/* * Copyright (C) 2023 Yomitan Authors * Copyright (C) 2019-2022 Yomichan Authors * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ import {EventDispatcher} from '../core.js'; import {TextToSpeechAudio} from './text-to-speech-audio.js'; /** * @augments EventDispatcher<import('audio-system').EventType> */ export class AudioSystem extends EventDispatcher { constructor() { super(); /** @type {?HTMLAudioElement} */ this._fallbackAudio = null; } /** * @returns {void} */ prepare() { // speechSynthesis.getVoices() will not be populated unless some API call is made. if ( typeof speechSynthesis !== 'undefined' && typeof speechSynthesis.addEventListener === 'function' ) { speechSynthesis.addEventListener('voiceschanged', this._onVoicesChanged.bind(this), false); } } /** * @returns {HTMLAudioElement} */ getFallbackAudio() { if (this._fallbackAudio === null) { this._fallbackAudio = new Audio('/data/audio/button.mp3'); } return this._fallbackAudio; } /** * @param {string} url * @param {import('settings').AudioSourceType} sourceType * @returns {Promise<HTMLAudioElement>} */ async createAudio(url, sourceType) { const audio = new Audio(url); await this._waitForData(audio); if (!this._isAudioValid(audio, sourceType)) { throw new Error('Could not retrieve audio'); } return audio; } /** * @param {string} text * @param {string} voiceUri * @returns {TextToSpeechAudio} * @throws {Error} */ createTextToSpeechAudio(text, voiceUri) { const voice = this._getTextToSpeechVoiceFromVoiceUri(voiceUri); if (voice === null) { throw new Error('Invalid text-to-speech voice'); } return new TextToSpeechAudio(text, voice); } // Private /** * @param {Event} event */ _onVoicesChanged(event) { this.trigger('voiceschanged', event); } /** * @param {HTMLAudioElement} audio * @returns {Promise<void>} */ _waitForData(audio) { return new Promise((resolve, reject) => { audio.addEventListener('loadeddata', () => resolve()); audio.addEventListener('error', () => reject(audio.error)); }); } /** * @param {HTMLAudioElement} audio * @param {import('settings').AudioSourceType} sourceType * @returns {boolean} */ _isAudioValid(audio, sourceType) { switch (sourceType) { case 'jpod101': { const duration = audio.duration; return ( duration !== 5.694694 && // Invalid audio (Chrome) duration !== 5.651111 // Invalid audio (Firefox) ); } default: return true; } } /** * @param {string} voiceUri * @returns {?SpeechSynthesisVoice} */ _getTextToSpeechVoiceFromVoiceUri(voiceUri) { try { for (const voice of speechSynthesis.getVoices()) { if (voice.voiceURI === voiceUri) { return voice; } } } catch (e) { // NOP } return null; } }