class AudioElementSound extends Sound {

 AudioElement _audio;
 List<AudioElement> _audioPool;
 List<AudioElementSoundChannel> _soundChannels;

 AudioElementSound() {

   _soundChannels = new List<AudioElementSoundChannel>();

   _audio = new AudioElement();
   _audio.onEnded.listen(_onAudioEnded);

   _audioPool = new List<AudioElement>();
   _audioPool.add(_audio);

   html.document.body.children.add(_audio);
 }

 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------

 static Future<Sound> load(String url, [SoundLoadOptions soundLoadOptions = null]) {

   if (soundLoadOptions == null) soundLoadOptions = Sound.defaultLoadOptions;

   var sound = new AudioElementSound();
   var audio = sound._audio;
   var audioUrls = SoundMixer._getOptimalAudioUrls(url, soundLoadOptions);
   var loadCompleter = new Completer<Sound>();

   if (audioUrls.length == 0) {
     return MockSound.load(url, soundLoadOptions);
   }

   StreamSubscription onCanPlayThroughSubscription;
   StreamSubscription onErrorSubscription;

   onCanPlayThrough(event) {
     onCanPlayThroughSubscription.cancel();
     onErrorSubscription.cancel();
     loadCompleter.complete(sound);
   };

   onError(event) {
     if (audioUrls.length > 0) {
       audio.src = audioUrls.removeAt(0);
       audio.load();
     } else {
       onCanPlayThroughSubscription.cancel();
       onErrorSubscription.cancel();

       if (soundLoadOptions.ignoreErrors) {
         MockSound.load(url, soundLoadOptions).then((s) => loadCompleter.complete(s));
       } else {
         loadCompleter.completeError(new StateError("Failed to load audio."));
       }
     }
   };

   onCanPlayThroughSubscription = audio.onCanPlayThrough.listen(onCanPlayThrough);
   onErrorSubscription = audio.onError.listen(onError);

   audio.src = audioUrls.removeAt(0);
   audio.load();

   return loadCompleter.future;
 }

 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------

 num get length => _audio.duration;

 SoundChannel play([bool loop = false, SoundTransform soundTransform]) {

   if (soundTransform == null) soundTransform = new SoundTransform();
   return new AudioElementSoundChannel(this, loop, soundTransform);
 }

 //-------------------------------------------------------------------------------------------------
 //-------------------------------------------------------------------------------------------------

 AudioElement _getAudioElement(AudioElementSoundChannel soundChannel) {

   AudioElement audio;

   if (_audioPool.length == 0) {
     audio = _audio.clone(true);
     audio.onEnded.listen(_onAudioEnded);
   } else {
     audio = _audioPool.removeAt(0);
   }

   SoundMixer._audioElementMixer._addSoundChannel(soundChannel);
   _soundChannels.add(soundChannel);

   return audio;
 }

 void _releaseAudioElement(AudioElementSoundChannel soundChannel) {

   SoundMixer._audioElementMixer._removeSoundChannel(soundChannel);
   _soundChannels.remove(soundChannel);

   AudioElement audio = soundChannel._audio;
   _audioPool.add(audio);

   if (audio.currentTime > 0 && audio.ended == false) {
     audio.currentTime = 0;
   }
 }

 void _onAudioEnded(html.Event event) {
   var audio = event.target;

   for(var i = 0; i < _soundChannels.length; i++) {
     if (identical(_soundChannels[i]._audio, audio)) {
       _soundChannels[i].stop();
       break;
     }
   }
 }

}