An AudioClip stores sound data. To play an AudioClip, see AudioSource, AudioMusic, and AudioManager.

class AudioClip {
 static const SFXR_PREFIX = "sfxr:";

 final AudioManager _manager;
 String _name;
 String _url;
 set url(String u) => _url = u;
 String get url => _url;
 AudioBuffer _buffer;
 bool _hasError = false;
 String _errorString = '';
 bool _isReadyToPlay = false;
 bool _urlAbsolute = false;

 AudioClip._internal(this._manager, this._name, this._url);
 AudioClip.external(this._manager, this._name, this._url) {
   _urlAbsolute = true;
 }

 void _empty() {
   _isReadyToPlay = false;
   _buffer = null;
 }

 Map toJson() {
   // Serialize buffer contents as well.
   return {
     "_url":_url,
     "_name": _name,
   };
 }

 AudioClip fromMap(Map map) {
   _url = map['_url'];
   _name = map['_name'];
   return this;
 }

 /** Does the clip have an error? */
 bool get hasError => _hasError;
 /** Human readable error */
 String get errorString => _errorString;

 /** Clear any error. */
 void clearError() {
   _hasError = false;
   _errorString = 'OK';
 }

 void _setError(String error) {
   _hasError = true;
   _errorString = error;
 }

 void _onDecode(AudioBuffer buffer, Completer<AudioClip> completer) {
   if (buffer == null) {
     _setError('Error decoding buffer.');
     completer.complete(this);
     return;
   }
   clearError();
   _buffer = buffer;
   _isReadyToPlay = true;
   completer.complete(this);
 }

 void _onRequestSuccess(HttpRequest request, Completer<AudioClip> completer) {
   var response = request.response;
   _manager._context.decodeAudioData(response,
                                     (b) => _onDecode(b, completer),
                                     (b) => _onDecode(b, completer));
 }

 void _onRequestError(HttpRequest request, Completer<AudioClip> completer) {
   _setError('Error fetching data');
   completer.complete(this);
 }

 /** Fetch and decode the clip's [url] into the clip buffer.
  * Returns a [Future<AudioClip>] which completes to *this*.
  * [hasError] and [errorString] will indicate and explain respetively
  * any load errors.
  */
 Future<AudioClip> load() {
   if (url == null) {
     _setError('No URL set.');
     return new Future<AudioClip>.value(this);
   }
   _empty();
   if (url.startsWith(SFXR_PREFIX)) {
     return new Future<AudioClip>.delayed(new Duration(milliseconds: 1), (){
       _buffer = SfxrSynth.toAudioBuffer(_manager._context, url.substring(SFXR_PREFIX.length));
       _isReadyToPlay = true;
       return this;
     });
   }
   var request = new HttpRequest();
   var completer = new Completer<AudioClip>();
   if (_urlAbsolute) {
     request.open('GET', url);
   } else {
     request.open('GET', '${_manager.baseURL}/$url');
   }
   request.responseType = 'arraybuffer';
   request.onLoad.listen((e) => _onRequestSuccess(request, completer));
   request.onError.listen((e) => _onRequestError(request, completer));
   request.onAbort.listen((e) => _onRequestError(request, completer));
   request.send();
   return completer.future;
 }

 /** Make an empty clip buffer with [numberOfSampleFrames] in
  * each [numberOfChannels]. The buffer plays at a rate of [sampleRate].
  * The duration (in seconds) of the buffer is equal to:
  * numberOfSampleFrames / sampleRate
  */
 void makeBuffer(num numberOfSampleFrames, num numberOfChannels, num sampleRate) {
   _buffer = _manager._context.createBuffer(numberOfChannels,
                                            numberOfChannels,
                                            sampleRate);
   _isReadyToPlay = true;
 }

 /** Return the sample frames array for [channel]. Assuming a stereo setup,
  * the left and right speakers are mapped to channel 0 and 1 respectively. */
 Float32List getSampleFramesForChannel(num channel) {
   if (_buffer == null) {
     return null;
   }
   return _buffer.getChannelData(channel);
 }

 /** Number of clip channels. */
 num get numberOfChannels {
   if (_buffer == null) {
     return 0;
   }
   return _buffer.numberOfChannels;
 }

 /** Length of clip in seconds. */
 num get length {
   if (_buffer == null) {
     return 0;
   }
   return _buffer.duration;
 }

 /** Length of clip in samples. */
 num get samples {
   if (_buffer == null) {
     return 0;
   }
   return _buffer.length;
 }

 /** Samples per second. */
 num get frequency {
   if (_buffer == null) {
     return 0;
   }
   return _buffer.sampleRate;
 }

 /** Is the clip ready to be played? */
 bool get isReadyToPlay => _isReadyToPlay;
}