source: trunk/web/addons/job_monarch/lib/extjs/air/src/MusicPlayer.js @ 619

/*
 * Ext JS Library 0.30
 * Copyright(c) 2006-2009, Ext JS, LLC.
 * licensing@extjs.com
 * 
 * http://extjs.com/license
 */

Ext.ns('Ext.air');

Ext.air.MusicPlayer = Ext.extend(Ext.util.Observable, {
        /**
         * The currently active Sound. Read-only.
         * @type air.Sound
         * @property activeSound
         */
        activeSound: null,
        /**
         * The currently active SoundChannel. Read-only.
         * @type air.SoundChannel
         * @property activeChannel
         */
        activeChannel: null,
        /**
         * The currently active Transform. Read-only.
         * @type air.SoundTransform
         * @property activeTransform
         */
        activeTransform: new air.SoundTransform(1, 0),
        // private 
        pausePosition: 0,
        /**
         * @cfg {Number} progressInterval
         * How often to fire the progress event when playing music in milliseconds
         * Defaults to 500.
         */
        progressInterval: 500,
        
        constructor: function(config) {
                config = config || {};
                Ext.apply(this, config);
                
                this.addEvents(
                        /**
                         * @event stop
                         */
                        'stop',
                        /**
                         * @event pause
                         */
                        'pause',
                        /**
                         * @event play
                         */
                        'play',
                        /**
                         * @event load
                         */
                        'load',
                        /**
                         * @event id3info
                         */
                        'id3info',
                        /**
                         * @event complete
                         */
                        'complete',
                        /**
                         * @event progress
                         */
                        'progress',
                        /**
                         * @event skip
                         */
                        'skip'
                );
                
                Ext.air.MusicPlayer.superclass.constructor.call(this, config);
                this.onSoundFinishedDelegate = this.onSoundFinished.createDelegate(this);
                this.onSoundLoadDelegate = this.onSoundLoad.createDelegate(this);
                this.onSoundID3LoadDelegate = this.onSoundID3Load.createDelegate(this);

                Ext.TaskMgr.start({
                        run: this.notifyProgress,
                        scope: this,
                        interval: this.progressInterval
                });             
        },      

        /**
         * Adjust the volume
         * @param {Object} percent
         * Ranges from 0 to 1 specifying volume of sound.
         */
        adjustVolume: function(percent) {
                this.activeTransform.volume = percent;
                if (this.activeChannel) {               
                        this.activeChannel.soundTransform = this.activeTransform;               
                }               
        },
        /**
         * Stop the player
         */
        stop: function() {
                this.pausePosition = 0;         
                if (this.activeChannel) {
                        this.activeChannel.stop();                      
                        this.activeChannel = null;                      
                }               
                if (this.activeSound) {
                        this.activeSound.removeEventListener(air.Event.COMPLETE, this.onSoundLoadDelegate);
                        this.activeSound.removeEventListener(air.Event.ID3, this.onSoundID3LoadDelegate);
                        this.activeSound.removeEventListener(air.Event.SOUND_COMPLETE, this.onSoundFinishedDelegate);                                           
                }
        },
        /**
         * Pause the player if there is an activeChannel
         */
        pause: function() {
                if (this.activeChannel) {
                        this.pausePosition = this.activeChannel.position;
                        this.activeChannel.stop();                      
                }               
        },
        /**
         * Play a sound, if no url is specified will attempt to resume the activeSound
         * @param {String} url (optional)
         * Url resource to play
         */
        play: function(url) {
                if (url) {                      
                        this.stop();                    
                        var req = new air.URLRequest(url);
                        this.activeSound = new air.Sound();
                        this.activeSound.addEventListener(air.Event.SOUND_COMPLETE, this.onSoundFinishedDelegate);                                              
                        this.activeSound.addEventListener(air.Event.COMPLETE, this.onSoundLoadDelegate);                        
                        this.activeSound.addEventListener(air.Event.ID3, this.onSoundID3LoadDelegate);
                        this.activeSound.load(req);                                             
                } else {
                        this.onSoundLoad();     
                }       
        },
        
        /**
         * Skip to a specific position in the song currently playing.
         * @param {Object} pos
         */
        skipTo: function(pos) {
                if (this.activeChannel) {
                        this.activeChannel.stop();              
                        this.activeChannel = this.activeSound.play(pos);        
                        this.activeChannel.soundTransform = this.activeTransform;               
                        this.fireEvent('skip', this.activeChannel, this.activeSound, pos);
                }
        },
        
        /**
         * Returns whether or not there is an active SoundChannel.
         */
        hasActiveChannel: function() {
                return !!this.activeChannel;
        },
        
        // private
        onSoundLoad: function(event) {
                if (this.activeSound) {
                        if (this.activeChannel) {
                                this.activeChannel.stop();
                        }
                        this.activeChannel = this.activeSound.play(this.pausePosition);
                        this.activeChannel.soundTransform = this.activeTransform;
                        this.fireEvent('load', this.activeChannel, this.activeSound);
                }               
        },
        // private
        onSoundFinished: function(event) {
                // relay AIR event
                this.fireEvent('complete', event);
        },
        // private
        onSoundID3Load: function(event) {
                this.activeSound.removeEventListener(air.Event.ID3, this.onSoundID3LoadDelegate);               
                var id3 = event.target.id3;             
                this.fireEvent('id3info', id3);
        },
        // private
        notifyProgress: function() {
                if (this.activeChannel && this.activeSound) {
                        var playbackPercent = 100 * (this.activeChannel.position / this.activeSound.length);                    
                        // SOUND_COMPLETE does not seem to work consistently.
                        if (playbackPercent > 99.7) {
                                this.onSoundFinished();                         
                        } else {
                                this.fireEvent('progress', this.activeChannel, this.activeSound);
                        }       
                }               
        }               
});