/* * Copyright (C) 2019-2021 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/>. */ /* global * TextToSpeechAudio */ class AudioSystem extends EventDispatcher { constructor() { super(); this._fallbackAudio = null; } 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); } } getFallbackAudio() { if (this._fallbackAudio === null) { this._fallbackAudio = new Audio('/data/audio/button.mp3'); } return this._fallbackAudio; } createAudio(url, source) { return new Promise((resolve, reject) => { const audio = new Audio(url); audio.addEventListener('loadeddata', () => { if (!this._isAudioValid(audio, source)) { reject(new Error('Could not retrieve audio')); } else { resolve(audio); } }); audio.addEventListener('error', () => reject(audio.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 _onVoicesChanged(e) { this.trigger('voiceschanged', e); } _isAudioValid(audio, source) { switch (source) { case 'jpod101': { const duration = audio.duration; return ( duration !== 5.694694 && // Invalid audio (Chrome) duration !== 5.720718 // Invalid audio (Firefox) ); } default: return true; } } _getTextToSpeechVoiceFromVoiceUri(voiceUri) { try { for (const voice of speechSynthesis.getVoices()) { if (voice.voiceURI === voiceUri) { return voice; } } } catch (e) { // NOP } return null; } }