// 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/rendering.dart'; import 'package:flutter/widgets.dart'; class TestMultiChildLayoutDelegate extends MultiChildLayoutDelegate { BoxConstraints getSizeConstraints; @override Size getSize(BoxConstraints constraints) { if (!RenderObject.debugCheckingIntrinsics) getSizeConstraints = constraints; return const Size(200.0, 300.0); } Size performLayoutSize; Size performLayoutSize0; Size performLayoutSize1; bool performLayoutIsChild; @override void performLayout(Size size) { assert(!RenderObject.debugCheckingIntrinsics); expect(() { performLayoutSize = size; final BoxConstraints constraints = BoxConstraints.loose(size); performLayoutSize0 = layoutChild(0, constraints); performLayoutSize1 = layoutChild(1, constraints); performLayoutIsChild = hasChild('fred'); }, returnsNormally); } bool shouldRelayoutCalled = false; bool shouldRelayoutValue = false; @override bool shouldRelayout(_) { assert(!RenderObject.debugCheckingIntrinsics); shouldRelayoutCalled = true; return shouldRelayoutValue; } } Widget buildFrame(MultiChildLayoutDelegate delegate) { return Center( child: CustomMultiChildLayout( children: <Widget>[ LayoutId(id: 0, child: Container(width: 150.0, height: 100.0)), LayoutId(id: 1, child: Container(width: 100.0, height: 200.0)), ], delegate: delegate, ), ); } class PreferredSizeDelegate extends MultiChildLayoutDelegate { PreferredSizeDelegate({ this.preferredSize }); final Size preferredSize; @override Size getSize(BoxConstraints constraints) => preferredSize; @override void performLayout(Size size) { } @override bool shouldRelayout(PreferredSizeDelegate oldDelegate) { return preferredSize != oldDelegate.preferredSize; } } void main() { testWidgets('Control test for CustomMultiChildLayout', (WidgetTester tester) async { final TestMultiChildLayoutDelegate delegate = TestMultiChildLayoutDelegate(); await tester.pumpWidget(buildFrame(delegate)); expect(delegate.getSizeConstraints.minWidth, 0.0); expect(delegate.getSizeConstraints.maxWidth, 800.0); expect(delegate.getSizeConstraints.minHeight, 0.0); expect(delegate.getSizeConstraints.maxHeight, 600.0); expect(delegate.performLayoutSize.width, 200.0); expect(delegate.performLayoutSize.height, 300.0); expect(delegate.performLayoutSize0.width, 150.0); expect(delegate.performLayoutSize0.height, 100.0); expect(delegate.performLayoutSize1.width, 100.0); expect(delegate.performLayoutSize1.height, 200.0); expect(delegate.performLayoutIsChild, false); }); testWidgets('Test MultiChildDelegate shouldRelayout method', (WidgetTester tester) async { TestMultiChildLayoutDelegate delegate = TestMultiChildLayoutDelegate(); await tester.pumpWidget(buildFrame(delegate)); // Layout happened because the delegate was set. expect(delegate.performLayoutSize, isNotNull); // i.e. layout happened expect(delegate.shouldRelayoutCalled, isFalse); // Layout did not happen because shouldRelayout() returned false. delegate = TestMultiChildLayoutDelegate(); delegate.shouldRelayoutValue = false; await tester.pumpWidget(buildFrame(delegate)); expect(delegate.shouldRelayoutCalled, isTrue); expect(delegate.performLayoutSize, isNull); // Layout happened because shouldRelayout() returned true. delegate = TestMultiChildLayoutDelegate(); delegate.shouldRelayoutValue = true; await tester.pumpWidget(buildFrame(delegate)); expect(delegate.shouldRelayoutCalled, isTrue); expect(delegate.performLayoutSize, isNotNull); }); testWidgets('Nested CustomMultiChildLayouts', (WidgetTester tester) async { final TestMultiChildLayoutDelegate delegate = TestMultiChildLayoutDelegate(); await tester.pumpWidget(Center( child: CustomMultiChildLayout( children: <Widget>[ LayoutId( id: 0, child: CustomMultiChildLayout( children: <Widget>[ LayoutId(id: 0, child: Container(width: 150.0, height: 100.0)), LayoutId(id: 1, child: Container(width: 100.0, height: 200.0)), ], delegate: delegate, ), ), LayoutId(id: 1, child: Container(width: 100.0, height: 200.0)), ], delegate: delegate, ), )); }); testWidgets('Loose constraints', (WidgetTester tester) async { final Key key = UniqueKey(); await tester.pumpWidget(Center( child: CustomMultiChildLayout( key: key, delegate: PreferredSizeDelegate(preferredSize: const Size(300.0, 200.0)), ), )); final RenderBox box = tester.renderObject(find.byKey(key)); expect(box.size.width, equals(300.0)); expect(box.size.height, equals(200.0)); await tester.pumpWidget(Center( child: CustomMultiChildLayout( key: key, delegate: PreferredSizeDelegate(preferredSize: const Size(350.0, 250.0)), ), )); expect(box.size.width, equals(350.0)); expect(box.size.height, equals(250.0)); }); }