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howler.js
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howler.js
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/*!
* howler.js v2.0.0-beta
* howlerjs.com
*
* (c) 2013-2015, James Simpson of GoldFire Studios
* goldfirestudios.com
*
* MIT License
*/
(function () {
'use strict';
// Setup our audio context.
var ctx = null;
var usingWebAudio = true;
var noAudio = false;
setupAudioContext();
// Create a master gain node.
if (usingWebAudio) {
var masterGain = (typeof ctx.createGain === 'undefined') ? ctx.createGainNode() : ctx.createGain();
masterGain.gain.value = 1;
masterGain.connect(ctx.destination);
}
/** Global Methods **/
/***************************************************************************/
/**
* Create the global controller. All contained methods and properties apply
* to all sounds that are currently playing or will be in the future.
*/
var HowlerGlobal = function () {
this.init();
};
HowlerGlobal.prototype = {
/**
* Initialize the global Howler object.
* @return {Howler}
*/
init: function () {
var self = this || Howler;
// Internal properties.
self._codecs = {};
self._howls = [];
self._muted = false;
self._volume = 1;
// Set to false to disable the auto iOS enabler.
self.iOSAutoEnable = true;
// No audio is available on this system if this is set to true.
self.noAudio = noAudio;
// This will be true if the Web Audio API is available.
self.usingWebAudio = usingWebAudio;
// Expose the AudioContext when using Web Audio.
self.ctx = ctx;
// Check for supported codecs.
if (!noAudio) {
self._setupCodecs();
}
return self;
},
/**
* Get/set the global volume for all sounds.
* @param {Float} vol Volume from 0.0 to 1.0.
* @return {Howler/Float} Returns self or current volume.
*/
volume: function (vol) {
var self = this || Howler;
vol = parseFloat(vol);
if (typeof vol !== 'undefined' && vol >= 0 && vol <= 1) {
self._volume = vol;
// When using Web Audio, we just need to adjust the master gain.
if (usingWebAudio) {
masterGain.gain.value = vol;
}
// Loop through and change volume for all HTML5 audio nodes.
for (var i = 0; i < self._howls.length; i++) {
if (!self._howls[i]._webAudio) {
// Get all of the sounds in this Howl group.
var ids = self._howls[i]._getSoundIds();
// Loop through all sounds and change the volumes.
for (var j = 0; j < ids.length; j++) {
var sound = self._howls[i]._soundById(ids[j]);
if (sound && sound._node) {
sound._node.volume = sound._volume * vol;
}
}
}
}
return self;
}
return self._volume;
},
/**
* Handle muting and unmuting globally.
* @param {Boolean} muted Is muted or not.
*/
mute: function (muted) {
var self = this || Howler;
self._muted = muted;
// With Web Audio, we just need to mute the master gain.
if (usingWebAudio) {
masterGain.gain.value = muted ? 0 : self._volume;
}
// Loop through and mute all HTML5 Audio nodes.
for (var i = 0; i < self._howls.length; i++) {
if (!self._howls[i]._webAudio) {
// Get all of the sounds in this Howl group.
var ids = self._howls[i]._getSoundIds();
// Loop through all sounds and mark the audio node as muted.
for (var j = 0; j < ids.length; j++) {
var sound = self._howls[i]._soundById(ids[j]);
if (sound && sound._node) {
sound._node.muted = (muted) ? true : sound._muted;
}
}
}
}
return self;
},
/**
* Check for codec support of specific extension.
* @param {String} ext Audio file extention.
* @return {Boolean}
*/
codecs: function (ext) {
return (this || Howler)._codecs[ext];
},
/**
* Check for browser support for various codecs and cache the results.
* @return {Howler}
*/
_setupCodecs: function () {
var self = this || Howler;
var audioTest = new Audio();
var mpegTest = audioTest.canPlayType('audio/mpeg;').replace(/^no$/, '');
self._codecs = {
mp3: !!(mpegTest || audioTest.canPlayType('audio/mp3;').replace(/^no$/, '')),
mpeg: !!mpegTest,
opus: !!audioTest.canPlayType('audio/ogg; codecs="opus"').replace(/^no$/, ''),
ogg: !!audioTest.canPlayType('audio/ogg; codecs="vorbis"').replace(/^no$/, ''),
wav: !!audioTest.canPlayType('audio/wav; codecs="1"').replace(/^no$/, ''),
aac: !!audioTest.canPlayType('audio/aac;').replace(/^no$/, ''),
m4a: !!(audioTest.canPlayType('audio/x-m4a;') || audioTest.canPlayType('audio/m4a;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
mp4: !!(audioTest.canPlayType('audio/x-mp4;') || audioTest.canPlayType('audio/mp4;') || audioTest.canPlayType('audio/aac;')).replace(/^no$/, ''),
weba: !!audioTest.canPlayType('audio/webm; codecs="vorbis"').replace(/^no$/, ''),
webm: !!audioTest.canPlayType('audio/webm; codecs="vorbis"').replace(/^no$/, '')
};
return self;
},
/**
* iOS will only allow audio to be played after a user interaction.
* Attempt to automatically unlock audio on the first user interaction.
* Concept from: http:https://paulbakaus.com/tutorials/html5/web-audio-on-ios/
* @return {Howler}
*/
_enableiOSAudio: function () {
var self = this || Howler;
// Only run this on iOS if audio isn't already eanbled.
if (ctx && (self._iOSEnabled || !/iPhone|iPad|iPod/i.test(navigator.userAgent))) {
return;
}
self._iOSEnabled = false;
// Call this method on touch start to create and play a buffer,
// then check if the audio actually played to determine if
// audio has now been unlocked on iOS.
var unlock = function () {
// Create an empty buffer.
var buffer = ctx.createBuffer(1, 1, 22050);
var source = ctx.createBufferSource();
source.buffer = buffer;
source.connect(ctx.destination);
// Play the empty buffer.
if (typeof source.start === 'undefined') {
source.noteOn(0);
} else {
source.start(0);
}
// Setup a timeout to check that we are unlocked on the next event loop.
setTimeout(function () {
if ((source.playbackState === source.PLAYING_STATE || source.playbackState === source.FINISHED_STATE)) {
// Update the unlocked state and prevent this check from happening again.
self._iOSEnabled = true;
self.iOSAutoEnable = false;
// Remove the touch start listener.
document.removeEventListener('touchstart', unlock, false);
}
}, 0);
};
// Setup a touch start listener to attempt an unlock in.
document.addEventListener('touchstart', unlock, false);
return self;
}
};
// Setup the global audio controller.
var Howler = new HowlerGlobal();
/** Group Methods **/
/***************************************************************************/
/**
* Create an audio group controller.
* @param {Object} o Passed in properties for this group.
*/
var Howl = function (o) {
var self = this;
// Throw an error if no source is provided.
if (!o.src || o.src.length === 0) {
console.error('An array of source files must be passed with any new Howl.');
return;
}
self.init(o);
};
Howl.prototype = {
/**
* Initialize a new Howl group object.
* @param {Object} o Passed in properties for this group.
* @return {Howl}
*/
init: function (o) {
var self = this;
// Setup user-defined default properties.
self._autoplay = o.autoplay || false;
self._ext = o.ext || null;
self._html5 = o.html5 || false;
self._muted = o.mute || false;
self._loop = o.loop || false;
self._pool = o.pool || 5;
self._preload = (typeof o.preload === 'boolean') ? o.preload : true;
self._rate = o.rate || 1;
self._sprite = o.sprite || {};
self._src = (typeof o.src !== 'string') ? o.src : [o.src];
self._volume = o.volume !== undefined ? o.volume : 1;
// Setup all other default properties.
self._duration = 0;
self._loaded = false;
self._sounds = [];
self._endTimers = {};
// Setup event listeners.
self._onend = o.onend ? [{fn: o.onend}] : [];
self._onfaded = o.onfaded ? [{fn: o.onfaded}] : [];
self._onload = o.onload ? [{fn: o.onload}] : [];
self._onloaderror = o.onloaderror ? [{fn: o.onloaderror}] : [];
self._onpause = o.onpause ? [{fn: o.onpause}] : [];
self._onplay = o.onplay ? [{fn: o.onplay}] : [];
// Web Audio or HTML5 Audio?
self._webAudio = usingWebAudio && !self._html5;
// Automatically try to enable audio on iOS.
if (typeof ctx !== 'undefined' && ctx && Howler.iOSAutoEnable) {
Howler._enableiOSAudio();
}
// Keep track of this Howl group in the global controller.
Howler._howls.push(self);
// Load the source file unless otherwise specified.
if (self._preload) {
self.load();
}
return self;
},
/**
* Load the audio file.
* @return {Howler}
*/
load: function () {
var self = this;
var url = null;
// If no audio is available, quit immediately.
if (noAudio) {
self._emit('loaderror');
return;
}
// Make sure our source is in an array.
if (typeof self._src === 'string') {
self._src = [self._src];
}
// Loop through the sources and pick the first one that is compatible.
for (var i = 0; i < self._src.length; i++) {
var ext, str;
if (self._ext && self._ext[i]) {
// If an extension was specified, use that instead.
ext = self._ext[i];
} else {
// Extract the file extension from the URL or base64 data URI.
str = self._src[i];
ext = /^data:audio\/([^;,]+);/i.exec(str);
if (!ext) {
ext = /\.([^.]+)$/.exec(str.split('?', 1)[0]);
}
if (ext) {
ext = ext[1].toLowerCase();
}
}
// Check if this extension is available.
if (Howler.codecs(ext)) {
url = self._src[i];
break;
}
}
if (!url) {
self._emit('loaderror');
return;
}
self._src = url;
// Create a new sound object and add it to the pool.
new Sound(self);
// Load and decode the audio data for playback.
if (self._webAudio) {
loadBuffer(self);
}
return self;
},
/**
* Play a sound or resume previous playback.
* @param {String/Number} sprite Sprite name for sprite playback or sound id to continue previous.
* @return {Number} Sound ID.
*/
play: function (sprite) {
var self = this;
var args = arguments;
var id = null;
// Determine if a sprite, sound id or nothing was passed
if (typeof sprite === 'number') {
id = sprite;
sprite = null;
} else if (typeof sprite === 'undefined') {
// Use the default sound sprite (plays the full audio length).
sprite = '__default';
// Check if there is a single paused sound that isn't ended.
// If there is, play that sound. If not, continue as usual.
var num = 0;
for (var i = 0; i < self._sounds.length; i++) {
if (self._sounds[i]._paused && !self._sounds[i]._ended) {
num++;
id = self._sounds[i]._id;
}
}
if (num === 1) {
sprite = null;
} else {
id = null;
}
}
// Get the selected node, or get one from the pool.
var sound = id ? self._soundById(id) : self._inactiveSound();
// If the sound doesn't exist, do nothing.
if (!sound) {
return null;
}
// Select the sprite definition.
if (id && !sprite) {
sprite = sound._sprite || '__default';
}
// If we have no sprite and the sound hasn't loaded, we must wait
// for the sound to load to get our audio's duration.
if (!self._loaded && !self._sprite[sprite]) {
self.once('load', function () {
self.play(self._soundById(sound._id) ? sound._id : undefined);
});
return sound._id;
}
// Don't play the sound if an id was passed and it is already playing.
if (id && !sound._paused) {
return sound._id;
}
// Determine how long to play for and where to start playing.
var seek = sound._seek > 0 ? sound._seek : self._sprite[sprite][0] / 1000;
var duration = ((self._sprite[sprite][0] + self._sprite[sprite][1]) / 1000) - seek;
// Create a timer to fire at the end of playback or the start of a new loop.
var ended = function () {
// Should this sound loop?
var loop = !!(sound._loop || self._sprite[sprite][2]);
// Fire the ended event.
self._emit('end', sound._id);
// Restart the playback for HTML5 Audio loop.
if (!self._webAudio && loop) {
self.stop(sound._id).play(sound._id);
}
// Restart this timer if on a Web Audio loop.
if (self._webAudio && loop) {
self._emit('play', sound._id);
sound._seek = sound._start || 0;
sound._playStart = ctx.currentTime;
self._endTimers[sound._id] = setTimeout(ended, ((sound._stop - sound._start) * 1000) / Math.abs(self._rate));
}
// Mark the node as paused.
if (self._webAudio && !loop) {
sound._paused = true;
sound._ended = true;
sound._seek = sound._start || 0;
self._clearTimer(sound._id);
// Clean up the buffer source.
sound._node.bufferSource = null;
}
// When using a sprite, end the track.
if (!self._webAudio && !loop) {
self.stop(sound._id);
}
};
self._endTimers[sound._id] = setTimeout(ended, (duration * 1000) / Math.abs(self._rate));
// Update the parameters of the sound
sound._paused = false;
sound._ended = false;
sound._sprite = sprite;
sound._seek = seek;
sound._start = self._sprite[sprite][0] / 1000;
sound._stop = (self._sprite[sprite][0] + self._sprite[sprite][1]) / 1000;
sound._loop = !!(sound._loop || self._sprite[sprite][2]);
// Begin the actual playback.
var node = sound._node;
if (self._webAudio) {
// Fire this when the sound is ready to play to begin Web Audio playback.
var playWebAudio = function () {
self._refreshBuffer(sound);
// Setup the playback params.
var vol = (sound._muted || self._muted) ? 0 : sound._volume * Howler.volume();
node.gain.setValueAtTime(vol, ctx.currentTime);
sound._playStart = ctx.currentTime;
// Play the sound using the supported method.
if (typeof node.bufferSource.start === 'undefined') {
sound._loop ? node.bufferSource.noteGrainOn(0, seek, 86400) : node.bufferSource.noteGrainOn(0, seek, duration);
} else {
sound._loop ? node.bufferSource.start(0, seek, 86400) : node.bufferSource.start(0, seek, duration);
}
// Start a new timer if none is present.
if (!self._endTimers[sound._id]) {
self._endTimers[sound._id] = setTimeout(ended, (duration * 1000) / Math.abs(self._rate));
}
if (!args[1]) {
setTimeout(function () {
self._emit('play', sound._id);
}, 0);
}
};
if (self._loaded) {
playWebAudio();
} else {
// Wait for the audio to load and then begin playback.
self.once('load', playWebAudio);
// Cancel the end timer.
self._clearTimer(sound._id);
}
} else {
// Fire this when the sound is ready to play to begin HTML5 Audio playback.
var playHtml5 = function () {
node.currentTime = seek;
node.muted = sound._muted || self._muted || Howler._muted || node.muted;
node.volume = sound._volume * Howler.volume();
node.playbackRate = self._rate;
setTimeout(function () {
node.play();
if (!args[1]) {
self._emit('play', sound._id);
}
}, 0);
};
// Play immediately if ready, or wait for the 'canplaythrough'e vent.
if (node.readyState === 4 || !node.readyState && navigator.isCocoonJS) {
playHtml5();
} else {
var listener = function () {
// Setup the new end timer.
self._endTimers[sound._id] = setTimeout(ended, (duration * 1000) / Math.abs(self._rate));
// Begin playback.
playHtml5();
// Clear this listener.
node.removeEventListener('canplaythrough', listener, false);
};
node.addEventListener('canplaythrough', listener, false);
// Cancel the end timer.
self._clearTimer(sound._id);
}
}
return sound._id;
},
/**
* Pause playback and save current position.
* @param {Number} id The sound ID (empty to pause all in group).
* @return {Howl}
*/
pause: function (id) {
var self = this;
// Wait for the sound to begin playing before pausing it.
if (!self._loaded) {
self.once('play', function () {
self.pause(id);
});
return self;
}
// If no id is passed, get all ID's to be paused.
var ids = self._getSoundIds(id);
for (var i = 0; i < ids.length; i++) {
// Clear the end timer.
self._clearTimer(ids[i]);
// Get the sound.
var sound = self._soundById(ids[i]);
if (sound && !sound._paused) {
// Reset the seek position.
sound._seek = self.seek(ids[i]);
sound._paused = true;
if (self._webAudio) {
// make sure the sound has been created
if (!sound._node.bufferSource) {
return self;
}
if (typeof sound._node.bufferSource.stop === 'undefined') {
sound._node.bufferSource.noteOff(0);
} else {
sound._node.bufferSource.stop(0);
}
// Clean up the buffer source.
sound._node.bufferSource = null;
} else if (!isNaN(sound._node.duration)) {
sound._node.pause();
}
// Fire the pause event, unless `true` is passed as the 2nd argument.
if (!arguments[1]) {
self._emit('pause', sound._id);
}
}
}
return self;
},
/**
* Stop playback and reset to start.
* @param {Number} id The sound ID (empty to stop all in group).
* @return {Howl}
*/
stop: function (id) {
var self = this;
// Wait for the sound to begin playing before stopping it.
if (!self._loaded) {
if (typeof self._sounds[0]._sprite !== 'undefined') {
self.once('play', function () {
self.stop(id);
});
}
return self;
}
// If no id is passed, get all ID's to be stopped.
var ids = self._getSoundIds(id);
for (var i = 0; i < ids.length; i++) {
// Clear the end timer.
self._clearTimer(ids[i]);
// Get the sound.
var sound = self._soundById(ids[i]);
if (sound && !sound._paused) {
// Reset the seek position.
sound._seek = sound._start || 0;
sound._paused = true;
sound._ended = true;
if (self._webAudio && sound._node) {
// make sure the sound has been created
if (!sound._node.bufferSource) {
return self;
}
if (typeof sound._node.bufferSource.stop === 'undefined') {
sound._node.bufferSource.noteOff(0);
} else {
sound._node.bufferSource.stop(0);
}
// Clean up the buffer source.
sound._node.bufferSource = null;
} else if (sound._node && !isNaN(sound._node.duration)) {
sound._node.pause();
sound._node.currentTime = sound._start || 0;
}
}
}
return self;
},
/**
* Mute/unmute a single sound or all sounds in this Howl group.
* @param {Boolean} muted Set to true to mute and false to unmute.
* @param {Number} id The sound ID to update (omit to mute/unmute all).
* @return {Howl}
*/
mute: function (muted, id) {
var self = this;
// Wait for the sound to begin playing before muting it.
if (!self._loaded) {
self.once('play', function () {
self.mute(muted, id);
});
return self;
}
// If applying mute/unmute to all sounds, update the group's value.
if (typeof id === 'undefined') {
if (typeof muted === 'boolean') {
self._muted = muted;
} else {
return self._muted;
}
}
// If no id is passed, get all ID's to be muted.
var ids = self._getSoundIds(id);
for (var i = 0; i < ids.length; i++) {
// Get the sound.
var sound = self._soundById(ids[i]);
if (sound) {
sound._muted = muted;
if (self._webAudio && sound._node) {
sound._node.gain.setValueAtTime(muted ? 0 : sound._volume * Howler.volume(), ctx.currentTime);
} else if (sound._node) {
sound._node.muted = Howler._muted ? true : muted;
}
}
}
return self;
},
/**
* Get/set the volume of this sound or of the Howl group. This method can optionally take 0, 1 or 2 arguments.
* volume() -> Returns the group's volume value.
* volume(id) -> Returns the sound id's current volume.
* volume(vol) -> Sets the volume of all sounds in this Howl group.
* volume(vol, id) -> Sets the volume of passed sound id.
* @return {Howl/Number} Returns self or current volume.
*/
volume: function () {
var self = this;
var args = arguments;
var vol, id;
// Determine the values based on arguments.
if (args.length === 0) {
// Return the value of the groups' volume.
return self._volume;
} else if (args.length === 1) {
// First check if this is an ID, and if not, assume it is a new volume.
var ids = self._getSoundIds();
var index = ids.indexOf(args[0]);
if (index >= 0) {
id = parseInt(args[0], 10);
} else {
vol = parseFloat(args[0]);
}
} else if (args.length === 2) {
vol = parseFloat(args[0]);
id = parseInt(args[1], 10);
}
// Update the volume or return the current volume.
var sound;
if (typeof vol !== 'undefined' && vol >= 0 && vol <= 1) {
// Wait for the sound to begin playing before changing the volume.
if (!self._loaded) {
self.once('play', function () {
self.volume.apply(self, args);
});
return self;
}
// Set the group volume.
if (typeof id === 'undefined') {
self._volume = vol;
}
// Update one or all volumes.
id = self._getSoundIds(id);
for (var i = 0; i < id.length; i++) {
// Get the sound.
sound = self._soundById(id[i]);
if (sound) {
sound._volume = vol;
if (self._webAudio && sound._node) {
sound._node.gain.setValueAtTime(vol * Howler.volume(), ctx.currentTime);
} else if (sound._node) {
sound._node.volume = vol * Howler.volume();
}
}
}
} else {
sound = id ? self._soundById(id) : self._sounds[0];
return sound ? sound._volume : 0;
}
return self;
},
/**
* Fade a currently playing sound between two volumes (if no id is passsed, all sounds will fade).
* @param {Number} from The value to fade from (0.0 to 1.0).
* @param {Number} to The volume to fade to (0.0 to 1.0).
* @param {Number} len Time in milliseconds to fade.
* @param {Number} id The sound id (omit to fade all sounds).
* @return {Howl}
*/
fade: function (from, to, len, id) {
var self = this;
// Wait for the sound to play before fading.
if (!self._loaded) {
self.once('play', function () {
self.fade(from, to, len, id);
});
return self;
}
// Set the volume to the start position.
self.volume(from, id);
// Fade the volume of one or all sounds.
var ids = self._getSoundIds(id);
for (var i = 0; i < ids.length; i++) {
// Get the sound.
var sound = self._soundById(ids[i]);
// Create a linear fade or fall back to timeouts with HTML5 Audio.
if (sound) {
if (self._webAudio) {
var currentTime = ctx.currentTime;
var end = currentTime + (len / 1000);
sound._volume = from;
sound._node.gain.setValueAtTime(from, currentTime);
sound._node.gain.linearRampToValueAtTime(to, end);
// Fire the event when complete.
setTimeout(function (id, sound) {
setTimeout(function () {
sound._volume = to;
self._emit('faded', id);
}, end - ctx.currentTime > 0 ? Math.ceil((end - ctx.currentTime) * 1000) : 0);
}.bind(self, ids[i], sound), len);
} else {
var diff = Math.abs(from - to);
var dir = from > to ? 'out' : 'in';
var steps = diff / 0.01;
var stepLen = len / steps;
(function () {
var vol = from;
var interval = setInterval(function (id) {
// Update the volume amount.
vol += (dir === 'in' ? 0.01 : -0.01);
// Make sure the volume is in the right bounds.
vol = Math.max(0, vol);
vol = Math.min(1, vol);
// Round to within 2 decimal points.
vol = Math.round(vol * 100) / 100;
// Change the volume.
self.volume(vol, id);
// When the fade is complete, stop it and fire event.
if (vol === to) {
clearInterval(interval);
self._emit('faded', id);
}
}.bind(self, ids[i]), stepLen);
})();
}
}
}
return self;
},
/**
* Get/set the loop parameter on a sound. This method can optionally take 0, 1 or 2 arguments.
* loop() -> Returns the group's loop value.
* loop(id) -> Returns the sound id's loop value.
* loop(loop) -> Sets the loop value for all sounds in this Howl group.
* loop(loop, id) -> Sets the loop value of passed sound id.
* @return {Howl/Boolean} Returns self or current loop value.
*/
loop: function () {
var self = this;
var args = arguments;
var loop, id, sound;
// Determine the values for loop and id.
if (args.length === 0) {
// Return the grou's loop value.
return self._loop;
} else if (args.length === 1) {
if (typeof args[0] === 'boolean') {
loop = args[0];
self._loop = loop;
} else {
// Return this sound's loop value.
sound = self._soundById(parseInt(args[0], 10));
return sound ? sound._loop : false;
}
} else if (args.length === 2) {
loop = args[0];
id = parseInt(args[1], 10);
}
// If no id is passed, get all ID's to be looped.
var ids = self._getSoundIds(id);
for (var i = 0; i < ids.length; i++) {
sound = self._soundById(ids[i]);
if (sound) {
sound._loop = loop;
if (self._webAudio && sound._node) {
sound._node.bufferSource.loop = loop;
}
}
}
return self;
},
/**
* Get/set the seek position of a sound. This method can optionally take 0, 1 or 2 arguments.
* seek() -> Returns the first sound node's current seek position.
* seek(id) -> Returns the sound id's current seek position.
* seek(seek) -> Sets the seek position of the first sound node.
* seek(seek, id) -> Sets the seek position of passed sound id.
* @return {Howl/Number} Returns self or the current seek position.
*/
seek: function () {
var self = this;
var args = arguments;
var seek, id;
// Determine the values based on arguments.
if (args.length === 0) {
// We will simply return the current position of the first node.
id = self._sounds[0]._id;
} else if (args.length === 1) {
// First check if this is an ID, and if not, assume it is a new seek position.
var ids = self._getSoundIds();
var index = ids.indexOf(args[0]);
if (index >= 0) {
id = parseInt(args[0], 10);
} else {
id = self._sounds[0]._id;
seek = parseFloat(args[0]);
}
} else if (args.length === 2) {
seek = parseFloat(args[0]);
id = parseInt(args[1], 10);
}
// If there is no ID, bail out.
if (typeof id === 'undefined') {
return self;
}
// Wait for the sound to load before seeking it.
if (!self._loaded) {
self.once('load', function () {
self.seek.apply(self, args);
});
return self;
}
// Get the sound.
var sound = self._soundById(id);
if (sound) {
if (seek >= 0) {
// Pause the sound and update position for restarting playback.
var playing = self.playing(id);
if (playing) {
self.pause(id, true);
}
// Move the position of the track and cancel timer.
sound._seek = seek;
self._clearTimer(id);
// Restart the playback if the sound was playing.
if (playing) {
self.play(id, true);
}
} else {
if (self._webAudio) {
return (sound._seek + (self.playing(id) ? ctx.currentTime - sound._playStart : 0));