| /* |
| * Buffer Loader Object |
| * This class provides a sound buffer for one or more sounds |
| * holded in a local file located by an url |
| * |
| * uses W3C Web Audio API |
| * |
| * @constructor |
| * |
| * @param {AudioContext} audio context object |
| * @param {Array} urlList, array of url for sound to load |
| * @param {function} callback , called after buffer was loaded |
| * |
| */ |
| |
| function BufferLoader(context, urlList, callback) { |
| this.context = context; |
| this.urlList = urlList; |
| this.onload = callback; |
| this.bufferList = []; |
| this.loadCount = 0; |
| } |
| |
| /* |
| * This method loads a sound into a buffer |
| * @param {Array} urlList, array of url for sound to load |
| * @param {Number} index, buffer index in the array where to load the url sound |
| * |
| */ |
| |
| BufferLoader.prototype.loadBuffer = function(url, index) { |
| // Load buffer asynchronously |
| var request = null, |
| loader = null; |
| |
| request = new XMLHttpRequest(); |
| |
| if (request === null) { |
| console.log ("BufferLoader.prototype.loadBuffer, cannot allocate XML http request"); |
| return; |
| } |
| |
| request.open("GET", url, true); |
| request.responseType = "arraybuffer"; |
| |
| loader = this; |
| |
| request.onload = function() { |
| // Asynchronously decode the audio file data in request.response |
| loader.context.decodeAudioData( |
| request.response, |
| function(buffer) { |
| if (!buffer) { |
| console.log ("BufferLoader.prototype.loadBuffer,error decoding file data: " + url); |
| return; |
| } |
| |
| loader.bufferList[index] = buffer; |
| |
| if (++loader.loadCount == loader.urlList.length) { |
| loader.onload(loader.bufferList); |
| } |
| } |
| ); |
| }; |
| |
| request.onerror = function() { |
| console.log ("BufferLoader.prototype.loadBuffer, XHR error"); |
| }; |
| |
| request.send(); |
| }; |
| |
| /* |
| * This method loads all sounds identified by their url |
| * and that where given to the object constructor |
| * |
| */ |
| |
| BufferLoader.prototype.load = function() { |
| for (var i = 0; i < this.urlList.length; ++i) { |
| this.loadBuffer(this.urlList[i], i); |
| } |
| }; |
| |
| module.exports = BufferLoader; |