slack_speech.js

(() => {
const speak = (body, isRetry) => {
  window.speechSynthesis.cancel()
  if (!body) return;
  console.log('speak ' + body);
  const synth = window.speechSynthesis;
  const allVoices = synth.getVoices();
  const jaVoices = allVoices.filter(v => v.lang === 'ja-JP');
  const voice = jaVoices[0];
  if (!voice && !isRetry) {
    speak(body, true)
  }
  const utter = new SpeechSynthesisUtterance(body);
  utter.voice = voice;
  utter.lang = 'ja-JP';
  utter.pitch = 1
  utter.volume = 1
  utter.rate = 1
  synth.speak(utter)
};
const listen = () => {
  new MutationObserver((mutations, observer) => {
    let phrases = []
    for (const m of mutations) {
      if (m.type !== 'childList') {
        continue
      }
      phrases.push(...Array.from(m.addedNodes).map(n => n.textContent).filter(s => s.length > 0))
    }
    console.log(phrases)
    if (phrases.length > 0) {
      speak(phrases.join("\n"))
    }
  }).observe(document.querySelector('.p-message_pane'), {
    childList: true,
    subtree: true,
  })
};
listen();
})();