Source: sound/Sound.js

/** @module sound */
/**
 * Sound stimulus.
 * 
 * @author Alain Pitiot
 * @version 3.1.4
 * @copyright (c) 2019 Ilixa Ltd. ({@link http://ilixa.com})
 * @license Distributed under the terms of the MIT License
 */

import { PsychoJS } from '../core/PsychoJS';
import { PsychObject } from '../util/PsychObject';
import { TonePlayer } from './TonePlayer';
import { TrackPlayer } from './TrackPlayer';


/**
 * <p>This class handles sound playing (tones and tracks)</p>
 * 
 * <ul>
 * <li> If value is a number then a tone will be generated at that frequency in Hz.</li>
 * <li> It value is a string, it must either be a note in the PsychoPy format (e.g 'A', 'Bfl', 'B', 'C', 'Csh'), in which case an octave must also be given, or the name of the resource track.</li>
 * </ul>
 * 
 * @example
 * [...]
 * const track = new Sound({
 *   win: psychoJS.window,
 *   value: 440,
 *   secs: 0.5
 * });
 * track.setVolume(1.0);
 * track.play(2);
 *
 * @class
 * @extends PsychObject
 * @param {Object} options
 * @param {String} options.name - the name used when logging messages from this stimulus
 * @param {Window} options.win - the associated Window
 * @param {number|string} [options.value= 'C'] - the sound value (see above for a full description)
 * @param {number} [options.octave= 4] - the octave corresponding to the tone (if applicable)
 * @param {number} [options.secs= 0.5] - duration of the tone (in seconds)
 * @param {number} [options.startTime= 0] - start of playback for tracks (in seconds)
 * @param {number} [options.stopTime= -1] - end of playback for tracks (in seconds)
 * @param {boolean} [options.stereo= true] whether or not to play the sound or track in stereo
 * @param {number} [options.volume= 1.0] - volume of the sound (must be between 0 and 1.0)
 * @param {number} [options.loops= 0] - how many times to repeat the track or tone after it has played once. If loops == -1, the track or tone will repeat indefinitely until stopped.
 * @param {boolean} [options.hamming= true] whether or not to apodize the sound (i.e., the onset and offset smoothly ramped up from down to zero). This only affects tones.
 * @param {boolean} [options.autoLog= true] whether or not to log
*/
export class Sound extends PsychObject {
	constructor({
		name,
		win,
		value = 'C',
		octave = 4,
		secs = 0.5,
		startTime = 0,
		stopTime = -1,
		stereo = true,
		volume = 1.0,
		loops = 0,
		hamming = true,
		autoLog = true
	} = {}) {
		super(win._psychoJS, name);

		// the SoundPlayer, e.g. TonePlayer:
		this._player = undefined;

		this._addAttributes(Sound, win, value, octave, secs, startTime, stopTime, stereo, volume, loops, hamming, autoLog);

		// identify an appropriate player:
		this._getPlayer();

		this.status = PsychoJS.Status.NOT_STARTED;
	}


	/**
	 * Start playing the sound.
	 *
	 * <p> Note: Sounds are played independently from the stimuli of the experiments, i.e. the experiment will not stop until the sound is finished playing.
	 * Repeat calls to play may results in the sounds being played on top of each other.</p>
	 * 
	 * @public
	 * @param {number} [loops= 0] how many times to repeat the sound after it plays once. If loops == -1, the sound will repeat indefinitely until stopped.
	 * @param {boolean} [log= true] whether or not to log
	 */
	play(loops, log = true) {
		this.status = PsychoJS.Status.STARTED;
		this._player.play(loops);
	}


	/**
	 * Stop playing the sound immediately.
	 *
	 * @public
	 * @param {Object} options
	 * @param {boolean} [options.log= true] - whether or not to log
	 */
	stop({
		log = true
	} = {}) {
		this._player.stop();
		this.status = PsychoJS.Status.STOPPED;
	}


	/**
	 * Get the duration of the sound, in seconds.
	 *
	 * @public
	 * @return {number} the duration of the sound, in seconds
	 */
	getDuration() {
		return this._player.getDuration();
	}


	/**
	 * Set the playing volume of the sound.
	 *
	 * @public 
	 * @param {number} volume - the volume (values should be between 0 and 1)
	 * @param {booleam} [mute= false] - whether or not to mute the sound
	 * @param {boolean} [log= true] - whether of not to log
	 */
	setVolume(volume, mute = false, log = true) {
		this._setAttribute('volume', volume, log);
		if (typeof this._player !== 'undefined')
			this._player.setVolume(volume, mute);
	}


	/**
	 * Set the number of loops.
	 *
	 * @public 
	 * @param {number} [loops=0] - how many times to repeat the sound after it has played once. If loops == -1, the sound will repeat indefinitely until stopped.
	 * @param {boolean} [log=true] - whether of not to log
	 */
	setLoops(loops = 0, log = true) {
		this._setAttribute('loops', loops, log);
		if (typeof this._player !== 'undefined')
			this._player.setLoops(loops);
	}


	/**
	 * Identify the appropriate player for the sound.
	 *
	 * @protected
	 * @return {SoundPlayer} the appropriate SoundPlayer
	 * @throws {Object.<string, *>} exception if no appropriate SoundPlayer could be found for the sound
	 */
	_getPlayer() {
		const acceptFns = [
			sound => TonePlayer.accept(sound),
			sound => TrackPlayer.accept(sound)
		];

		for (const acceptFn of acceptFns) {
			this._player = acceptFn(this);
			if (typeof this._player !== 'undefined')
				return;
		}

		throw { origin: 'SoundPlayer._getPlayer', context: 'when finding a player for the sound', error: 'could not find an appropriate player.' };
	}


}