Anthony Chao

JS30 day23 Speech Synthesis

#Javascript

JS30 day23 - Speech Synthesis

作業內容

最近做的都跟聲音有關，雖然概念上不複雜但我覺得 Google 能把這個東西實作出來放在瀏覽器真的太猛了吧 = =，這個作業自己覺得比較難的部分是理解整個 google 系統是怎麼把聲音的資訊結合成物件

學到什麼

  • JS

    1. SpeechSynthesisUtterance() 物件為 Web Speech API 中代表一發音的需求，翻成白話文就是一段話的資訊，例如內容，語言、音調、聲音、速率等，我們可以透過 console log 看看這個物件的組成：
    SpeechSynthesisUtterance {text: "", lang: "", voice: null, volume: -1, rate: -1, …}

    發出聲音的方式是用下面的方式來說：

    SpeechSynthesis.speak(<SpeechSynthesisUtterance實體>)

    上面這句的 SpeechSynthesis 介面是語音合成伺服器的控制器，可透過其來取得可使用的語音合成資訊，並播放或暫停發音等相關功能

    1. speechSynthesis.addEventListener('voiceschanged', populatVoices) voiceschanged 事件是當 SpeechSynthesis.getVoices() 改變時被觸發，它也是 SpeechSynthesis 唯一的一個事件。 這裡會被觸發，Bos 是說因為 SpeechSynthesis 被讀取所以觸發了這個事件
    2. SpeechSynthesis.getVoices()：取得一陣列，其中包含目前所有的 SpeechSynthesisVoice 物件，其裡頭的屬性為當下環境支援的所有發音資訊，晚點必須選擇其中一個給 msg 這個實體才有辦法發出聲音
    function populateVoices(){
  voices = this.getVoices()
  console.log(voices)
}

    參考資料：https://ithelp.ithome.com.tw/articles/10196799

    1. 現在要做出在下拉選單選擇不同語言就要發出不同語言的聲音
    function setVoice(){
  msg.voice = voices.find(voice => voice.name === this.value)
}
voicesDropdown.addEventListener('change', setVoice)
    1. 做出切換語言同時直接中段前一個然後發聲音
    function setVoice(){
  msg.voice = voices.find(voice => voice.name === this.value)
  toggle()
}

function toggle(startOver = true){
  speechSynthesis.cancel()
  if (startOver){
    speechSynthesis.speak(msg)
  }
}
    1. 監聽 scroll bar 跟 text 變化
    function setOption(){
  console.log(this.name, this.value);
  msg[${this.name}] = this.value;
  toggle();
}
options.forEach(option => {
  option.addEventListener('change', setOption)
})

    1. 綁定 stopButton 事件的時候注意不能這樣寫
    stopButton.addEventListener('click', toggle(false))

    這樣會只有在一開始的時候觸發一次，按鍵本身沒作用，所以有兩種寫法 bind() 會生成一個新的綁定函式，第一個值是 this 的值，後面的才是第 1,2,3…個參數

    stopButton.addEventListener('click', toggle.bind(null, false))  
// 或者
stopButton.addEventListener('click', () => toggle(false))
    1. 經過自己分析之後，發出聲音的步驟可以拆解如下如下
    //1.把瀏覽器可以發出的聲音列出來，放在下拉選單(window 會比 mac 少)，這邊的 this 是 speechSynthesis
voices = this.getVoices()
//2.根據使用者選的下拉選單，把指定的這個 vioce 物件塞回去給 SpeechSynthesisUtterance 生出來的實體 msg
msg.voice = voices.find(voice => voice.name === this.value)
//3.根據 input 不同改變這段 msg 的內容 / 速度 / 音高 
msg[this.name] = this.value 
//4.包裝成 toggle function 發出聲音，如果傳入的參數是 false 就可以不發出聲音
function toggle(startOver = true){
  speechSynthesis.cancel()
  if (startOver){
    speechSynthesis.speak(msg)
  }
}

參考資料： https://github.com/wesbos/JavaScript30

code 內容：

HTML:

<div class="voiceinator">

      <h1>The Voiceinator 5000</h1>

      <select name="voice" id="voices">
        <option value="">Select A Voice</option>
      </select>

      <label for="rate">Rate:</label>
      <input name="rate" type="range" min="0" max="3" value="1" step="0.1">

      <label for="pitch">Pitch:</label>

      <input name="pitch" type="range" min="0" max="2" step="0.1">
      <textarea name="text">Hello! I love JavaScript 👍</textarea>
      <button id="stop">Stop!</button>
      <button id="speak">Speak</button>
<option value=""></option>

CSS:

html {
  font-size: 10px;
  box-sizing: border-box;
}

*, *:before, *:after {
  box-sizing: inherit;
}

body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background-color: #3BC1AC;
  display: flex;
  min-height: 100vh;
  align-items: center;

  background-image:
  radial-gradient(circle at 100% 150%, #3BC1AC 24%, #42D2BB 25%, #42D2BB 28%, #3BC1AC 29%, #3BC1AC 36%, #42D2BB 36%, #42D2BB 40%, transparent 40%, transparent),
  radial-gradient(circle at 0    150%, #3BC1AC 24%, #42D2BB 25%, #42D2BB 28%, #3BC1AC 29%, #3BC1AC 36%, #42D2BB 36%, #42D2BB 40%, transparent 40%, transparent),
  radial-gradient(circle at 50%  100%, #42D2BB 10%, #3BC1AC 11%, #3BC1AC 23%, #42D2BB 24%, #42D2BB 30%, #3BC1AC 31%, #3BC1AC 43%, #42D2BB 44%, #42D2BB 50%, #3BC1AC 51%, #3BC1AC 63%, #42D2BB 64%, #42D2BB 71%, transparent 71%, transparent),
  radial-gradient(circle at 100% 50%, #42D2BB 5%, #3BC1AC 6%, #3BC1AC 15%, #42D2BB 16%, #42D2BB 20%, #3BC1AC 21%, #3BC1AC 30%, #42D2BB 31%, #42D2BB 35%, #3BC1AC 36%, #3BC1AC 45%, #42D2BB 46%, #42D2BB 49%, transparent 50%, transparent),
  radial-gradient(circle at 0    50%, #42D2BB 5%, #3BC1AC 6%, #3BC1AC 15%, #42D2BB 16%, #42D2BB 20%, #3BC1AC 21%, #3BC1AC 30%, #42D2BB 31%, #42D2BB 35%, #3BC1AC 36%, #3BC1AC 45%, #42D2BB 46%, #42D2BB 49%, transparent 50%, transparent);
  background-size:100px 50px;
}

.voiceinator {
  padding: 2rem;
  width: 50rem;
  margin: 0 auto;
  border-radius: 1rem;
  position: relative;
  background: white;
  overflow: hidden;
  z-index: 1;
  box-shadow: 0 0 5px 5px rgba(0,0,0,0.1);
}

h1 {
  width: calc(100% + 4rem);
  margin: -2rem 0 2rem -2rem;
  padding: .5rem;
  background: #ffc600;
  border-bottom: 5px solid #F3C010;
  text-align: center;
  font-size: 5rem;
  font-weight: 100;
  font-family: 'Pacifico', cursive;
  text-shadow: 3px 3px 0 #F3C010;
}

.voiceinator input,
.voiceinator button,
.voiceinator select,
.voiceinator textarea {
  width: 100%;
  display: block;
  margin: 10px 0;
  padding: 10px;
  border: 0;
  font-size: 2rem;
  background: #F7F7F7;
  outline: 0;
}

textarea {
  height: 20rem;
}

input[type="select"] {

}

.voiceinator button {
  background: #ffc600;
  border: 0;
  width: 49%;
  float: left;
  font-family: 'Pacifico', cursive;
  margin-bottom: 0;
  font-size: 2rem;
  border-bottom: 5px solid #F3C010;
  cursor: pointer;
  position: relative;
}

.voiceinator button:active {
  top: 2px;
}

.voiceinator button:nth-of-type(1) {
  margin-right: 2%;
}

JS:

const msg = new SpeechSynthesisUtterance();
let voices = [];
const voicesDropdown = document.querySelector('[name="voice"]');
const options = document.querySelectorAll('[type="range"], [name="text"]');
const speakButton = document.querySelector('#speak');
const stopButton = document.querySelector('#stop');
msg.text = document.querySelector('[name="text"]').value

function populateVoices(){
  voices = this.getVoices()
  const voiceOptions = voices
    .map( voice => { return `<option value="${voice.name}">${voice.name}(${voice.lang})</option>`})
    .join('')
  voicesDropdown.innerHTML = voiceOptions
}

function setVoice(){
  msg.voice = voices.find(voice => voice.name === this.value)
  toggle()
}

function toggle(startOver = true){
  speechSynthesis.cancel()
  if (startOver){
    speechSynthesis.speak(msg)
  }
}

function setOption(){
  msg[this.name] = this.value;
  toggle();
}

speechSynthesis.addEventListener('voiceschanged', populateVoices)
voicesDropdown.addEventListener('change', setVoice)
options.forEach(option => {
  option.addEventListener('change', setOption)
})
speakButton.addEventListener('click', toggle.bind(null, false))
stopButton.addEventListener('click', toggle(false))