phaser/src/sound/BaseSoundManager.js

var Class = require('../utils/Class');
var EventEmitter = require('eventemitter3');
var NOOP = require('../utils/NOOP');

/**
 * @classdesc
 * The sound manager is responsible for playing back audio via Web Audio API or HTML Audio tag as fallback.
 * The audio file type and the encoding of those files are extremely important.
 * Not all browsers can play all audio formats.
 * There is a good guide to what's supported [here](https://developer.mozilla.org/en-US/Apps/Fundamentals/Audio_and_video_delivery/Cross-browser_audio_basics#Audio_Codec_Support).
 *
 * @class BaseSoundManager
 * @extends Phaser.Sound.EventEmitter
 * @memberOf Phaser.Sound
 * @constructor
 * @author Pavle Goloskokovic <pgoloskokovic@gmail.com> (http://prunegames.com)
 * @since 3.0.0
 *
 * @param {Phaser.Game} game - Reference to the current game instance.
 */
var BaseSoundManager = new Class({

    Extends: EventEmitter,

    initialize:

    function BaseSoundManager (game)
    {
        EventEmitter.call(this);

        /**
         * Local reference to game.
         *
         * @name Phaser.Sound.BaseSoundManager#game
         * @type {Phaser.Game}
         * @readOnly
         * @since 3.0.0
         */
        this.game = game;

        /**
         * An array containing all added sounds.
         *
         * @name Phaser.Sound.BaseSoundManager#sounds
         * @type {array}
         * @default []
         * @private
         * @since 3.0.0
         */
        this.sounds = [];

        /**
         * Global mute setting.
         *
         * @name Phaser.Sound.BaseSoundManager#mute
         * @type {boolean}
         * @default false
         * @since 3.0.0
         */
        this.mute = false;

        /**
         * Global volume setting.
         *
         * @name Phaser.Sound.BaseSoundManager#volume
         * @type {number}
         * @default 1
         * @since 3.0.0
         */
        this.volume = 1;

        /**
         * Global playback rate at which all the sounds will be played.
         * Value of 1.0 plays the audio at full speed, 0.5 plays the audio at half speed
         * and 2.0 doubles the audio's playback speed.
         *
         * @name Phaser.Sound.BaseSoundManager#rate
         * @type {number}
         * @default 1
         * @since 3.0.0
         */
        this.rate = 1;

        /**
         * Global detuning of all sounds in [cents](https://en.wikipedia.org/wiki/Cent_%28music%29).
         * The range of the value is -1200 to 1200, but we recommend setting it to [50](https://en.wikipedia.org/wiki/50_Cent).
         *
         * @name Phaser.Sound.BaseSoundManager#detune
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.detune = 0;

        /**
         * Flag indicating if sounds should be paused when game looses focus,
         * for instance when user switches to another tab/program/app.
         *
         * @name Phaser.Sound.BaseSoundManager#pauseOnBlur
         * @type {boolean}
         * @default true
         * @since 3.0.0
         */
        this.pauseOnBlur = true;

        game.events.on('blur', function ()
        {
            if (this.pauseOnBlur)
            {
                this.onBlur();
            }
        }, this);

        game.events.on('focus', function ()
        {
            if (this.pauseOnBlur)
            {
                this.onFocus();
            }
        }, this);

        game.events.once('destroy', this.destroy, this);

        /**
         * Property that actually holds the value of global playback rate.
         *
         * @name Phaser.Sound.BaseSoundManager#_rate
         * @type {number}
         * @private
         * @default 1
         * @since 3.0.0
         */
        this._rate = 1;

        /**
         * Property that actually holds the value of global detune.
         *
         * @name Phaser.Sound.BaseSoundManager#_detune
         * @type {number}
         * @private
         * @default 0
         * @since 3.0.0
         */
        this._detune = 0;

        /**
         * Mobile devices require sounds to be triggered from an explicit user action,
         * such as a tap, before any sound can be loaded/played on a web page.
         * Set to true if the audio system is currently locked awaiting user interaction.
         *
         * @name Phaser.Sound.BaseSoundManager#locked
         * @type {boolean}
         * @since 3.0.0
         */
        this.locked = this.locked || false;

        /**
         * Flag used internally for handling when the audio system
         * has been unlocked, if there ever was a need for it.
         *
         * @name Phaser.Sound.BaseSoundManager#unlocked
         * @type {boolean}
         * @default false
         * @since 3.0.0
         */
        this.unlocked = false;

        if (this.locked)
        {
            this.unlock();
        }
    },

    /**
     * Adds a new sound into the sound manager.
     *
     * @method Phaser.Sound.BaseSoundManager#add
     * @override
     * @since 3.0.0
     * 
     * @param {string} key - Asset key for the sound.
     * @param {ISoundConfig} [config] - An optional config object containing default sound settings.
     * 
     * @return {ISound} The new sound instance.
     */
    add: NOOP,

    /**
     * Adds a new audio sprite sound into the sound manager.
     *
     * @method Phaser.Sound.BaseSoundManager#addAudioSprite
     * @since 3.0.0
     * 
     * @param {string} key - Asset key for the sound.
     * @param {ISoundConfig} [config] - An optional config object containing default sound settings.
     * 
     * @return {IAudioSpriteSound} The new audio sprite sound instance.
     */
    addAudioSprite: function (key, config)
    {
        var sound = this.add(key, config);

        /**
         * Local reference to 'spritemap' object form json file generated by audiosprite tool.
         *
         * @property {object} spritemap
         */
        sound.spritemap = this.game.cache.json.get(key).spritemap;

        for (var markerName in sound.spritemap)
        {
            if (!sound.spritemap.hasOwnProperty(markerName))
            {
                continue;
            }

            var marker = sound.spritemap[markerName];

            sound.addMarker({
                name: markerName,
                start: marker.start,
                duration: marker.end - marker.start,
                config: config
            });
        }

        return sound;
    },

    /**
     * Enables playing sound on the fly without the need to keep a reference to it.
     * Sound will auto destroy once its playback ends.
     *
     * @method Phaser.Sound.BaseSoundManager#play
     * @since 3.0.0
     * 
     * @param {string} key - Asset key for the sound.
     * @param {ISoundConfig | ISoundMarker} [extra] - An optional additional object containing settings to be applied to the sound. It could be either config or marker object.
     * 
     * @return {boolean} Whether the sound started playing successfully.
     */
    play: function (key, extra)
    {
        var sound = this.add(key);

        sound.once('ended', sound.destroy, sound);

        if (extra)
        {
            if (extra.name)
            {
                sound.addMarker(extra);
                return sound.play(extra.name);
            }
            else
            {
                return sound.play(extra);
            }
        }
        else
        {
            return sound.play();
        }
    },

    /**
     * Enables playing audio sprite sound on the fly without the need to keep a reference to it.
     * Sound will auto destroy once its playback ends.
     *
     * @method Phaser.Sound.BaseSoundManager#playAudioSprite
     * @since 3.0.0
     * 
     * @param {string} key - Asset key for the sound.
     * @param {string} spriteName - The name of the sound sprite to play.
     * @param {ISoundConfig} [config] - An optional config object containing default sound settings.
     * 
     * @return {boolean} Whether the audio sprite sound started playing successfully.
     */
    playAudioSprite: function (key, spriteName, config)
    {
        var sound = this.addAudioSprite(key);

        sound.once('ended', sound.destroy, sound);

        return sound.play(spriteName, config);
    },

    /**
     * Removes a sound from the sound manager.
     * The removed sound is destroyed before removal.
     *
     * @method Phaser.Sound.BaseSoundManager#remove
     * @since 3.0.0
     * 
     * @param {ISound} sound - The sound object to remove.
     * 
     * @return {boolean} True if the sound was removed successfully, otherwise false.
     */
    remove: function (sound)
    {
        var index = this.sounds.indexOf(sound);
        if (index !== -1)
        {
            sound.destroy();
            this.sounds.splice(index, 1);
            return true;
        }
        return false;
    },

    /**
     * Removes all sounds from the sound manager that have an asset key matching the given value.
     * The removed sounds are destroyed before removal.
     *
     * @method Phaser.Sound.BaseSoundManager#removeByKey
     * @since 3.0.0
     * 
     * @param {string} key - The key to match when removing sound objects.
     * 
     * @return {number} The number of matching sound objects that were removed.
     */
    removeByKey: function (key)
    {
        var removed = 0;
        for (var i = this.sounds.length - 1; i >= 0; i--)
        {
            var sound = this.sounds[i];
            if (sound.key === key)
            {
                sound.destroy();
                this.sounds.splice(i, 1);
                removed++;
            }
        }
        return removed;
    },

    /**
     * Pauses all the sounds in the game.
     *
     * @method Phaser.Sound.BaseSoundManager#pauseAll
     * @since 3.0.0
     */
    pauseAll: function ()
    {
        this.forEachActiveSound(function (sound)
        {
            sound.pause();
        });

        /**
         * @event Phaser.Sound.BaseSoundManager#pauseall
         * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
         */
        this.emit('pauseall', this);
    },

    /**
     * Resumes all the sounds in the game.
     *
     * @method Phaser.Sound.BaseSoundManager#resumeAll
     * @since 3.0.0
     */
    resumeAll: function ()
    {
        this.forEachActiveSound(function (sound)
        {
            sound.resume();
        });

        /**
         * @event Phaser.Sound.BaseSoundManager#resumeall
         * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
         */
        this.emit('resumeall', this);
    },

    /**
     * Stops all the sounds in the game.
     *
     * @method Phaser.Sound.BaseSoundManager#stopAll
     * @since 3.0.0
     */
    stopAll: function ()
    {
        this.forEachActiveSound(function (sound)
        {
            sound.stop();
        });

        /**
         * @event Phaser.Sound.BaseSoundManager#stopall
         * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
         */
        this.emit('stopall', this);
    },

    /**
     * Method used internally for unlocking audio playback on devices that
     * require user interaction before any sound can be played on a web page.
     *
     * Read more about how this issue is handled here in [this article](https://medium.com/@pgoloskokovic/unlocking-web-audio-the-smarter-way-8858218c0e09).
     *
     * @method Phaser.Sound.BaseSoundManager#unlock
     * @override
     * @protected
     * @since 3.0.0
     */
    unlock: NOOP,

    /**
     * Method used internally for pausing sound manager if
     * Phaser.Sound.BaseSoundManager#pauseOnBlur is set to true.
     *
     * @method Phaser.Sound.BaseSoundManager#onBlur
     * @override
     * @protected
     * @since 3.0.0
     */
    onBlur: NOOP,

    /**
     * Method used internally for resuming sound manager if
     * Phaser.Sound.BaseSoundManager#pauseOnBlur is set to true.
     *
     * @method Phaser.Sound.BaseSoundManager#onFocus
     * @override
     * @protected
     * @since 3.0.0
     */
    onFocus: NOOP,

    /**
     * Update method called on every game step.
     * Removes destroyed sounds and updates every active sound in the game.
     *
     * @method Phaser.Sound.BaseSoundManager#update
     * @protected
     * @since 3.0.0
     * 
     * @param {number} time - The current timestamp as generated by the Request Animation Frame or SetTimeout.
     * @param {number} delta - The delta time elapsed since the last frame.
     */
    update: function (time, delta)
    {
        if (this.unlocked)
        {
            this.unlocked = false;
            this.locked = false;

            /**
             * @event Phaser.Sound.BaseSoundManager#unlocked
             * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
             */
            this.emit('unlocked', this);
        }

        for (var i = this.sounds.length - 1; i >= 0; i--)
        {
            if (this.sounds[i].pendingRemove)
            {
                this.sounds.splice(i, 1);
            }
        }

        this.sounds.forEach(function (sound)
        {
            sound.update(time, delta);
        });
    },

    /**
     * Destroys all the sounds in the game and all associated events.
     *
     * @method Phaser.Sound.BaseSoundManager#destroy
     * @since 3.0.0
     */
    destroy: function ()
    {
        this.removeAllListeners();

        this.forEachActiveSound(function (sound)
        {
            sound.destroy();
        });

        this.sounds.length = 0;
        this.sounds = null;
        this.game = null;
    },

    /**
     * Method used internally for iterating only over active sounds and skipping sounds that are marked for removal.
     *
     * @method Phaser.Sound.BaseSoundManager#forEachActiveSound
     * @private
     * @since 3.0.0
     * 
     * @param {function} callbackfn - Callback function. (sound: ISound, index: number, array: ISound[]) => void
     * @param [scope] - Callback context.
     */
    forEachActiveSound: function (callbackfn, scope)
    {
        var _this = this;

        this.sounds.forEach(function (sound, index)
        {
            if (!sound.pendingRemove)
            {
                callbackfn.call(scope || _this, sound, index, _this.sounds);
            }
        });
    }

});

/**
 * Global playback rate.
 *
 * @name Phaser.Sound.BaseSoundManager#rate
 * @type {number}
 * @since 3.0.0
 */
Object.defineProperty(BaseSoundManager.prototype, 'rate', {

    get: function ()
    {
        return this._rate;
    },

    set: function (value)
    {
        this._rate = value;
        this.forEachActiveSound(function (sound)
        {
            sound.setRate();
        });

        /**
         * @event Phaser.Sound.BaseSoundManager#rate
         * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
         * @param {number} value - An updated value of Phaser.Sound.BaseSoundManager#rate property.
         */
        this.emit('rate', this, value);
    }

});

/**
 * Global detune.
 *
 * @name Phaser.Sound.BaseSoundManager#detune
 * @type {number}
 * @since 3.0.0
 */
Object.defineProperty(BaseSoundManager.prototype, 'detune', {

    get: function ()
    {
        return this._detune;
    },

    set: function (value)
    {
        this._detune = value;
        this.forEachActiveSound(function (sound)
        {
            sound.setRate();
        });

        /**
         * @event Phaser.Sound.BaseSoundManager#detune
         * @param {Phaser.Sound.BaseSoundManager} soundManager - Reference to the sound manager that emitted event.
         * @param {number} value - An updated value of Phaser.Sound.BaseSoundManager#detune property.
         */
        this.emit('detune', this, value);
    }

});

module.exports = BaseSoundManager;