/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
var Guacamole = Guacamole || {};
/**
* Maintains a singleton instance of the Web Audio API AudioContext class,
* instantiating the AudioContext only in response to the first call to
* getAudioContext(), and only if no existing AudioContext instance has been
* provided via the singleton property. Subsequent calls to getAudioContext()
* will return the same instance.
*
* @namespace
*/
Guacamole.AudioContextFactory = {
/**
* A singleton instance of a Web Audio API AudioContext object, or null if
* no instance has yes been created. This property may be manually set if
* you wish to supply your own AudioContext instance, but care must be
* taken to do so as early as possible. Assignments to this property will
* not retroactively affect the value returned by previous calls to
* getAudioContext().
*
* @type {AudioContext}
*/
'singleton' : null,
/**
* Returns a singleton instance of a Web Audio API AudioContext object.
*
* @return {AudioContext}
* A singleton instance of a Web Audio API AudioContext object, or null
* if the Web Audio API is not supported.
*/
'getAudioContext' : function getAudioContext() {
// Fallback to Webkit-specific AudioContext implementation
var AudioContext = window.AudioContext || window.webkitAudioContext;
// Get new AudioContext instance if Web Audio API is supported
if (AudioContext) {
try {
// Create new instance if none yet exists
if (!Guacamole.AudioContextFactory.singleton)
Guacamole.AudioContextFactory.singleton = new AudioContext();
// Return singleton instance
return Guacamole.AudioContextFactory.singleton;
}
catch (e) {
// Do not use Web Audio API if not allowed by browser
}
}
// Web Audio API not supported
return null;
}
};