// 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/rendering.dart'; import 'package:flutter/widgets.dart'; import 'package:flutter_test/flutter_test.dart'; import '../rendering/recording_canvas.dart'; final BoxDecoration kBoxDecorationA = BoxDecoration(border: nonconst(null)); final BoxDecoration kBoxDecorationB = BoxDecoration(border: nonconst(null)); final BoxDecoration kBoxDecorationC = BoxDecoration(border: nonconst(null)); class TestWidget extends StatelessWidget { const TestWidget({ super.key, required this.child, }); final Widget child; @override Widget build(BuildContext context) => child; } class TestOrientedBox extends SingleChildRenderObjectWidget { const TestOrientedBox({ super.key, super.child }); Decoration _getDecoration(BuildContext context) { final Orientation orientation = MediaQuery.of(context).orientation; switch (orientation) { case Orientation.landscape: return const BoxDecoration(color: Color(0xFF00FF00)); case Orientation.portrait: return const BoxDecoration(color: Color(0xFF0000FF)); } } @override RenderDecoratedBox createRenderObject(BuildContext context) => RenderDecoratedBox(decoration: _getDecoration(context)); @override void updateRenderObject(BuildContext context, RenderDecoratedBox renderObject) { renderObject.decoration = _getDecoration(context); } } class TestNonVisitingWidget extends SingleChildRenderObjectWidget { const TestNonVisitingWidget({ super.key, required Widget super.child }); @override RenderObject createRenderObject(BuildContext context) => TestNonVisitingRenderObject(); } class TestNonVisitingRenderObject extends RenderBox with RenderObjectWithChildMixin<RenderBox> { @override Size computeDryLayout(BoxConstraints constraints) { return child!.getDryLayout(constraints); } @override void performLayout() { child!.layout(constraints, parentUsesSize: true); size = child!.size; } @override void paint(PaintingContext context, Offset offset) { context.paintChild(child!, offset); } @override void visitChildren(RenderObjectVisitor visitor) { // oops! } } void main() { testWidgets('RenderObjectWidget smoke test', (WidgetTester tester) async { await tester.pumpWidget(DecoratedBox(decoration: kBoxDecorationA)); SingleChildRenderObjectElement element = tester.element(find.byElementType(SingleChildRenderObjectElement)); expect(element, isNotNull); expect(element.renderObject, isA<RenderDecoratedBox>()); RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox; expect(renderObject.decoration, equals(kBoxDecorationA)); expect(renderObject.position, equals(DecorationPosition.background)); await tester.pumpWidget(DecoratedBox(decoration: kBoxDecorationB)); element = tester.element(find.byElementType(SingleChildRenderObjectElement)); expect(element, isNotNull); expect(element.renderObject, isA<RenderDecoratedBox>()); renderObject = element.renderObject as RenderDecoratedBox; expect(renderObject.decoration, equals(kBoxDecorationB)); expect(renderObject.position, equals(DecorationPosition.background)); }); testWidgets('RenderObjectWidget can add and remove children', (WidgetTester tester) async { void checkFullTree() { final SingleChildRenderObjectElement element = tester.firstElement(find.byElementType(SingleChildRenderObjectElement)); expect(element, isNotNull); expect(element.renderObject, isA<RenderDecoratedBox>()); final RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox; expect(renderObject.decoration, equals(kBoxDecorationA)); expect(renderObject.position, equals(DecorationPosition.background)); expect(renderObject.child, isNotNull); expect(renderObject.child, isA<RenderDecoratedBox>()); final RenderDecoratedBox child = renderObject.child! as RenderDecoratedBox; expect(child.decoration, equals(kBoxDecorationB)); expect(child.position, equals(DecorationPosition.background)); expect(child.child, isNull); } void childBareTree() { final SingleChildRenderObjectElement element = tester.element(find.byElementType(SingleChildRenderObjectElement)); expect(element, isNotNull); expect(element.renderObject, isA<RenderDecoratedBox>()); final RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox; expect(renderObject.decoration, equals(kBoxDecorationA)); expect(renderObject.position, equals(DecorationPosition.background)); expect(renderObject.child, isNull); } await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, child: DecoratedBox( decoration: kBoxDecorationB, ), )); checkFullTree(); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, child: TestWidget( child: DecoratedBox( decoration: kBoxDecorationB, ), ), )); checkFullTree(); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, child: DecoratedBox( decoration: kBoxDecorationB, ), )); checkFullTree(); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, )); childBareTree(); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, child: TestWidget( child: TestWidget( child: DecoratedBox( decoration: kBoxDecorationB, ), ), ), )); checkFullTree(); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, )); childBareTree(); }); testWidgets('Detached render tree is intact', (WidgetTester tester) async { await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, child: DecoratedBox( decoration: kBoxDecorationB, child: DecoratedBox( decoration: kBoxDecorationC, ), ), )); SingleChildRenderObjectElement element = tester.firstElement(find.byElementType(SingleChildRenderObjectElement)); expect(element.renderObject, isA<RenderDecoratedBox>()); final RenderDecoratedBox parent = element.renderObject as RenderDecoratedBox; expect(parent.child, isA<RenderDecoratedBox>()); final RenderDecoratedBox child = parent.child! as RenderDecoratedBox; expect(child.decoration, equals(kBoxDecorationB)); expect(child.child, isA<RenderDecoratedBox>()); final RenderDecoratedBox grandChild = child.child! as RenderDecoratedBox; expect(grandChild.decoration, equals(kBoxDecorationC)); expect(grandChild.child, isNull); await tester.pumpWidget(DecoratedBox( decoration: kBoxDecorationA, )); element = tester.element(find.byElementType(SingleChildRenderObjectElement)); expect(element.renderObject, isA<RenderDecoratedBox>()); expect(element.renderObject, equals(parent)); expect(parent.child, isNull); expect(child.parent, isNull); expect(child.decoration, equals(kBoxDecorationB)); expect(child.child, equals(grandChild)); expect(grandChild.parent, equals(child)); expect(grandChild.decoration, equals(kBoxDecorationC)); expect(grandChild.child, isNull); }); testWidgets('Can watch inherited widgets', (WidgetTester tester) async { final Key boxKey = UniqueKey(); final TestOrientedBox box = TestOrientedBox(key: boxKey); await tester.pumpWidget(MediaQuery( data: const MediaQueryData(size: Size(400.0, 300.0)), child: box, )); final RenderDecoratedBox renderBox = tester.renderObject(find.byKey(boxKey)); BoxDecoration decoration = renderBox.decoration as BoxDecoration; expect(decoration.color, equals(const Color(0xFF00FF00))); await tester.pumpWidget(MediaQuery( data: const MediaQueryData(size: Size(300.0, 400.0)), child: box, )); decoration = renderBox.decoration as BoxDecoration; expect(decoration.color, equals(const Color(0xFF0000FF))); }); testWidgets('RenderObject not visiting children provides helpful error message', (WidgetTester tester) async { await tester.pumpWidget( TestNonVisitingWidget( child: Container(color: const Color(0xFFED1D7F)), ), ); final RenderObject renderObject = tester.renderObject(find.byType(TestNonVisitingWidget)); final Canvas testCanvas = TestRecordingCanvas(); final PaintingContext testContext = TestRecordingPaintingContext(testCanvas); // When a parent fails to visit a child in visitChildren, the child's compositing // bits won't be cleared properly, leading to an exception during paint. renderObject.paint(testContext, Offset.zero); final dynamic error = tester.takeException(); expect(error, isNotNull, reason: 'RenderObject did not throw when painting'); expect(error, isFlutterError); expect(error.toString(), contains("A RenderObject was not visited by the parent's visitChildren")); }); }