overflowing block', (WidgetTester tester) async { |
| await tester.pumpWidget( |
| Directionality( |
| textDirection: TextDirection.ltr, |
| child: ListView( |
| key: blockKey, |
| children: <Widget>[ |
| Container( |
| height: 2000.0, // more than 600, the height of the test area |
| child: const Text('Hello'), |
| ), |
| ], |
| ), |
| ), |
| ); |
| |
| final Offset middleOfContainer = tester.getCenter(find.text('Hello')); |
| expect(middleOfContainer.dx, equals(400.0)); |
| expect(middleOfContainer.dy, equals(1000.0)); |
| |
| final Offset target = tester.getCenter(find.byKey(blockKey)); |
| final TestGesture gesture = await tester.startGesture(target); |
| await gesture.moveBy(const Offset(0.0, -10.0)); |
| |
| await tester.pump(); // redo layout |
| |
| expect(tester.getCenter(find.text('Hello')), isNot(equals(middleOfContainer))); |
| |
| await gesture.up(); |
| }); |
| |
| testWidgets('ListView reverse', (WidgetTester tester) async { |
| int first = 0; |
| int second = 0; |
| |
| Widget buildBlock({ bool reverse = false }) { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: ListView( |
| key: UniqueKey(), |
| reverse: reverse, |
| children: <Widget>[ |
| GestureDetector( |
| onTap: () { first += 1; }, |
| child: Container( |
| height: 350.0, // more than half the height of the test area |
| color: const Color(0xFF00FF00), |
| ), |
| ), |
| GestureDetector( |
| onTap: () { second += 1; }, |
| child: Container( |
| height: 350.0, // more than half the height of the test area |
| color: const Color(0xFF0000FF), |
| ), |
| ), |
| ], |
| ), |
| ); |
| } |
| |
| await tester.pumpWidget(buildBlock(reverse: true)); |
| |
| const Offset target = Offset(200.0, 200.0); |
| await tester.tapAt(target); |
| expect(first, equals(0)); |
| expect(second, equals(1)); |
| |
| await tester.pumpWidget(buildBlock(reverse: false)); |
| |
| await tester.tapAt(target); |
| expect(first, equals(1)); |
| expect(second, equals(1)); |
| }); |
| |
| testWidgets('ListView controller', (WidgetTester tester) async { |
| final ScrollController controller = ScrollController(); |
| |
| Widget buildBlock() { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: ListView( |
| controller: controller, |
| children: const <Widget>[Text('A'), Text('B'), Text('C')], |
| ), |
| ); |
| } |
| await tester.pumpWidget(buildBlock()); |
| expect(controller.offset, equals(0.0)); |
| }); |
| |
| testWidgets('SliverBlockChildListDelegate.estimateMaxScrollOffset hits end', (WidgetTester tester) async { |
| final SliverChildListDelegate delegate = SliverChildListDelegate(<Widget>[ |
| Container(), |
| Container(), |
| Container(), |
| Container(), |
| Container(), |
| ]); |
| |
| await tester.pumpWidget( |
| Directionality( |
| textDirection: TextDirection.ltr, |
| child: CustomScrollView( |
| slivers: <Widget>[ |
| SliverList( |
| delegate: delegate, |
| ), |
| ], |
| ), |
| ), |
| ); |
| |
| final SliverMultiBoxAdaptorElement element = tester.element(find.byType(SliverList, skipOffstage: false)); |
| |
| final double maxScrollOffset = element.estimateMaxScrollOffset( |
| null, |
| firstIndex: 3, |
| lastIndex: 4, |
| leadingScrollOffset: 25.0, |
| trailingScrollOffset: 26.0, |
| ); |
| expect(maxScrollOffset, equals(26.0)); |
| }); |
| |
| testWidgets('Resizing a ListView child restores scroll offset', (WidgetTester tester) async { |
| // Regression test for https://github.com/flutter/flutter/issues/9221 |
| final AnimationController controller = AnimationController( |
| vsync: const TestVSync(), |
| duration: const Duration(milliseconds: 200), |
| ); |
| |
| // The overall height of the frame is (as ever) 600 |
| Widget buildFrame() { |
| return Directionality( |
| textDirection: TextDirection.ltr, |
| child: Column( |
| children: <Widget>[ |
| Flexible( |
| // The overall height of the ListView's contents is 500 |
| child: ListView( |
| children: const <Widget>[ |
| SizedBox( |
| height: 150.0, |
| child: Center( |
| child: Text('top'), |
| ), |
| ), |
| SizedBox( |
| height: 200.0, |
| child: Center( |
| child: Text('middle'), |
| ), |
| ), |
| SizedBox( |
| height: 150.0, |
| child: Center( |
| child: Text('bottom'), |
| ), |
| ), |
| ], |
| ), |
| ), |
| // If this widget's height is > 100 the ListView can scroll. |
| SizeTransition( |
| sizeFactor: controller.view, |
| child: const SizedBox( |
| height: 300.0, |
| child: Text('keyboard'), |
| ), |
| ), |
| ], |
| ), |
| ); |
| } |
| |
| await tester.pumpWidget(buildFrame()); |
| expect(find.text('top'), findsOneWidget); |
| |
| final ScrollPosition position = Scrollable.of(tester.element(find.text('middle'))).position; |
| expect(position.viewportDimension, 600.0); |
| expect(position.pixels, 0.0); |
| |
| // Animate the 'keyboard' height from 0 to 300 |
| controller.forward(); |
| await tester.pumpAndSettle(); |
| expect(position.viewportDimension, 300.0); |
| |
| // Scroll the ListView upwards |
| position.jumpTo(200.0); |
| await tester.pumpAndSettle(); |
| expect(position.pixels, 200.0); |
| expect(find.text('top'), findsNothing); |
| |
| // Animate the 'keyboard' height back to 0. This causes the scroll |
| // offset to return to 0.0 |
| controller.reverse(); |
| await tester.pumpAndSettle(); |
| expect(position.viewportDimension, 600.0); |
| expect(position.pixels, 0.0); |
| expect(find.text('top'), findsOneWidget); |
| }); |
| } |