testing/scenario_app/lib/src/platform_view.dart - external/github.com/flutter/engine - Git at Google

 // Copyright 2013 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.

 // @dart = 2.6
 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 import 'dart:ui';
 import 'package:vector_math/vector_math_64.dart';

 import 'scenario.dart';

 List<int> _to32(int value) {
   final Uint8List temp = Uint8List(4);
   temp.buffer.asByteData().setInt32(0, value, Endian.little);
   return temp;
 }

 List<int> _to64(num value) {
   final Uint8List temp = Uint8List(15);
   if (value is double) {
     temp.buffer.asByteData().setFloat64(7, value, Endian.little);
   } else if (value is int) {
     temp.buffer.asByteData().setInt64(7, value, Endian.little);
   }
   return temp;
 }

 /// A simple platform view.
 class PlatformViewScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     finishBuilderByAddingPlatformViewAndPicture(builder, 0);
   }
 }

 /// A simple platform view with overlay that doesn't intersect with the platform view.
 class PlatformViewNoOverlayIntersectionScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewNoOverlayIntersectionScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     finishBuilderByAddingPlatformViewAndPicture(
       builder,
       0,
       overlayOffset: const Offset(150, 350),
     );
   }
 }

 /// A simple platform view with an overlay that partially intersects with the platform view.
 class PlatformViewPartialIntersectionScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewPartialIntersectionScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     finishBuilderByAddingPlatformViewAndPicture(
       builder,
       0,
       overlayOffset: const Offset(150, 250),
     );
   }
 }

 /// A simple platform view with two overlays that intersect with each other and the platform view.
 class PlatformViewTwoIntersectingOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewTwoIntersectingOverlaysScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     _addPlatformViewtoScene(builder, 0, 500, 500);
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawCircle(
       const Offset(50, 50),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(100, 100),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     final Picture picture = recorder.endRecording();
     builder.addPicture(const Offset(300, 300), picture);
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }
 }

 /// A simple platform view with one overlay and two overlays that intersect with each other and the platform view.
 class PlatformViewOneOverlayTwoIntersectingOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewOneOverlayTwoIntersectingOverlaysScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     _addPlatformViewtoScene(builder, 0, 500, 500);
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawCircle(
       const Offset(50, 50),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(100, 100),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(-100, 200),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     final Picture picture = recorder.endRecording();
     builder.addPicture(const Offset(300, 300), picture);
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }
 }

 /// Two platform views without an overlay intersecting either platform view.
 class MultiPlatformViewWithoutOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   MultiPlatformViewWithoutOverlaysScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     builder.pushOffset(0, 600);
     _addPlatformViewtoScene(builder, 0, 500, 500);
     builder.pop();

     _addPlatformViewtoScene(builder, 1, 500, 500);

     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawRect(
       const Rect.fromLTRB(0, 0, 100, 1000),
       Paint()..color = const Color(0xFFFF0000),
     );
     final Picture picture = recorder.endRecording();
     builder.addPicture(const Offset(580, 0), picture);

     builder.pop();
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }
 }

 /// A simple platform view with too many overlays result in a single native view.
 class PlatformViewMaxOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewMaxOverlaysScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     _addPlatformViewtoScene(builder, 0, 500, 500);
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawCircle(
       const Offset(50, 50),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(100, 100),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(-100, 200),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     canvas.drawCircle(
       const Offset(-100, -80),
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     final Picture picture = recorder.endRecording();
     builder.addPicture(const Offset(300, 300), picture);
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }
 }

 /// Builds a scene with 2 platform views.
 class MultiPlatformViewScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   MultiPlatformViewScenario(Window window, {this.firstId, this.secondId})
       : assert(window != null),
         super(window) {
     createPlatformView(window, 'platform view 1', firstId);
     createPlatformView(window, 'platform view 2', secondId);
   }

   /// The platform view identifier to use for the first platform view.
   final int firstId;

   /// The platform view identifier to use for the second platform view.
   final int secondId;

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     builder.pushOffset(0, 600);
     _addPlatformViewtoScene(builder, firstId, 500, 500);
     builder.pop();

     finishBuilderByAddingPlatformViewAndPicture(builder, secondId);
   }
 }

 /// Scenario for verifying platform views after background and foregrounding the app.
 ///
 /// Renders a frame with 2 platform views covered by a flutter drawn rectangle,
 /// when the app goes to the background and comes back to the foreground renders a new frame
 /// with the 2 platform views but without the flutter drawn rectangle.
 class MultiPlatformViewBackgroundForegroundScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   MultiPlatformViewBackgroundForegroundScenario(Window window, {this.firstId, this.secondId})
       : assert(window != null),
         super(window) {
     createPlatformView(window, 'platform view 1', firstId);
     createPlatformView(window, 'platform view 2', secondId);
     _nextFrame = _firstFrame;
   }

   /// The platform view identifier to use for the first platform view.
   final int firstId;

   /// The platform view identifier to use for the second platform view.
   final int secondId;

   @override
   void onBeginFrame(Duration duration) {
     _nextFrame();
   }

   VoidCallback _nextFrame;

   void _firstFrame() {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     builder.pushOffset(0, 600);
     _addPlatformViewtoScene(builder, firstId, 500, 500);
     builder.pop();

     _addPlatformViewtoScene(builder, secondId, 500, 500);

     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawRect(
       const Rect.fromLTRB(0, 0, 500, 1000),
       Paint()..color = const Color(0xFFFF0000),
     );
     final Picture picture = recorder.endRecording();
     builder.addPicture(const Offset(0, 0), picture);

     builder.pop();
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }

   void _secondFrame() {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     builder.pushOffset(0, 600);
     _addPlatformViewtoScene(builder, firstId, 500, 500);
     builder.pop();

     _addPlatformViewtoScene(builder, secondId, 500, 500);
     final Scene scene = builder.build();
     window.render(scene);
     scene.dispose();
   }

   String _lastLifecycleState = '';

   @override
   void onPlatformMessage(
       String name,
       ByteData data,
       PlatformMessageResponseCallback callback,
       ) {
     if (name != 'flutter/lifecycle') {
       return;
     }
     final String message = utf8.decode(data.buffer.asUint8List());
     if (_lastLifecycleState == 'AppLifecycleState.inactive' && message == 'AppLifecycleState.resumed') {
       _nextFrame = _secondFrame;
       window.scheduleFrame();
     }

     _lastLifecycleState = message;
   }
 }

 /// Platform view with clip rect.
 class PlatformViewClipRectScenario extends Scenario with _BasePlatformViewScenarioMixin {
   /// Constructs a platform view with clip rect scenario.
   PlatformViewClipRectScenario(Window window, String text, {int id = 0})
       : assert(window != null),
         super(window) {
     createPlatformView(window, text, id);
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();
     builder.pushOffset(0, 0);
     builder.pushClipRect(const Rect.fromLTRB(100, 100, 400, 400));
     finishBuilderByAddingPlatformViewAndPicture(builder, 1);
   }
 }

 /// Platform view with clip rrect.
 class PlatformViewClipRRectScenario extends PlatformViewScenario {
   /// Constructs a platform view with clip rrect scenario.
   PlatformViewClipRRectScenario(Window window, String text, {int id = 0})
       : super(window, text, id: id);

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);
     builder.pushClipRRect(
       RRect.fromLTRBAndCorners(
         100,
         100,
         400,
         400,
         topLeft: const Radius.circular(15),
         topRight: const Radius.circular(50),
         bottomLeft: const Radius.circular(50),
       ),
     );
     finishBuilderByAddingPlatformViewAndPicture(builder, 2);
   }
 }

 /// Platform view with clip path.
 class PlatformViewClipPathScenario extends PlatformViewScenario {
   /// Constructs a platform view with clip rrect scenario.
   PlatformViewClipPathScenario(Window window, String text, {int id = 0})
       : super(window, text, id: id);

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);

     final Path path = Path()
       ..moveTo(100, 100)
       ..quadraticBezierTo(50, 250, 100, 400)
       ..lineTo(350, 400)
       ..cubicTo(400, 300, 300, 200, 350, 100)
       ..close();
     builder.pushClipPath(path);

     finishBuilderByAddingPlatformViewAndPicture(builder, 3);
   }
 }

 /// Platform view with transform.
 class PlatformViewTransformScenario extends PlatformViewScenario {
   /// Constructs a platform view with transform scenario.
   PlatformViewTransformScenario(Window window, String text, {int id = 0})
       : super(window, text, id: id);

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);
     final Matrix4 matrix4 = Matrix4.identity()
       ..rotateZ(1)
       ..scale(0.5, 0.5, 1.0)
       ..translate(1000.0, 100.0, 0.0);

     builder.pushTransform(matrix4.storage);

     finishBuilderByAddingPlatformViewAndPicture(builder, 4);
   }
 }

 /// Platform view with opacity.
 class PlatformViewOpacityScenario extends PlatformViewScenario {
   /// Constructs a platform view with transform scenario.
   PlatformViewOpacityScenario(Window window, String text, {int id = 0})
       : super(window, text, id: id);

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);
     builder.pushOpacity(150);

     finishBuilderByAddingPlatformViewAndPicture(builder, 5);
   }
 }

 /// A simple platform view for testing touch events from iOS.
 class PlatformViewForTouchIOSScenario extends Scenario
     with _BasePlatformViewScenarioMixin {

   int _viewId;
   bool _accept;
   /// Creates the PlatformView scenario.
   ///
   /// The [window] parameter must not be null.
   PlatformViewForTouchIOSScenario(Window window, String text, {int id = 0, bool accept, bool rejectUntilTouchesEnded = false})
       : assert(window != null),
        _accept = accept,
       _viewId = id,
         super(window) {
     if (rejectUntilTouchesEnded) {
       createPlatformView(window, text, id, viewType: 'scenarios/textPlatformView_blockPolicyUntilTouchesEnded');
     } else {
       createPlatformView(window, text, id);
     }
   }

   @override
   void onBeginFrame(Duration duration) {
     final SceneBuilder builder = SceneBuilder();

     builder.pushOffset(0, 0);
     finishBuilderByAddingPlatformViewAndPicture(builder, 11);
   }

   @override
   void onPointerDataPacket(PointerDataPacket packet) {
     if (packet.data.first.change == PointerChange.add) {
     String method = 'rejectGesture';
     if (_accept) {
       method = 'acceptGesture';
     }
     const int _valueString = 7;
     const int _valueInt32 = 3;
     const int _valueMap = 13;
     final Uint8List message = Uint8List.fromList(<int>[
       _valueString,
       method.length,
       ...utf8.encode(method),
       _valueMap,
       1,
       _valueString,
       'id'.length,
       ...utf8.encode('id'),
       _valueInt32,
       ..._to32(_viewId),
     ]);
     window.sendPlatformMessage(
       'flutter/platform_views',
       message.buffer.asByteData(),
       (ByteData response) {},
     );
     }

   }
 }

 mixin _BasePlatformViewScenarioMixin on Scenario {
   int _textureId;

   /// Construct the platform view related scenario
   ///
   /// It prepare a TextPlatformView so it can be added to the SceneBuilder in `onBeginFrame`.
   /// Call this method in the constructor of the platform view related scenarios
   /// to perform necessary set up.
   void createPlatformView(Window window, String text, int id, {String viewType = 'scenarios/textPlatformView'}) {
     const int _valueInt32 = 3;
     const int _valueFloat64 = 6;
     const int _valueString = 7;
     const int _valueUint8List = 8;
     const int _valueMap = 13;
     final Uint8List message = Uint8List.fromList(<int>[
       _valueString,
       'create'.length, // this won't work if we use multi-byte characters.
       ...utf8.encode('create'),
       _valueMap,
       if (Platform.isIOS)
         3, // 3 entries in map for iOS.
       if (Platform.isAndroid)
         6, // 6 entries in map for Android.
       _valueString,
       'id'.length,
       ...utf8.encode('id'),
       _valueInt32,
       ..._to32(id),
       _valueString,
       'viewType'.length,
       ...utf8.encode('viewType'),
       _valueString,
       viewType.length,
       ...utf8.encode(viewType),
       if (Platform.isAndroid) ...<int>[
         _valueString,
         'width'.length,
         ...utf8.encode('width'),
         _valueFloat64,
         ..._to64(500.0),
         _valueString,
         'height'.length,
         ...utf8.encode('height'),
         _valueFloat64,
         ..._to64(500.0),
         _valueString,
         'direction'.length,
         ...utf8.encode('direction'),
         _valueInt32,
         ..._to32(0), // LTR
       ],
       _valueString,
       'params'.length,
       ...utf8.encode('params'),
       _valueUint8List,
       text.length,
       ...utf8.encode(text),
     ]);

     window.sendPlatformMessage(
       'flutter/platform_views',
       message.buffer.asByteData(),
       (ByteData response) {
         if (response != null && Platform.isAndroid) {
           // Envelope.
           _textureId = response.getUint8(0);
         }
       },
     );
   }

   void _addPlatformViewtoScene(
     SceneBuilder sceneBuilder,
     int viewId,
     double width,
     double height, {
     Offset overlayOffset,
   }) {
     overlayOffset ??= const Offset(50, 50);
     if (Platform.isIOS) {
       sceneBuilder.addPlatformView(viewId, offset: overlayOffset, width: width, height: height);
     } else if (Platform.isAndroid && _textureId != null) {
       sceneBuilder.addTexture(_textureId, offset: overlayOffset, width: width, height: height);
     } else {
       throw UnsupportedError('Platform ${Platform.operatingSystem} is not supported');
     }
   }

   // Add a platform view and a picture to the scene, then finish the `sceneBuilder`.
   void finishBuilderByAddingPlatformViewAndPicture(
     SceneBuilder sceneBuilder,
     int viewId, {
     Offset overlayOffset,
   }) {
     overlayOffset ??= const Offset(50, 50);
     _addPlatformViewtoScene(
       sceneBuilder,
       viewId,
       500,
       500,
       overlayOffset: overlayOffset,
     );
     final PictureRecorder recorder = PictureRecorder();
     final Canvas canvas = Canvas(recorder);
     canvas.drawCircle(
       overlayOffset,
       50,
       Paint()..color = const Color(0xFFABCDEF),
     );
     final Picture picture = recorder.endRecording();
     sceneBuilder.addPicture(const Offset(300, 300), picture);
     final Scene scene = sceneBuilder.build();
     window.render(scene);
     scene.dispose();
   }
 }
	// Copyright 2013 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.

	// @dart = 2.6
	import 'dart:convert';
	import 'dart:io';
	import 'dart:typed_data';
	import 'dart:ui';
	import 'package:vector_math/vector_math_64.dart';

	import 'scenario.dart';

	List<int> _to32(int value) {
	final Uint8List temp = Uint8List(4);
	temp.buffer.asByteData().setInt32(0, value, Endian.little);
	return temp;
	}

	List<int> _to64(num value) {
	final Uint8List temp = Uint8List(15);
	if (value is double) {
	temp.buffer.asByteData().setFloat64(7, value, Endian.little);
	} else if (value is int) {
	temp.buffer.asByteData().setInt64(7, value, Endian.little);
	}
	return temp;
	}

	/// A simple platform view.
	class PlatformViewScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	finishBuilderByAddingPlatformViewAndPicture(builder, 0);
	}
	}

	/// A simple platform view with overlay that doesn't intersect with the platform view.
	class PlatformViewNoOverlayIntersectionScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewNoOverlayIntersectionScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	finishBuilderByAddingPlatformViewAndPicture(
	builder,
	0,
	overlayOffset: const Offset(150, 350),
	);
	}
	}

	/// A simple platform view with an overlay that partially intersects with the platform view.
	class PlatformViewPartialIntersectionScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewPartialIntersectionScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	finishBuilderByAddingPlatformViewAndPicture(
	builder,
	0,
	overlayOffset: const Offset(150, 250),
	);
	}
	}

	/// A simple platform view with two overlays that intersect with each other and the platform view.
	class PlatformViewTwoIntersectingOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewTwoIntersectingOverlaysScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	_addPlatformViewtoScene(builder, 0, 500, 500);
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawCircle(
	const Offset(50, 50),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(100, 100),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	final Picture picture = recorder.endRecording();
	builder.addPicture(const Offset(300, 300), picture);
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}
	}

	/// A simple platform view with one overlay and two overlays that intersect with each other and the platform view.
	class PlatformViewOneOverlayTwoIntersectingOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewOneOverlayTwoIntersectingOverlaysScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	_addPlatformViewtoScene(builder, 0, 500, 500);
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawCircle(
	const Offset(50, 50),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(100, 100),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(-100, 200),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	final Picture picture = recorder.endRecording();
	builder.addPicture(const Offset(300, 300), picture);
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}
	}

	/// Two platform views without an overlay intersecting either platform view.
	class MultiPlatformViewWithoutOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	MultiPlatformViewWithoutOverlaysScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	builder.pushOffset(0, 600);
	_addPlatformViewtoScene(builder, 0, 500, 500);
	builder.pop();

	_addPlatformViewtoScene(builder, 1, 500, 500);

	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawRect(
	const Rect.fromLTRB(0, 0, 100, 1000),
	Paint()..color = const Color(0xFFFF0000),
	);
	final Picture picture = recorder.endRecording();
	builder.addPicture(const Offset(580, 0), picture);

	builder.pop();
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}
	}

	/// A simple platform view with too many overlays result in a single native view.
	class PlatformViewMaxOverlaysScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewMaxOverlaysScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	_addPlatformViewtoScene(builder, 0, 500, 500);
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawCircle(
	const Offset(50, 50),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(100, 100),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(-100, 200),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	canvas.drawCircle(
	const Offset(-100, -80),
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	final Picture picture = recorder.endRecording();
	builder.addPicture(const Offset(300, 300), picture);
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}
	}

	/// Builds a scene with 2 platform views.
	class MultiPlatformViewScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	MultiPlatformViewScenario(Window window, {this.firstId, this.secondId})
	: assert(window != null),
	super(window) {
	createPlatformView(window, 'platform view 1', firstId);
	createPlatformView(window, 'platform view 2', secondId);
	}

	/// The platform view identifier to use for the first platform view.
	final int firstId;

	/// The platform view identifier to use for the second platform view.
	final int secondId;

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	builder.pushOffset(0, 600);
	_addPlatformViewtoScene(builder, firstId, 500, 500);
	builder.pop();

	finishBuilderByAddingPlatformViewAndPicture(builder, secondId);
	}
	}

	/// Scenario for verifying platform views after background and foregrounding the app.
	///
	/// Renders a frame with 2 platform views covered by a flutter drawn rectangle,
	/// when the app goes to the background and comes back to the foreground renders a new frame
	/// with the 2 platform views but without the flutter drawn rectangle.
	class MultiPlatformViewBackgroundForegroundScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	MultiPlatformViewBackgroundForegroundScenario(Window window, {this.firstId, this.secondId})
	: assert(window != null),
	super(window) {
	createPlatformView(window, 'platform view 1', firstId);
	createPlatformView(window, 'platform view 2', secondId);
	_nextFrame = _firstFrame;
	}

	/// The platform view identifier to use for the first platform view.
	final int firstId;

	/// The platform view identifier to use for the second platform view.
	final int secondId;

	@override
	void onBeginFrame(Duration duration) {
	_nextFrame();
	}

	VoidCallback _nextFrame;

	void _firstFrame() {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	builder.pushOffset(0, 600);
	_addPlatformViewtoScene(builder, firstId, 500, 500);
	builder.pop();

	_addPlatformViewtoScene(builder, secondId, 500, 500);

	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawRect(
	const Rect.fromLTRB(0, 0, 500, 1000),
	Paint()..color = const Color(0xFFFF0000),
	);
	final Picture picture = recorder.endRecording();
	builder.addPicture(const Offset(0, 0), picture);

	builder.pop();
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}

	void _secondFrame() {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	builder.pushOffset(0, 600);
	_addPlatformViewtoScene(builder, firstId, 500, 500);
	builder.pop();

	_addPlatformViewtoScene(builder, secondId, 500, 500);
	final Scene scene = builder.build();
	window.render(scene);
	scene.dispose();
	}

	String _lastLifecycleState = '';

	@override
	void onPlatformMessage(
	String name,
	ByteData data,
	PlatformMessageResponseCallback callback,
	) {
	if (name != 'flutter/lifecycle') {
	return;
	}
	final String message = utf8.decode(data.buffer.asUint8List());
	if (_lastLifecycleState == 'AppLifecycleState.inactive' && message == 'AppLifecycleState.resumed') {
	_nextFrame = _secondFrame;
	window.scheduleFrame();
	}

	_lastLifecycleState = message;
	}
	}

	/// Platform view with clip rect.
	class PlatformViewClipRectScenario extends Scenario with _BasePlatformViewScenarioMixin {
	/// Constructs a platform view with clip rect scenario.
	PlatformViewClipRectScenario(Window window, String text, {int id = 0})
	: assert(window != null),
	super(window) {
	createPlatformView(window, text, id);
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();
	builder.pushOffset(0, 0);
	builder.pushClipRect(const Rect.fromLTRB(100, 100, 400, 400));
	finishBuilderByAddingPlatformViewAndPicture(builder, 1);
	}
	}

	/// Platform view with clip rrect.
	class PlatformViewClipRRectScenario extends PlatformViewScenario {
	/// Constructs a platform view with clip rrect scenario.
	PlatformViewClipRRectScenario(Window window, String text, {int id = 0})
	: super(window, text, id: id);

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);
	builder.pushClipRRect(
	RRect.fromLTRBAndCorners(
	100,
	100,
	400,
	400,
	topLeft: const Radius.circular(15),
	topRight: const Radius.circular(50),
	bottomLeft: const Radius.circular(50),
	),
	);
	finishBuilderByAddingPlatformViewAndPicture(builder, 2);
	}
	}

	/// Platform view with clip path.
	class PlatformViewClipPathScenario extends PlatformViewScenario {
	/// Constructs a platform view with clip rrect scenario.
	PlatformViewClipPathScenario(Window window, String text, {int id = 0})
	: super(window, text, id: id);

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);

	final Path path = Path()
	..moveTo(100, 100)
	..quadraticBezierTo(50, 250, 100, 400)
	..lineTo(350, 400)
	..cubicTo(400, 300, 300, 200, 350, 100)
	..close();
	builder.pushClipPath(path);

	finishBuilderByAddingPlatformViewAndPicture(builder, 3);
	}
	}

	/// Platform view with transform.
	class PlatformViewTransformScenario extends PlatformViewScenario {
	/// Constructs a platform view with transform scenario.
	PlatformViewTransformScenario(Window window, String text, {int id = 0})
	: super(window, text, id: id);

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);
	final Matrix4 matrix4 = Matrix4.identity()
	..rotateZ(1)
	..scale(0.5, 0.5, 1.0)
	..translate(1000.0, 100.0, 0.0);

	builder.pushTransform(matrix4.storage);

	finishBuilderByAddingPlatformViewAndPicture(builder, 4);
	}
	}

	/// Platform view with opacity.
	class PlatformViewOpacityScenario extends PlatformViewScenario {
	/// Constructs a platform view with transform scenario.
	PlatformViewOpacityScenario(Window window, String text, {int id = 0})
	: super(window, text, id: id);

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);
	builder.pushOpacity(150);

	finishBuilderByAddingPlatformViewAndPicture(builder, 5);
	}
	}

	/// A simple platform view for testing touch events from iOS.
	class PlatformViewForTouchIOSScenario extends Scenario
	with _BasePlatformViewScenarioMixin {

	int _viewId;
	bool _accept;
	/// Creates the PlatformView scenario.
	///
	/// The [window] parameter must not be null.
	PlatformViewForTouchIOSScenario(Window window, String text, {int id = 0, bool accept, bool rejectUntilTouchesEnded = false})
	: assert(window != null),
	_accept = accept,
	_viewId = id,
	super(window) {
	if (rejectUntilTouchesEnded) {
	createPlatformView(window, text, id, viewType: 'scenarios/textPlatformView_blockPolicyUntilTouchesEnded');
	} else {
	createPlatformView(window, text, id);
	}
	}

	@override
	void onBeginFrame(Duration duration) {
	final SceneBuilder builder = SceneBuilder();

	builder.pushOffset(0, 0);
	finishBuilderByAddingPlatformViewAndPicture(builder, 11);
	}

	@override
	void onPointerDataPacket(PointerDataPacket packet) {
	if (packet.data.first.change == PointerChange.add) {
	String method = 'rejectGesture';
	if (_accept) {
	method = 'acceptGesture';
	}
	const int _valueString = 7;
	const int _valueInt32 = 3;
	const int _valueMap = 13;
	final Uint8List message = Uint8List.fromList(<int>[
	_valueString,
	method.length,
	...utf8.encode(method),
	_valueMap,
	1,
	_valueString,
	'id'.length,
	...utf8.encode('id'),
	_valueInt32,
	..._to32(_viewId),
	]);
	window.sendPlatformMessage(
	'flutter/platform_views',
	message.buffer.asByteData(),
	(ByteData response) {},
	);
	}

	}
	}

	mixin _BasePlatformViewScenarioMixin on Scenario {
	int _textureId;

	/// Construct the platform view related scenario
	///
	/// It prepare a TextPlatformView so it can be added to the SceneBuilder in `onBeginFrame`.
	/// Call this method in the constructor of the platform view related scenarios
	/// to perform necessary set up.
	void createPlatformView(Window window, String text, int id, {String viewType = 'scenarios/textPlatformView'}) {
	const int _valueInt32 = 3;
	const int _valueFloat64 = 6;
	const int _valueString = 7;
	const int _valueUint8List = 8;
	const int _valueMap = 13;
	final Uint8List message = Uint8List.fromList(<int>[
	_valueString,
	'create'.length, // this won't work if we use multi-byte characters.
	...utf8.encode('create'),
	_valueMap,
	if (Platform.isIOS)
	3, // 3 entries in map for iOS.
	if (Platform.isAndroid)
	6, // 6 entries in map for Android.
	_valueString,
	'id'.length,
	...utf8.encode('id'),
	_valueInt32,
	..._to32(id),
	_valueString,
	'viewType'.length,
	...utf8.encode('viewType'),
	_valueString,
	viewType.length,
	...utf8.encode(viewType),
	if (Platform.isAndroid) ...<int>[
	_valueString,
	'width'.length,
	...utf8.encode('width'),
	_valueFloat64,
	..._to64(500.0),
	_valueString,
	'height'.length,
	...utf8.encode('height'),
	_valueFloat64,
	..._to64(500.0),
	_valueString,
	'direction'.length,
	...utf8.encode('direction'),
	_valueInt32,
	..._to32(0), // LTR
	],
	_valueString,
	'params'.length,
	...utf8.encode('params'),
	_valueUint8List,
	text.length,
	...utf8.encode(text),
	]);

	window.sendPlatformMessage(
	'flutter/platform_views',
	message.buffer.asByteData(),
	(ByteData response) {
	if (response != null && Platform.isAndroid) {
	// Envelope.
	_textureId = response.getUint8(0);
	}
	},
	);
	}

	void _addPlatformViewtoScene(
	SceneBuilder sceneBuilder,
	int viewId,
	double width,
	double height, {
	Offset overlayOffset,
	}) {
	overlayOffset ??= const Offset(50, 50);
	if (Platform.isIOS) {
	sceneBuilder.addPlatformView(viewId, offset: overlayOffset, width: width, height: height);
	} else if (Platform.isAndroid && _textureId != null) {
	sceneBuilder.addTexture(_textureId, offset: overlayOffset, width: width, height: height);
	} else {
	throw UnsupportedError('Platform ${Platform.operatingSystem} is not supported');
	}
	}

	// Add a platform view and a picture to the scene, then finish the `sceneBuilder`.
	void finishBuilderByAddingPlatformViewAndPicture(
	SceneBuilder sceneBuilder,
	int viewId, {
	Offset overlayOffset,
	}) {
	overlayOffset ??= const Offset(50, 50);
	_addPlatformViewtoScene(
	sceneBuilder,
	viewId,
	500,
	500,
	overlayOffset: overlayOffset,
	);
	final PictureRecorder recorder = PictureRecorder();
	final Canvas canvas = Canvas(recorder);
	canvas.drawCircle(
	overlayOffset,
	50,
	Paint()..color = const Color(0xFFABCDEF),
	);
	final Picture picture = recorder.endRecording();
	sceneBuilder.addPicture(const Offset(300, 300), picture);
	final Scene scene = sceneBuilder.build();
	window.render(scene);
	scene.dispose();
	}
	}