packages/video_player/lib/video_player.dart - mirrors/plugins - Git at Google

 // Copyright 2017 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 'dart:async';
 import 'dart:io';

 import 'package:flutter/services.dart';
 import 'package:flutter/material.dart';
 import 'package:meta/meta.dart';

 final MethodChannel _channel = const MethodChannel('flutter.io/videoPlayer')
   // This will clear all open videos on the platform when a full restart is
   // performed.
   // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
   // https://github.com/flutter/flutter/issues/26431
   // ignore: strong_mode_implicit_dynamic_method
   ..invokeMethod('init');

 class DurationRange {
   DurationRange(this.start, this.end);

   final Duration start;
   final Duration end;

   double startFraction(Duration duration) {
     return start.inMilliseconds / duration.inMilliseconds;
   }

   double endFraction(Duration duration) {
     return end.inMilliseconds / duration.inMilliseconds;
   }

   @override
   String toString() => '$runtimeType(start: $start, end: $end)';
 }

 /// The duration, current position, buffering state, error state and settings
 /// of a [VideoPlayerController].
 class VideoPlayerValue {
   VideoPlayerValue({
     @required this.duration,
     this.size,
     this.position = const Duration(),
     this.buffered = const <DurationRange>[],
     this.isPlaying = false,
     this.isLooping = false,
     this.isBuffering = false,
     this.volume = 1.0,
     this.errorDescription,
   });

   VideoPlayerValue.uninitialized() : this(duration: null);

   VideoPlayerValue.erroneous(String errorDescription)
       : this(duration: null, errorDescription: errorDescription);

   /// The total duration of the video.
   ///
   /// Is null when [initialized] is false.
   final Duration duration;

   /// The current playback position.
   final Duration position;

   /// The currently buffered ranges.
   final List<DurationRange> buffered;

   /// True if the video is playing. False if it's paused.
   final bool isPlaying;

   /// True if the video is looping.
   final bool isLooping;

   /// True if the video is currently buffering.
   final bool isBuffering;

   /// The current volume of the playback.
   final double volume;

   /// A description of the error if present.
   ///
   /// If [hasError] is false this is [null].
   final String errorDescription;

   /// The [size] of the currently loaded video.
   ///
   /// Is null when [initialized] is false.
   final Size size;

   bool get initialized => duration != null;
   bool get hasError => errorDescription != null;
   double get aspectRatio => size != null ? size.width / size.height : 1.0;

   VideoPlayerValue copyWith({
     Duration duration,
     Size size,
     Duration position,
     List<DurationRange> buffered,
     bool isPlaying,
     bool isLooping,
     bool isBuffering,
     double volume,
     String errorDescription,
   }) {
     return VideoPlayerValue(
       duration: duration ?? this.duration,
       size: size ?? this.size,
       position: position ?? this.position,
       buffered: buffered ?? this.buffered,
       isPlaying: isPlaying ?? this.isPlaying,
       isLooping: isLooping ?? this.isLooping,
       isBuffering: isBuffering ?? this.isBuffering,
       volume: volume ?? this.volume,
       errorDescription: errorDescription ?? this.errorDescription,
     );
   }

   @override
   String toString() {
     return '$runtimeType('
         'duration: $duration, '
         'size: $size, '
         'position: $position, '
         'buffered: [${buffered.join(', ')}], '
         'isPlaying: $isPlaying, '
         'isLooping: $isLooping, '
         'isBuffering: $isBuffering'
         'volume: $volume, '
         'errorDescription: $errorDescription)';
   }
 }

 enum DataSourceType { asset, network, file }

 /// Controls a platform video player, and provides updates when the state is
 /// changing.
 ///
 /// Instances must be initialized with initialize.
 ///
 /// The video is displayed in a Flutter app by creating a [VideoPlayer] widget.
 ///
 /// To reclaim the resources used by the player call [dispose].
 ///
 /// After [dispose] all further calls are ignored.
 class VideoPlayerController extends ValueNotifier<VideoPlayerValue> {
   /// Constructs a [VideoPlayerController] playing a video from an asset.
   ///
   /// The name of the asset is given by the [dataSource] argument and must not be
   /// null. The [package] argument must be non-null when the asset comes from a
   /// package and null otherwise.
   VideoPlayerController.asset(this.dataSource, {this.package})
       : dataSourceType = DataSourceType.asset,
         super(VideoPlayerValue(duration: null));

   /// Constructs a [VideoPlayerController] playing a video from obtained from
   /// the network.
   ///
   /// The URI for the video is given by the [dataSource] argument and must not be
   /// null.
   VideoPlayerController.network(this.dataSource)
       : dataSourceType = DataSourceType.network,
         package = null,
         super(VideoPlayerValue(duration: null));

   /// Constructs a [VideoPlayerController] playing a video from a file.
   ///
   /// This will load the file from the file-URI given by:
   /// `'file://${file.path}'`.
   VideoPlayerController.file(File file)
       : dataSource = 'file://${file.path}',
         dataSourceType = DataSourceType.file,
         package = null,
         super(VideoPlayerValue(duration: null));

   int _textureId;
   final String dataSource;

   /// Describes the type of data source this [VideoPlayerController]
   /// is constructed with.
   final DataSourceType dataSourceType;

   final String package;
   Timer _timer;
   bool _isDisposed = false;
   Completer<void> _creatingCompleter;
   StreamSubscription<dynamic> _eventSubscription;
   _VideoAppLifeCycleObserver _lifeCycleObserver;

   @visibleForTesting
   int get textureId => _textureId;

   Future<void> initialize() async {
     _lifeCycleObserver = _VideoAppLifeCycleObserver(this);
     _lifeCycleObserver.initialize();
     _creatingCompleter = Completer<void>();
     Map<dynamic, dynamic> dataSourceDescription;
     switch (dataSourceType) {
       case DataSourceType.asset:
         dataSourceDescription = <String, dynamic>{
           'asset': dataSource,
           'package': package
         };
         break;
       case DataSourceType.network:
         dataSourceDescription = <String, dynamic>{'uri': dataSource};
         break;
       case DataSourceType.file:
         dataSourceDescription = <String, dynamic>{'uri': dataSource};
     }
     // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
     // https://github.com/flutter/flutter/issues/26431
     // ignore: strong_mode_implicit_dynamic_method
     final Map<dynamic, dynamic> response = await _channel.invokeMethod(
       'create',
       dataSourceDescription,
     );
     _textureId = response['textureId'];
     _creatingCompleter.complete(null);
     final Completer<void> initializingCompleter = Completer<void>();

     DurationRange toDurationRange(dynamic value) {
       final List<dynamic> pair = value;
       return DurationRange(
         Duration(milliseconds: pair[0]),
         Duration(milliseconds: pair[1]),
       );
     }

     void eventListener(dynamic event) {
       final Map<dynamic, dynamic> map = event;
       switch (map['event']) {
         case 'initialized':
           value = value.copyWith(
             duration: Duration(milliseconds: map['duration']),
             size: Size(map['width']?.toDouble() ?? 0.0,
                 map['height']?.toDouble() ?? 0.0),
           );
           initializingCompleter.complete(null);
           _applyLooping();
           _applyVolume();
           _applyPlayPause();
           break;
         case 'completed':
           value = value.copyWith(isPlaying: false, position: value.duration);
           _timer?.cancel();
           break;
         case 'bufferingUpdate':
           final List<dynamic> values = map['values'];
           value = value.copyWith(
             buffered: values.map<DurationRange>(toDurationRange).toList(),
           );
           break;
         case 'bufferingStart':
           value = value.copyWith(isBuffering: true);
           break;
         case 'bufferingEnd':
           value = value.copyWith(isBuffering: false);
           break;
       }
     }

     void errorListener(Object obj) {
       final PlatformException e = obj;
       value = VideoPlayerValue.erroneous(e.message);
       _timer?.cancel();
     }

     _eventSubscription = _eventChannelFor(_textureId)
         .receiveBroadcastStream()
         .listen(eventListener, onError: errorListener);
     return initializingCompleter.future;
   }

   EventChannel _eventChannelFor(int textureId) {
     return EventChannel('flutter.io/videoPlayer/videoEvents$textureId');
   }

   @override
   Future<void> dispose() async {
     if (_creatingCompleter != null) {
       await _creatingCompleter.future;
       if (!_isDisposed) {
         _isDisposed = true;
         _timer?.cancel();
         await _eventSubscription?.cancel();
         // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
         // https://github.com/flutter/flutter/issues/26431
         // ignore: strong_mode_implicit_dynamic_method
         await _channel.invokeMethod(
           'dispose',
           <String, dynamic>{'textureId': _textureId},
         );
       }
       _lifeCycleObserver.dispose();
     }
     _isDisposed = true;
     super.dispose();
   }

   Future<void> play() async {
     value = value.copyWith(isPlaying: true);
     await _applyPlayPause();
   }

   Future<void> setLooping(bool looping) async {
     value = value.copyWith(isLooping: looping);
     await _applyLooping();
   }

   Future<void> pause() async {
     value = value.copyWith(isPlaying: false);
     await _applyPlayPause();
   }

   Future<void> _applyLooping() async {
     if (!value.initialized || _isDisposed) {
       return;
     }
     // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
     // https://github.com/flutter/flutter/issues/26431
     // ignore: strong_mode_implicit_dynamic_method
     _channel.invokeMethod(
       'setLooping',
       <String, dynamic>{'textureId': _textureId, 'looping': value.isLooping},
     );
   }

   Future<void> _applyPlayPause() async {
     if (!value.initialized || _isDisposed) {
       return;
     }
     if (value.isPlaying) {
       // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
       // https://github.com/flutter/flutter/issues/26431
       // ignore: strong_mode_implicit_dynamic_method
       await _channel.invokeMethod(
         'play',
         <String, dynamic>{'textureId': _textureId},
       );
       _timer = Timer.periodic(
         const Duration(milliseconds: 500),
         (Timer timer) async {
           if (_isDisposed) {
             return;
           }
           final Duration newPosition = await position;
           if (_isDisposed) {
             return;
           }
           value = value.copyWith(position: newPosition);
         },
       );
     } else {
       _timer?.cancel();
       // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
       // https://github.com/flutter/flutter/issues/26431
       // ignore: strong_mode_implicit_dynamic_method
       await _channel.invokeMethod(
         'pause',
         <String, dynamic>{'textureId': _textureId},
       );
     }
   }

   Future<void> _applyVolume() async {
     if (!value.initialized || _isDisposed) {
       return;
     }
     // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
     // https://github.com/flutter/flutter/issues/26431
     // ignore: strong_mode_implicit_dynamic_method
     await _channel.invokeMethod(
       'setVolume',
       <String, dynamic>{'textureId': _textureId, 'volume': value.volume},
     );
   }

   /// The position in the current video.
   Future<Duration> get position async {
     if (_isDisposed) {
       return null;
     }
     return Duration(
       // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
       // https://github.com/flutter/flutter/issues/26431
       // ignore: strong_mode_implicit_dynamic_method
       milliseconds: await _channel.invokeMethod(
         'position',
         <String, dynamic>{'textureId': _textureId},
       ),
     );
   }

   Future<void> seekTo(Duration moment) async {
     if (_isDisposed) {
       return;
     }
     if (moment > value.duration) {
       moment = value.duration;
     } else if (moment < const Duration()) {
       moment = const Duration();
     }
     // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
     // https://github.com/flutter/flutter/issues/26431
     // ignore: strong_mode_implicit_dynamic_method
     await _channel.invokeMethod('seekTo', <String, dynamic>{
       'textureId': _textureId,
       'location': moment.inMilliseconds,
     });
     value = value.copyWith(position: moment);
   }

   /// Sets the audio volume of [this].
   ///
   /// [volume] indicates a value between 0.0 (silent) and 1.0 (full volume) on a
   /// linear scale.
   Future<void> setVolume(double volume) async {
     value = value.copyWith(volume: volume.clamp(0.0, 1.0));
     await _applyVolume();
   }
 }

 class _VideoAppLifeCycleObserver extends Object with WidgetsBindingObserver {
   _VideoAppLifeCycleObserver(this._controller);

   bool _wasPlayingBeforePause = false;
   final VideoPlayerController _controller;

   void initialize() {
     WidgetsBinding.instance.addObserver(this);
   }

   @override
   void didChangeAppLifecycleState(AppLifecycleState state) {
     switch (state) {
       case AppLifecycleState.paused:
         _wasPlayingBeforePause = _controller.value.isPlaying;
         _controller.pause();
         break;
       case AppLifecycleState.resumed:
         if (_wasPlayingBeforePause) {
           _controller.play();
         }
         break;
       default:
     }
   }

   void dispose() {
     WidgetsBinding.instance.removeObserver(this);
   }
 }

 /// Displays the video controlled by [controller].
 class VideoPlayer extends StatefulWidget {
   VideoPlayer(this.controller);

   final VideoPlayerController controller;

   @override
   _VideoPlayerState createState() => _VideoPlayerState();
 }

 class _VideoPlayerState extends State<VideoPlayer> {
   _VideoPlayerState() {
     _listener = () {
       final int newTextureId = widget.controller.textureId;
       if (newTextureId != _textureId) {
         setState(() {
           _textureId = newTextureId;
         });
       }
     };
   }

   VoidCallback _listener;
   int _textureId;

   @override
   void initState() {
     super.initState();
     _textureId = widget.controller.textureId;
     // Need to listen for initialization events since the actual texture ID
     // becomes available after asynchronous initialization finishes.
     widget.controller.addListener(_listener);
   }

   @override
   void didUpdateWidget(VideoPlayer oldWidget) {
     super.didUpdateWidget(oldWidget);
     oldWidget.controller.removeListener(_listener);
     _textureId = widget.controller.textureId;
     widget.controller.addListener(_listener);
   }

   @override
   void deactivate() {
     super.deactivate();
     widget.controller.removeListener(_listener);
   }

   @override
   Widget build(BuildContext context) {
     return _textureId == null ? Container() : Texture(textureId: _textureId);
   }
 }

 class VideoProgressColors {
   VideoProgressColors({
     this.playedColor = const Color.fromRGBO(255, 0, 0, 0.7),
     this.bufferedColor = const Color.fromRGBO(50, 50, 200, 0.2),
     this.backgroundColor = const Color.fromRGBO(200, 200, 200, 0.5),
   });

   final Color playedColor;
   final Color bufferedColor;
   final Color backgroundColor;
 }

 class _VideoScrubber extends StatefulWidget {
   _VideoScrubber({
     @required this.child,
     @required this.controller,
   });

   final Widget child;
   final VideoPlayerController controller;

   @override
   _VideoScrubberState createState() => _VideoScrubberState();
 }

 class _VideoScrubberState extends State<_VideoScrubber> {
   bool _controllerWasPlaying = false;

   VideoPlayerController get controller => widget.controller;

   @override
   Widget build(BuildContext context) {
     void seekToRelativePosition(Offset globalPosition) {
       final RenderBox box = context.findRenderObject();
       final Offset tapPos = box.globalToLocal(globalPosition);
       final double relative = tapPos.dx / box.size.width;
       final Duration position = controller.value.duration * relative;
       controller.seekTo(position);
     }

     return GestureDetector(
       behavior: HitTestBehavior.opaque,
       child: widget.child,
       onHorizontalDragStart: (DragStartDetails details) {
         if (!controller.value.initialized) {
           return;
         }
         _controllerWasPlaying = controller.value.isPlaying;
         if (_controllerWasPlaying) {
           controller.pause();
         }
       },
       onHorizontalDragUpdate: (DragUpdateDetails details) {
         if (!controller.value.initialized) {
           return;
         }
         seekToRelativePosition(details.globalPosition);
       },
       onHorizontalDragEnd: (DragEndDetails details) {
         if (_controllerWasPlaying) {
           controller.play();
         }
       },
       onTapDown: (TapDownDetails details) {
         if (!controller.value.initialized) {
           return;
         }
         seekToRelativePosition(details.globalPosition);
       },
     );
   }
 }

 /// Displays the play/buffering status of the video controlled by [controller].
 ///
 /// If [allowScrubbing] is true, this widget will detect taps and drags and
 /// seek the video accordingly.
 ///
 /// [padding] allows to specify some extra padding around the progress indicator
 /// that will also detect the gestures.
 class VideoProgressIndicator extends StatefulWidget {
   VideoProgressIndicator(
     this.controller, {
     VideoProgressColors colors,
     this.allowScrubbing,
     this.padding = const EdgeInsets.only(top: 5.0),
   }) : colors = colors ?? VideoProgressColors();

   final VideoPlayerController controller;
   final VideoProgressColors colors;
   final bool allowScrubbing;
   final EdgeInsets padding;

   @override
   _VideoProgressIndicatorState createState() => _VideoProgressIndicatorState();
 }

 class _VideoProgressIndicatorState extends State<VideoProgressIndicator> {
   _VideoProgressIndicatorState() {
     listener = () {
       if (!mounted) {
         return;
       }
       setState(() {});
     };
   }

   VoidCallback listener;

   VideoPlayerController get controller => widget.controller;

   VideoProgressColors get colors => widget.colors;

   @override
   void initState() {
     super.initState();
     controller.addListener(listener);
   }

   @override
   void deactivate() {
     controller.removeListener(listener);
     super.deactivate();
   }

   @override
   Widget build(BuildContext context) {
     Widget progressIndicator;
     if (controller.value.initialized) {
       final int duration = controller.value.duration.inMilliseconds;
       final int position = controller.value.position.inMilliseconds;

       int maxBuffering = 0;
       for (DurationRange range in controller.value.buffered) {
         final int end = range.end.inMilliseconds;
         if (end > maxBuffering) {
           maxBuffering = end;
         }
       }

       progressIndicator = Stack(
         fit: StackFit.passthrough,
         children: <Widget>[
           LinearProgressIndicator(
             value: maxBuffering / duration,
             valueColor: AlwaysStoppedAnimation<Color>(colors.bufferedColor),
             backgroundColor: colors.backgroundColor,
           ),
           LinearProgressIndicator(
             value: position / duration,
             valueColor: AlwaysStoppedAnimation<Color>(colors.playedColor),
             backgroundColor: Colors.transparent,
           ),
         ],
       );
     } else {
       progressIndicator = LinearProgressIndicator(
         value: null,
         valueColor: AlwaysStoppedAnimation<Color>(colors.playedColor),
         backgroundColor: colors.backgroundColor,
       );
     }
     final Widget paddedProgressIndicator = Padding(
       padding: widget.padding,
       child: progressIndicator,
     );
     if (widget.allowScrubbing) {
       return _VideoScrubber(
         child: paddedProgressIndicator,
         controller: controller,
       );
     } else {
       return paddedProgressIndicator;
     }
   }
 }
	// Copyright 2017 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 'dart:async';
	import 'dart:io';

	import 'package:flutter/services.dart';
	import 'package:flutter/material.dart';
	import 'package:meta/meta.dart';

	final MethodChannel _channel = const MethodChannel('flutter.io/videoPlayer')
	// This will clear all open videos on the platform when a full restart is
	// performed.
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	..invokeMethod('init');

	class DurationRange {
	DurationRange(this.start, this.end);

	final Duration start;
	final Duration end;

	double startFraction(Duration duration) {
	return start.inMilliseconds / duration.inMilliseconds;
	}

	double endFraction(Duration duration) {
	return end.inMilliseconds / duration.inMilliseconds;
	}

	@override
	String toString() => '$runtimeType(start: $start, end: $end)';
	}

	/// The duration, current position, buffering state, error state and settings
	/// of a [VideoPlayerController].
	class VideoPlayerValue {
	VideoPlayerValue({
	@required this.duration,
	this.size,
	this.position = const Duration(),
	this.buffered = const <DurationRange>[],
	this.isPlaying = false,
	this.isLooping = false,
	this.isBuffering = false,
	this.volume = 1.0,
	this.errorDescription,
	});

	VideoPlayerValue.uninitialized() : this(duration: null);

	VideoPlayerValue.erroneous(String errorDescription)
	: this(duration: null, errorDescription: errorDescription);

	/// The total duration of the video.
	///
	/// Is null when [initialized] is false.
	final Duration duration;

	/// The current playback position.
	final Duration position;

	/// The currently buffered ranges.
	final List<DurationRange> buffered;

	/// True if the video is playing. False if it's paused.
	final bool isPlaying;

	/// True if the video is looping.
	final bool isLooping;

	/// True if the video is currently buffering.
	final bool isBuffering;

	/// The current volume of the playback.
	final double volume;

	/// A description of the error if present.
	///
	/// If [hasError] is false this is [null].
	final String errorDescription;

	/// The [size] of the currently loaded video.
	///
	/// Is null when [initialized] is false.
	final Size size;

	bool get initialized => duration != null;
	bool get hasError => errorDescription != null;
	double get aspectRatio => size != null ? size.width / size.height : 1.0;

	VideoPlayerValue copyWith({
	Duration duration,
	Size size,
	Duration position,
	List<DurationRange> buffered,
	bool isPlaying,
	bool isLooping,
	bool isBuffering,
	double volume,
	String errorDescription,
	}) {
	return VideoPlayerValue(
	duration: duration ?? this.duration,
	size: size ?? this.size,
	position: position ?? this.position,
	buffered: buffered ?? this.buffered,
	isPlaying: isPlaying ?? this.isPlaying,
	isLooping: isLooping ?? this.isLooping,
	isBuffering: isBuffering ?? this.isBuffering,
	volume: volume ?? this.volume,
	errorDescription: errorDescription ?? this.errorDescription,
	);
	}

	@override
	String toString() {
	return '$runtimeType('
	'duration: $duration, '
	'size: $size, '
	'position: $position, '
	'buffered: [${buffered.join(', ')}], '
	'isPlaying: $isPlaying, '
	'isLooping: $isLooping, '
	'isBuffering: $isBuffering'
	'volume: $volume, '
	'errorDescription: $errorDescription)';
	}
	}

	enum DataSourceType { asset, network, file }

	/// Controls a platform video player, and provides updates when the state is
	/// changing.
	///
	/// Instances must be initialized with initialize.
	///
	/// The video is displayed in a Flutter app by creating a [VideoPlayer] widget.
	///
	/// To reclaim the resources used by the player call [dispose].
	///
	/// After [dispose] all further calls are ignored.
	class VideoPlayerController extends ValueNotifier<VideoPlayerValue> {
	/// Constructs a [VideoPlayerController] playing a video from an asset.
	///
	/// The name of the asset is given by the [dataSource] argument and must not be
	/// null. The [package] argument must be non-null when the asset comes from a
	/// package and null otherwise.
	VideoPlayerController.asset(this.dataSource, {this.package})
	: dataSourceType = DataSourceType.asset,
	super(VideoPlayerValue(duration: null));

	/// Constructs a [VideoPlayerController] playing a video from obtained from
	/// the network.
	///
	/// The URI for the video is given by the [dataSource] argument and must not be
	/// null.
	VideoPlayerController.network(this.dataSource)
	: dataSourceType = DataSourceType.network,
	package = null,
	super(VideoPlayerValue(duration: null));

	/// Constructs a [VideoPlayerController] playing a video from a file.
	///
	/// This will load the file from the file-URI given by:
	/// `'file://${file.path}'`.
	VideoPlayerController.file(File file)
	: dataSource = 'file://${file.path}',
	dataSourceType = DataSourceType.file,
	package = null,
	super(VideoPlayerValue(duration: null));

	int _textureId;
	final String dataSource;

	/// Describes the type of data source this [VideoPlayerController]
	/// is constructed with.
	final DataSourceType dataSourceType;

	final String package;
	Timer _timer;
	bool _isDisposed = false;
	Completer<void> _creatingCompleter;
	StreamSubscription<dynamic> _eventSubscription;
	_VideoAppLifeCycleObserver _lifeCycleObserver;

	@visibleForTesting
	int get textureId => _textureId;

	Future<void> initialize() async {
	_lifeCycleObserver = _VideoAppLifeCycleObserver(this);
	_lifeCycleObserver.initialize();
	_creatingCompleter = Completer<void>();
	Map<dynamic, dynamic> dataSourceDescription;
	switch (dataSourceType) {
	case DataSourceType.asset:
	dataSourceDescription = <String, dynamic>{
	'asset': dataSource,
	'package': package
	};
	break;
	case DataSourceType.network:
	dataSourceDescription = <String, dynamic>{'uri': dataSource};
	break;
	case DataSourceType.file:
	dataSourceDescription = <String, dynamic>{'uri': dataSource};
	}
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	final Map<dynamic, dynamic> response = await _channel.invokeMethod(
	'create',
	dataSourceDescription,
	);
	_textureId = response['textureId'];
	_creatingCompleter.complete(null);
	final Completer<void> initializingCompleter = Completer<void>();

	DurationRange toDurationRange(dynamic value) {
	final List<dynamic> pair = value;
	return DurationRange(
	Duration(milliseconds: pair[0]),
	Duration(milliseconds: pair[1]),
	);
	}

	void eventListener(dynamic event) {
	final Map<dynamic, dynamic> map = event;
	switch (map['event']) {
	case 'initialized':
	value = value.copyWith(
	duration: Duration(milliseconds: map['duration']),
	size: Size(map['width']?.toDouble() ?? 0.0,
	map['height']?.toDouble() ?? 0.0),
	);
	initializingCompleter.complete(null);
	_applyLooping();
	_applyVolume();
	_applyPlayPause();
	break;
	case 'completed':
	value = value.copyWith(isPlaying: false, position: value.duration);
	_timer?.cancel();
	break;
	case 'bufferingUpdate':
	final List<dynamic> values = map['values'];
	value = value.copyWith(
	buffered: values.map<DurationRange>(toDurationRange).toList(),
	);
	break;
	case 'bufferingStart':
	value = value.copyWith(isBuffering: true);
	break;
	case 'bufferingEnd':
	value = value.copyWith(isBuffering: false);
	break;
	}
	}

	void errorListener(Object obj) {
	final PlatformException e = obj;
	value = VideoPlayerValue.erroneous(e.message);
	_timer?.cancel();
	}

	_eventSubscription = _eventChannelFor(_textureId)
	.receiveBroadcastStream()
	.listen(eventListener, onError: errorListener);
	return initializingCompleter.future;
	}

	EventChannel _eventChannelFor(int textureId) {
	return EventChannel('flutter.io/videoPlayer/videoEvents$textureId');
	}

	@override
	Future<void> dispose() async {
	if (_creatingCompleter != null) {
	await _creatingCompleter.future;
	if (!_isDisposed) {
	_isDisposed = true;
	_timer?.cancel();
	await _eventSubscription?.cancel();
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	await _channel.invokeMethod(
	'dispose',
	<String, dynamic>{'textureId': _textureId},
	);
	}
	_lifeCycleObserver.dispose();
	}
	_isDisposed = true;
	super.dispose();
	}

	Future<void> play() async {
	value = value.copyWith(isPlaying: true);
	await _applyPlayPause();
	}

	Future<void> setLooping(bool looping) async {
	value = value.copyWith(isLooping: looping);
	await _applyLooping();
	}

	Future<void> pause() async {
	value = value.copyWith(isPlaying: false);
	await _applyPlayPause();
	}

	Future<void> _applyLooping() async {
	if (!value.initialized \|\| _isDisposed) {
	return;
	}
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	_channel.invokeMethod(
	'setLooping',
	<String, dynamic>{'textureId': _textureId, 'looping': value.isLooping},
	);
	}

	Future<void> _applyPlayPause() async {
	if (!value.initialized \|\| _isDisposed) {
	return;
	}
	if (value.isPlaying) {
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	await _channel.invokeMethod(
	'play',
	<String, dynamic>{'textureId': _textureId},
	);
	_timer = Timer.periodic(
	const Duration(milliseconds: 500),
	(Timer timer) async {
	if (_isDisposed) {
	return;
	}
	final Duration newPosition = await position;
	if (_isDisposed) {
	return;
	}
	value = value.copyWith(position: newPosition);
	},
	);
	} else {
	_timer?.cancel();
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	await _channel.invokeMethod(
	'pause',
	<String, dynamic>{'textureId': _textureId},
	);
	}
	}

	Future<void> _applyVolume() async {
	if (!value.initialized \|\| _isDisposed) {
	return;
	}
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	await _channel.invokeMethod(
	'setVolume',
	<String, dynamic>{'textureId': _textureId, 'volume': value.volume},
	);
	}

	/// The position in the current video.
	Future<Duration> get position async {
	if (_isDisposed) {
	return null;
	}
	return Duration(
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	milliseconds: await _channel.invokeMethod(
	'position',
	<String, dynamic>{'textureId': _textureId},
	),
	);
	}

	Future<void> seekTo(Duration moment) async {
	if (_isDisposed) {
	return;
	}
	if (moment > value.duration) {
	moment = value.duration;
	} else if (moment < const Duration()) {
	moment = const Duration();
	}
	// TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
	// https://github.com/flutter/flutter/issues/26431
	// ignore: strong_mode_implicit_dynamic_method
	await _channel.invokeMethod('seekTo', <String, dynamic>{
	'textureId': _textureId,
	'location': moment.inMilliseconds,
	});
	value = value.copyWith(position: moment);
	}

	/// Sets the audio volume of [this].
	///
	/// [volume] indicates a value between 0.0 (silent) and 1.0 (full volume) on a
	/// linear scale.
	Future<void> setVolume(double volume) async {
	value = value.copyWith(volume: volume.clamp(0.0, 1.0));
	await _applyVolume();
	}
	}

	class _VideoAppLifeCycleObserver extends Object with WidgetsBindingObserver {
	_VideoAppLifeCycleObserver(this._controller);

	bool _wasPlayingBeforePause = false;
	final VideoPlayerController _controller;

	void initialize() {
	WidgetsBinding.instance.addObserver(this);
	}

	@override
	void didChangeAppLifecycleState(AppLifecycleState state) {
	switch (state) {
	case AppLifecycleState.paused:
	_wasPlayingBeforePause = _controller.value.isPlaying;
	_controller.pause();
	break;
	case AppLifecycleState.resumed:
	if (_wasPlayingBeforePause) {
	_controller.play();
	}
	break;
	default:
	}
	}

	void dispose() {
	WidgetsBinding.instance.removeObserver(this);
	}
	}

	/// Displays the video controlled by [controller].
	class VideoPlayer extends StatefulWidget {
	VideoPlayer(this.controller);

	final VideoPlayerController controller;

	@override
	_VideoPlayerState createState() => _VideoPlayerState();
	}

	class _VideoPlayerState extends State<VideoPlayer> {
	_VideoPlayerState() {
	_listener = () {
	final int newTextureId = widget.controller.textureId;
	if (newTextureId != _textureId) {
	setState(() {
	_textureId = newTextureId;
	});
	}
	};
	}

	VoidCallback _listener;
	int _textureId;

	@override
	void initState() {
	super.initState();
	_textureId = widget.controller.textureId;
	// Need to listen for initialization events since the actual texture ID
	// becomes available after asynchronous initialization finishes.
	widget.controller.addListener(_listener);
	}

	@override
	void didUpdateWidget(VideoPlayer oldWidget) {
	super.didUpdateWidget(oldWidget);
	oldWidget.controller.removeListener(_listener);
	_textureId = widget.controller.textureId;
	widget.controller.addListener(_listener);
	}

	@override
	void deactivate() {
	super.deactivate();
	widget.controller.removeListener(_listener);
	}

	@override
	Widget build(BuildContext context) {
	return _textureId == null ? Container() : Texture(textureId: _textureId);
	}
	}

	class VideoProgressColors {
	VideoProgressColors({
	this.playedColor = const Color.fromRGBO(255, 0, 0, 0.7),
	this.bufferedColor = const Color.fromRGBO(50, 50, 200, 0.2),
	this.backgroundColor = const Color.fromRGBO(200, 200, 200, 0.5),
	});

	final Color playedColor;
	final Color bufferedColor;
	final Color backgroundColor;
	}

	class _VideoScrubber extends StatefulWidget {
	_VideoScrubber({
	@required this.child,
	@required this.controller,
	});

	final Widget child;
	final VideoPlayerController controller;

	@override
	_VideoScrubberState createState() => _VideoScrubberState();
	}

	class _VideoScrubberState extends State<_VideoScrubber> {
	bool _controllerWasPlaying = false;

	VideoPlayerController get controller => widget.controller;

	@override
	Widget build(BuildContext context) {
	void seekToRelativePosition(Offset globalPosition) {
	final RenderBox box = context.findRenderObject();
	final Offset tapPos = box.globalToLocal(globalPosition);
	final double relative = tapPos.dx / box.size.width;
	final Duration position = controller.value.duration * relative;
	controller.seekTo(position);
	}

	return GestureDetector(
	behavior: HitTestBehavior.opaque,
	child: widget.child,
	onHorizontalDragStart: (DragStartDetails details) {
	if (!controller.value.initialized) {
	return;
	}
	_controllerWasPlaying = controller.value.isPlaying;
	if (_controllerWasPlaying) {
	controller.pause();
	}
	},
	onHorizontalDragUpdate: (DragUpdateDetails details) {
	if (!controller.value.initialized) {
	return;
	}
	seekToRelativePosition(details.globalPosition);
	},
	onHorizontalDragEnd: (DragEndDetails details) {
	if (_controllerWasPlaying) {
	controller.play();
	}
	},
	onTapDown: (TapDownDetails details) {
	if (!controller.value.initialized) {
	return;
	}
	seekToRelativePosition(details.globalPosition);
	},
	);
	}
	}

	/// Displays the play/buffering status of the video controlled by [controller].
	///
	/// If [allowScrubbing] is true, this widget will detect taps and drags and
	/// seek the video accordingly.
	///
	/// [padding] allows to specify some extra padding around the progress indicator
	/// that will also detect the gestures.
	class VideoProgressIndicator extends StatefulWidget {
	VideoProgressIndicator(
	this.controller, {
	VideoProgressColors colors,
	this.allowScrubbing,
	this.padding = const EdgeInsets.only(top: 5.0),
	}) : colors = colors ?? VideoProgressColors();

	final VideoPlayerController controller;
	final VideoProgressColors colors;
	final bool allowScrubbing;
	final EdgeInsets padding;

	@override
	_VideoProgressIndicatorState createState() => _VideoProgressIndicatorState();
	}

	class _VideoProgressIndicatorState extends State<VideoProgressIndicator> {
	_VideoProgressIndicatorState() {
	listener = () {
	if (!mounted) {
	return;
	}
	setState(() {});
	};
	}

	VoidCallback listener;

	VideoPlayerController get controller => widget.controller;

	VideoProgressColors get colors => widget.colors;

	@override
	void initState() {
	super.initState();
	controller.addListener(listener);
	}

	@override
	void deactivate() {
	controller.removeListener(listener);
	super.deactivate();
	}

	@override
	Widget build(BuildContext context) {
	Widget progressIndicator;
	if (controller.value.initialized) {
	final int duration = controller.value.duration.inMilliseconds;
	final int position = controller.value.position.inMilliseconds;

	int maxBuffering = 0;
	for (DurationRange range in controller.value.buffered) {
	final int end = range.end.inMilliseconds;
	if (end > maxBuffering) {
	maxBuffering = end;
	}
	}

	progressIndicator = Stack(
	fit: StackFit.passthrough,
	children: <Widget>[
	LinearProgressIndicator(
	value: maxBuffering / duration,
	valueColor: AlwaysStoppedAnimation<Color>(colors.bufferedColor),
	backgroundColor: colors.backgroundColor,
	),
	LinearProgressIndicator(
	value: position / duration,
	valueColor: AlwaysStoppedAnimation<Color>(colors.playedColor),
	backgroundColor: Colors.transparent,
	),
	],
	);
	} else {
	progressIndicator = LinearProgressIndicator(
	value: null,
	valueColor: AlwaysStoppedAnimation<Color>(colors.playedColor),
	backgroundColor: colors.backgroundColor,
	);
	}
	final Widget paddedProgressIndicator = Padding(
	padding: widget.padding,
	child: progressIndicator,
	);
	if (widget.allowScrubbing) {
	return _VideoScrubber(
	child: paddedProgressIndicator,
	controller: controller,
	);
	} else {
	return paddedProgressIndicator;
	}
	}
	}