packages/flutter/test/widgets/transform_test.dart - mirrors/flutter - Git at Google

 // 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.

 // This file is run as part of a reduced test set in CI on Mac and Windows
 // machines.
 @Tags(<String>['reduced-test-set'])

 import 'dart:math' as math;
 import 'dart:ui' as ui;

 import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:vector_math/vector_math_64.dart';

 void main() {
   testWidgets('Transform origin', (WidgetTester tester) async {
     bool didReceiveTap = false;
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: Stack(
           children: <Widget>[
             Positioned(
               top: 100.0,
               left: 100.0,
               child: Container(
                 width: 100.0,
                 height: 100.0,
                 color: const Color(0xFF0000FF),
               ),
             ),
             Positioned(
               top: 100.0,
               left: 100.0,
               child: SizedBox(
                 width: 100.0,
                 height: 100.0,
                 child: Transform(
                   transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
                   origin: const Offset(100.0, 50.0),
                   child: GestureDetector(
                     onTap: () {
                       didReceiveTap = true;
                     },
                     child: Container(
                       color: const Color(0xFF00FFFF),
                     ),
                   ),
                 ),
               ),
             ),
           ],
         ),
       ),
     );

     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(110.0, 110.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isTrue);
   });

   testWidgets('Transform alignment', (WidgetTester tester) async {
     bool didReceiveTap = false;
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: Stack(
           children: <Widget>[
             Positioned(
               top: 100.0,
               left: 100.0,
               child: Container(
                 width: 100.0,
                 height: 100.0,
                 color: const Color(0xFF0000FF),
               ),
             ),
             Positioned(
               top: 100.0,
               left: 100.0,
               child: SizedBox(
                 width: 100.0,
                 height: 100.0,
                 child: Transform(
                   transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
                   alignment: Alignment.centerRight,
                   child: GestureDetector(
                     onTap: () {
                       didReceiveTap = true;
                     },
                     child: Container(
                       color: const Color(0xFF00FFFF),
                     ),
                   ),
                 ),
               ),
             ),
           ],
         ),
       ),
     );

     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(110.0, 110.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isTrue);
   });

   testWidgets('Transform AlignmentDirectional alignment', (WidgetTester tester) async {
     bool didReceiveTap = false;

     Widget buildFrame(TextDirection textDirection, AlignmentGeometry alignment) {
       return Directionality(
         textDirection: textDirection,
         child: Stack(
           children: <Widget>[
             Positioned(
               top: 100.0,
               left: 100.0,
               child: Container(
                 width: 100.0,
                 height: 100.0,
                 color: const Color(0xFF0000FF),
               ),
             ),
             Positioned(
               top: 100.0,
               left: 100.0,
               child: SizedBox(
                 width: 100.0,
                 height: 100.0,
                 child: Transform(
                   transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
                   alignment: alignment,
                   child: GestureDetector(
                     onTap: () {
                       didReceiveTap = true;
                     },
                     child: Container(
                       color: const Color(0xFF00FFFF),
                     ),
                   ),
                 ),
               ),
             ),
           ],
         ),
       );
     }

     await tester.pumpWidget(buildFrame(TextDirection.ltr, AlignmentDirectional.centerEnd));
     didReceiveTap = false;
     await tester.tapAt(const Offset(110.0, 110.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isTrue);

     await tester.pumpWidget(buildFrame(TextDirection.rtl, AlignmentDirectional.centerStart));
     didReceiveTap = false;
     await tester.tapAt(const Offset(110.0, 110.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isTrue);

     await tester.pumpWidget(buildFrame(TextDirection.ltr, AlignmentDirectional.centerStart));
     didReceiveTap = false;
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(110.0, 150.0));
     expect(didReceiveTap, isTrue);

     await tester.pumpWidget(buildFrame(TextDirection.rtl, AlignmentDirectional.centerEnd));
     didReceiveTap = false;
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(110.0, 150.0));
     expect(didReceiveTap, isTrue);
   });

   testWidgets('Transform offset + alignment', (WidgetTester tester) async {
     bool didReceiveTap = false;
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: Stack(
           children: <Widget>[
             Positioned(
               top: 100.0,
               left: 100.0,
               child: Container(
                 width: 100.0,
                 height: 100.0,
                 color: const Color(0xFF0000FF),
               ),
             ),
             Positioned(
               top: 100.0,
               left: 100.0,
               child: SizedBox(
                 width: 100.0,
                 height: 100.0,
                 child: Transform(
                   transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
                   origin: const Offset(100.0, 0.0),
                   alignment: Alignment.centerLeft,
                   child: GestureDetector(
                     onTap: () {
                       didReceiveTap = true;
                     },
                     child: Container(
                       color: const Color(0xFF00FFFF),
                     ),
                   ),
                 ),
               ),
             ),
           ],
         ),
       ),
     );

     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(110.0, 110.0));
     expect(didReceiveTap, isFalse);
     await tester.tapAt(const Offset(190.0, 150.0));
     expect(didReceiveTap, isTrue);
   });

   testWidgets('Composited transform offset', (WidgetTester tester) async {
     await tester.pumpWidget(
       Center(
         child: SizedBox(
           width: 400.0,
           height: 300.0,
           child: ClipRect(
             child: Transform(
               transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
               child: Opacity(
                 opacity: 0.9,
                 child: Container(
                   color: const Color(0xFF00FF00),
                 ),
               ),
             ),
           ),
         ),
       ),
     );

     final List<Layer> layers = tester.layers
       ..retainWhere((Layer layer) => layer is TransformLayer);
     expect(layers.length, 2);
     // The first transform is from the render view.
     final TransformLayer layer = layers[1] as TransformLayer;
     final Matrix4 transform = layer.transform!;
     expect(transform.getTranslation(), equals(Vector3(100.0, 75.0, 0.0)));
   });

   testWidgets('Transform.rotate', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 2.0,
         child: Opacity(opacity: 0.5, child: Container()),
       ),
     );

     final List<Layer> layers = tester.layers
       ..retainWhere((Layer layer) => layer is TransformLayer);
     expect(layers.length, 2);
     // The first transform is from the render view.
     final TransformLayer layer = layers[1] as TransformLayer;
     final Matrix4 transform = layer.transform!;
     expect(transform.storage, <dynamic>[
       moreOrLessEquals(0.0), 1.0, 0.0, 0.0,
       -1.0, moreOrLessEquals(0.0), 0.0, 0.0,
       0.0, 0.0, 1.0, 0.0,
       700.0, -100.0, 0.0, 1.0,
     ]);
   });

   testWidgets('applyPaintTransform of Transform in Padding', (WidgetTester tester) async {
     await tester.pumpWidget(
       Padding(
         padding: const EdgeInsets.only(
           left: 30.0,
           top: 20.0,
           right: 50.0,
           bottom: 70.0,
         ),
         child: Transform(
           transform: Matrix4.diagonal3Values(2.0, 2.0, 2.0),
           child: const Placeholder(),
         ),
       ),
     );
     expect(tester.getTopLeft(find.byType(Placeholder)), const Offset(30.0, 20.0));
   });

   testWidgets('Transform.translate', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.translate(
         offset: const Offset(100.0, 50.0),
         child: Opacity(opacity: 0.5, child: Container()),
       ),
     );

     // This should not cause a transform layer to be inserted.
     final List<Layer> layers = tester.layers
       ..retainWhere((Layer layer) => layer is TransformLayer);
     expect(layers.length, 1); // only the render view
     expect(tester.getTopLeft(find.byType(Container)), const Offset(100.0, 50.0));
   });

   testWidgets('Transform.scale', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.scale(
         scale: 2.0,
         child: Opacity(opacity: 0.5, child: Container()),
       ),
     );

     final List<Layer> layers = tester.layers
       ..retainWhere((Layer layer) => layer is TransformLayer);
     expect(layers.length, 2);
     // The first transform is from the render view.
     final TransformLayer layer = layers[1] as TransformLayer;
     final Matrix4 transform = layer.transform!;
     expect(transform.storage, <dynamic>[
       // These are column-major, not row-major.
       2.0, 0.0, 0.0, 0.0,
       0.0, 2.0, 0.0, 0.0,
       0.0, 0.0, 1.0, 0.0,
       -400.0, -300.0, 0.0, 1.0, // it's 1600x1200, centered in an 800x600 square
     ]);
   });

   testWidgets('Translated child into translated box - hit test', (WidgetTester tester) async {
     final GlobalKey key1 = GlobalKey();
     bool _pointerDown = false;
     await tester.pumpWidget(
       Transform.translate(
         offset: const Offset(100.0, 50.0),
         child: Transform.translate(
           offset: const Offset(1000.0, 1000.0),
           child: Listener(
             onPointerDown: (PointerDownEvent event) {
               _pointerDown = true;
             },
             child: Container(
               key: key1,
               color: const Color(0xFF000000),
             ),
           ),
         ),
       ),
     );
     expect(_pointerDown, isFalse);
     await tester.tap(find.byKey(key1));
     expect(_pointerDown, isTrue);
   });

   Widget _generateTransform(bool needsCompositing, double angle) {
     final Widget customPaint = CustomPaint(painter: TestRectPainter());
     return Transform(
       transform: MatrixUtils.createCylindricalProjectionTransform(
         radius: 100,
         angle: angle,
         perspective: 0.003,
       ),
       // A RepaintBoundary child forces the Transform to needsCompositing
       child: needsCompositing ? RepaintBoundary(child: customPaint) : customPaint,
     );
   }

   testWidgets(
     '3D transform renders the same with or without needsCompositing',
     (WidgetTester tester) async {
       for (double angle = 0; angle <= math.pi/4; angle += 0.01) {
         await tester.pumpWidget(RepaintBoundary(child: _generateTransform(true, angle)));
         final RenderBox renderBox = tester.binding.renderView.child!;
         final OffsetLayer layer = renderBox.debugLayer! as OffsetLayer;
         final ui.Image imageWithCompositing = await layer.toImage(renderBox.paintBounds);

         await tester.pumpWidget(RepaintBoundary(child: _generateTransform(false, angle)));
         await expectLater(find.byType(RepaintBoundary).first, matchesReferenceImage(imageWithCompositing));
       }
     },
     skip: isBrowser, // due to https://github.com/flutter/flutter/issues/49857
   );

   testWidgets('Transform.translate with FilterQuality produces filter layer', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.translate(
         offset: const Offset(25.0, 25.0),
         filterQuality: FilterQuality.low,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
   });

   testWidgets('Transform.scale with FilterQuality produces filter layer', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.scale(
         scale: 3.14159,
         filterQuality: FilterQuality.low,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
   });

   testWidgets('Transform.rotate with FilterQuality produces filter layer', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 4,
         filterQuality: FilterQuality.low,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
   });

   testWidgets('Transform layers update to match child and filterQuality', (WidgetTester tester) async {
     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 4,
         filterQuality: FilterQuality.low,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>(), hasLength(1));

     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 4,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>(), isEmpty);

     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 4,
         filterQuality: FilterQuality.low,
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>(), isEmpty);

     await tester.pumpWidget(
       Transform.rotate(
         angle: math.pi / 4,
         filterQuality: FilterQuality.low,
         child: const SizedBox(width: 100, height: 100),
       ),
     );
     expect(tester.layers.whereType<ImageFilterLayer>(), hasLength(1));
   });

   testWidgets('Transform layers with filterQuality golden', (WidgetTester tester) async {
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
         child: GridView.count(
           crossAxisCount: 3,
           children: <Widget>[
             Transform.rotate(
               angle: math.pi / 6,
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
             ),
             Transform.scale(
               scale: 1.5,
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
             ),
             Transform.translate(
               offset: const Offset(20.0, 60.0),
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
             ),
             Transform.rotate(
               angle: math.pi / 6,
               filterQuality: FilterQuality.low,
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
             ),
             Transform.scale(
               scale: 1.5,
               filterQuality: FilterQuality.low,
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
             ),
             Transform.translate(
               offset: const Offset(20.0, 60.0),
               filterQuality: FilterQuality.low,
               child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
             ),
           ],
         ),
       ),
     );
     await expectLater(
       find.byType(GridView),
       matchesGoldenFile('transform_golden.BitmapRotate.png'),
     );
   });
 }

 class TestRectPainter extends CustomPainter {
   @override
   void paint(ui.Canvas canvas, ui.Size size) {
     canvas.drawRect(
       const Offset(200, 200) & const Size(10, 10),
       Paint()..color = const Color(0xFFFF0000),
     );
   }
   @override
   bool shouldRepaint(CustomPainter oldDelegate) => true;
 }
	// 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.

	// This file is run as part of a reduced test set in CI on Mac and Windows
	// machines.
	@Tags(<String>['reduced-test-set'])

	import 'dart:math' as math;
	import 'dart:ui' as ui;

	import 'package:flutter/rendering.dart';
	import 'package:flutter/widgets.dart';
	import 'package:flutter_test/flutter_test.dart';
	import 'package:vector_math/vector_math_64.dart';

	void main() {
	testWidgets('Transform origin', (WidgetTester tester) async {
	bool didReceiveTap = false;
	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Stack(
	children: <Widget>[
	Positioned(
	top: 100.0,
	left: 100.0,
	child: Container(
	width: 100.0,
	height: 100.0,
	color: const Color(0xFF0000FF),
	),
	),
	Positioned(
	top: 100.0,
	left: 100.0,
	child: SizedBox(
	width: 100.0,
	height: 100.0,
	child: Transform(
	transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
	origin: const Offset(100.0, 50.0),
	child: GestureDetector(
	onTap: () {
	didReceiveTap = true;
	},
	child: Container(
	color: const Color(0xFF00FFFF),
	),
	),
	),
	),
	),
	],
	),
	),
	);

	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(110.0, 110.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isTrue);
	});

	testWidgets('Transform alignment', (WidgetTester tester) async {
	bool didReceiveTap = false;
	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Stack(
	children: <Widget>[
	Positioned(
	top: 100.0,
	left: 100.0,
	child: Container(
	width: 100.0,
	height: 100.0,
	color: const Color(0xFF0000FF),
	),
	),
	Positioned(
	top: 100.0,
	left: 100.0,
	child: SizedBox(
	width: 100.0,
	height: 100.0,
	child: Transform(
	transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
	alignment: Alignment.centerRight,
	child: GestureDetector(
	onTap: () {
	didReceiveTap = true;
	},
	child: Container(
	color: const Color(0xFF00FFFF),
	),
	),
	),
	),
	),
	],
	),
	),
	);

	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(110.0, 110.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isTrue);
	});

	testWidgets('Transform AlignmentDirectional alignment', (WidgetTester tester) async {
	bool didReceiveTap = false;

	Widget buildFrame(TextDirection textDirection, AlignmentGeometry alignment) {
	return Directionality(
	textDirection: textDirection,
	child: Stack(
	children: <Widget>[
	Positioned(
	top: 100.0,
	left: 100.0,
	child: Container(
	width: 100.0,
	height: 100.0,
	color: const Color(0xFF0000FF),
	),
	),
	Positioned(
	top: 100.0,
	left: 100.0,
	child: SizedBox(
	width: 100.0,
	height: 100.0,
	child: Transform(
	transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
	alignment: alignment,
	child: GestureDetector(
	onTap: () {
	didReceiveTap = true;
	},
	child: Container(
	color: const Color(0xFF00FFFF),
	),
	),
	),
	),
	),
	],
	),
	);
	}

	await tester.pumpWidget(buildFrame(TextDirection.ltr, AlignmentDirectional.centerEnd));
	didReceiveTap = false;
	await tester.tapAt(const Offset(110.0, 110.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isTrue);

	await tester.pumpWidget(buildFrame(TextDirection.rtl, AlignmentDirectional.centerStart));
	didReceiveTap = false;
	await tester.tapAt(const Offset(110.0, 110.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isTrue);

	await tester.pumpWidget(buildFrame(TextDirection.ltr, AlignmentDirectional.centerStart));
	didReceiveTap = false;
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(110.0, 150.0));
	expect(didReceiveTap, isTrue);

	await tester.pumpWidget(buildFrame(TextDirection.rtl, AlignmentDirectional.centerEnd));
	didReceiveTap = false;
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(110.0, 150.0));
	expect(didReceiveTap, isTrue);
	});

	testWidgets('Transform offset + alignment', (WidgetTester tester) async {
	bool didReceiveTap = false;
	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: Stack(
	children: <Widget>[
	Positioned(
	top: 100.0,
	left: 100.0,
	child: Container(
	width: 100.0,
	height: 100.0,
	color: const Color(0xFF0000FF),
	),
	),
	Positioned(
	top: 100.0,
	left: 100.0,
	child: SizedBox(
	width: 100.0,
	height: 100.0,
	child: Transform(
	transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
	origin: const Offset(100.0, 0.0),
	alignment: Alignment.centerLeft,
	child: GestureDetector(
	onTap: () {
	didReceiveTap = true;
	},
	child: Container(
	color: const Color(0xFF00FFFF),
	),
	),
	),
	),
	),
	],
	),
	),
	);

	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(110.0, 110.0));
	expect(didReceiveTap, isFalse);
	await tester.tapAt(const Offset(190.0, 150.0));
	expect(didReceiveTap, isTrue);
	});

	testWidgets('Composited transform offset', (WidgetTester tester) async {
	await tester.pumpWidget(
	Center(
	child: SizedBox(
	width: 400.0,
	height: 300.0,
	child: ClipRect(
	child: Transform(
	transform: Matrix4.diagonal3Values(0.5, 0.5, 1.0),
	child: Opacity(
	opacity: 0.9,
	child: Container(
	color: const Color(0xFF00FF00),
	),
	),
	),
	),
	),
	),
	);

	final List<Layer> layers = tester.layers
	..retainWhere((Layer layer) => layer is TransformLayer);
	expect(layers.length, 2);
	// The first transform is from the render view.
	final TransformLayer layer = layers[1] as TransformLayer;
	final Matrix4 transform = layer.transform!;
	expect(transform.getTranslation(), equals(Vector3(100.0, 75.0, 0.0)));
	});

	testWidgets('Transform.rotate', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 2.0,
	child: Opacity(opacity: 0.5, child: Container()),
	),
	);

	final List<Layer> layers = tester.layers
	..retainWhere((Layer layer) => layer is TransformLayer);
	expect(layers.length, 2);
	// The first transform is from the render view.
	final TransformLayer layer = layers[1] as TransformLayer;
	final Matrix4 transform = layer.transform!;
	expect(transform.storage, <dynamic>[
	moreOrLessEquals(0.0), 1.0, 0.0, 0.0,
	-1.0, moreOrLessEquals(0.0), 0.0, 0.0,
	0.0, 0.0, 1.0, 0.0,
	700.0, -100.0, 0.0, 1.0,
	]);
	});

	testWidgets('applyPaintTransform of Transform in Padding', (WidgetTester tester) async {
	await tester.pumpWidget(
	Padding(
	padding: const EdgeInsets.only(
	left: 30.0,
	top: 20.0,
	right: 50.0,
	bottom: 70.0,
	),
	child: Transform(
	transform: Matrix4.diagonal3Values(2.0, 2.0, 2.0),
	child: const Placeholder(),
	),
	),
	);
	expect(tester.getTopLeft(find.byType(Placeholder)), const Offset(30.0, 20.0));
	});

	testWidgets('Transform.translate', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.translate(
	offset: const Offset(100.0, 50.0),
	child: Opacity(opacity: 0.5, child: Container()),
	),
	);

	// This should not cause a transform layer to be inserted.
	final List<Layer> layers = tester.layers
	..retainWhere((Layer layer) => layer is TransformLayer);
	expect(layers.length, 1); // only the render view
	expect(tester.getTopLeft(find.byType(Container)), const Offset(100.0, 50.0));
	});

	testWidgets('Transform.scale', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.scale(
	scale: 2.0,
	child: Opacity(opacity: 0.5, child: Container()),
	),
	);

	final List<Layer> layers = tester.layers
	..retainWhere((Layer layer) => layer is TransformLayer);
	expect(layers.length, 2);
	// The first transform is from the render view.
	final TransformLayer layer = layers[1] as TransformLayer;
	final Matrix4 transform = layer.transform!;
	expect(transform.storage, <dynamic>[
	// These are column-major, not row-major.
	2.0, 0.0, 0.0, 0.0,
	0.0, 2.0, 0.0, 0.0,
	0.0, 0.0, 1.0, 0.0,
	-400.0, -300.0, 0.0, 1.0, // it's 1600x1200, centered in an 800x600 square
	]);
	});

	testWidgets('Translated child into translated box - hit test', (WidgetTester tester) async {
	final GlobalKey key1 = GlobalKey();
	bool _pointerDown = false;
	await tester.pumpWidget(
	Transform.translate(
	offset: const Offset(100.0, 50.0),
	child: Transform.translate(
	offset: const Offset(1000.0, 1000.0),
	child: Listener(
	onPointerDown: (PointerDownEvent event) {
	_pointerDown = true;
	},
	child: Container(
	key: key1,
	color: const Color(0xFF000000),
	),
	),
	),
	),
	);
	expect(_pointerDown, isFalse);
	await tester.tap(find.byKey(key1));
	expect(_pointerDown, isTrue);
	});

	Widget _generateTransform(bool needsCompositing, double angle) {
	final Widget customPaint = CustomPaint(painter: TestRectPainter());
	return Transform(
	transform: MatrixUtils.createCylindricalProjectionTransform(
	radius: 100,
	angle: angle,
	perspective: 0.003,
	),
	// A RepaintBoundary child forces the Transform to needsCompositing
	child: needsCompositing ? RepaintBoundary(child: customPaint) : customPaint,
	);
	}

	testWidgets(
	'3D transform renders the same with or without needsCompositing',
	(WidgetTester tester) async {
	for (double angle = 0; angle <= math.pi/4; angle += 0.01) {
	await tester.pumpWidget(RepaintBoundary(child: _generateTransform(true, angle)));
	final RenderBox renderBox = tester.binding.renderView.child!;
	final OffsetLayer layer = renderBox.debugLayer! as OffsetLayer;
	final ui.Image imageWithCompositing = await layer.toImage(renderBox.paintBounds);

	await tester.pumpWidget(RepaintBoundary(child: _generateTransform(false, angle)));
	await expectLater(find.byType(RepaintBoundary).first, matchesReferenceImage(imageWithCompositing));
	}
	},
	skip: isBrowser, // due to https://github.com/flutter/flutter/issues/49857
	);

	testWidgets('Transform.translate with FilterQuality produces filter layer', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.translate(
	offset: const Offset(25.0, 25.0),
	filterQuality: FilterQuality.low,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
	});

	testWidgets('Transform.scale with FilterQuality produces filter layer', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.scale(
	scale: 3.14159,
	filterQuality: FilterQuality.low,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
	});

	testWidgets('Transform.rotate with FilterQuality produces filter layer', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 4,
	filterQuality: FilterQuality.low,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>().length, 1);
	});

	testWidgets('Transform layers update to match child and filterQuality', (WidgetTester tester) async {
	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 4,
	filterQuality: FilterQuality.low,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>(), hasLength(1));

	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 4,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>(), isEmpty);

	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 4,
	filterQuality: FilterQuality.low,
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>(), isEmpty);

	await tester.pumpWidget(
	Transform.rotate(
	angle: math.pi / 4,
	filterQuality: FilterQuality.low,
	child: const SizedBox(width: 100, height: 100),
	),
	);
	expect(tester.layers.whereType<ImageFilterLayer>(), hasLength(1));
	});

	testWidgets('Transform layers with filterQuality golden', (WidgetTester tester) async {
	await tester.pumpWidget(
	Directionality(
	textDirection: TextDirection.ltr,
	child: GridView.count(
	crossAxisCount: 3,
	children: <Widget>[
	Transform.rotate(
	angle: math.pi / 6,
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
	),
	Transform.scale(
	scale: 1.5,
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
	),
	Transform.translate(
	offset: const Offset(20.0, 60.0),
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xffffff00))),
	),
	Transform.rotate(
	angle: math.pi / 6,
	filterQuality: FilterQuality.low,
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
	),
	Transform.scale(
	scale: 1.5,
	filterQuality: FilterQuality.low,
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
	),
	Transform.translate(
	offset: const Offset(20.0, 60.0),
	filterQuality: FilterQuality.low,
	child: Center(child: Container(width: 100, height: 20, color: const Color(0xff00ff00))),
	),
	],
	),
	),
	);
	await expectLater(
	find.byType(GridView),
	matchesGoldenFile('transform_golden.BitmapRotate.png'),
	);
	});
	}

	class TestRectPainter extends CustomPainter {
	@override
	void paint(ui.Canvas canvas, ui.Size size) {
	canvas.drawRect(
	const Offset(200, 200) & const Size(10, 10),
	Paint()..color = const Color(0xFFFF0000),
	);
	}
	@override
	bool shouldRepaint(CustomPainter oldDelegate) => true;
	}