google_tts.js

const Gst = imports.gi.Gst;

const URI =
    "https://translate.google.com/translate_tts?client=tw-ob&ie=UTF-8&total=1&idx=0&textlen=%d&q=%s&tl=%s";
const MAX_LEN = 100;

var GoogleTTS = class GoogleTTS {
    constructor() {
        Gst.init(null);

        this._player = Gst.ElementFactory.make("playbin", "player");
        this._bus = this._player.get_bus();
        this._bus.add_signal_watch();

        this._bus.connect("message::error", () => this._kill_stream());
        this._bus.connect("message::eos", () => this._kill_stream());
    }

    _kill_stream() {
        this._player.set_state(Gst.State.NULL);
    }

    speak(text, lang) {
        let extract = text.substr(0, MAX_LEN - 1);
        this._kill_stream();

        let uri = URI.format(extract.length, encodeURIComponent(extract), lang);
        this._player.set_property("uri", uri);
        this._player.set_state(Gst.State.PLAYING);
    }

    destroy() {
        this._player.set_state(Gst.State.NULL);
    }
};