來到第11天，相信大家都有在網站上觀看影片的經驗，這次就來自己打造一個影片的控制列吧。

Day11

Demo
html:放置影片檔案，以及做進度條，音量控制，播放速度控制等input，在快轉或倒轉的button要設定data-skip，之後在js上會抓取此數值，來達到更新影片時間

  <div class="player">
    <video class="player__video viewer" src="./652333414.mp4"></video>

    <div class="player__controls">
      <div class="progress">
        <div class="progress__filled"></div>
      </div>
      <button class="player__button toggle" title="Toggle Play">►</button>
      <input type="range" name="volume" class="player__slider" min="0" max="1" step="0.05" value="1">
      <input type="range" name="playbackRate" class="player__slider" min="0.5" max="2" step="0.1" value="1">
      <button data-skip="-10" class="player__button">« 10s</button>
      <button data-skip="25" class="player__button">25s »</button>
    </div>
  </div>

css:

html {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  padding: 0;
  display: flex;
  background: #7A419B;
  min-height: 100vh;
  background: linear-gradient(135deg, #7c1599 0%,#921099 48%,#7e4ae8 100%);
  background-size: cover;
  align-items: center;
  justify-content: center;
}

.player {
  max-width: 750px;
  border: 5px solid rgba(0,0,0,0.2);
  box-shadow: 0 0 20px rgba(0,0,0,0.2);
  position: relative;
  font-size: 0;
  overflow: hidden;
}

/* This css is only applied when fullscreen is active. */
.player:fullscreen {
  max-width: none;
  width: 100%;
}

.player:-webkit-full-screen {
  max-width: none;
  width: 100%;
}

.player__video {
  width: 100%;
}

.player__button {
  background: none;
  border: 0;
  line-height: 1;
  color: white;
  text-align: center;
  outline: 0;
  padding: 0;
  cursor: pointer;
  max-width: 50px;
}

.player__button:focus {
  border-color: #ffc600;
}

.player__slider {
  width: 10px;
  height: 30px;
}

.player__controls {
  display: flex;
  position: absolute;
  bottom: 0;
  width: 100%;
  transform: translateY(100%) translateY(-5px);
  transition: all .3s;
  flex-wrap: wrap;
  background: rgba(0,0,0,0.1);
}

.player:hover .player__controls {
  transform: translateY(0);
}

.player:hover .progress {
  height: 15px;
}

.player__controls > * {
  flex: 1;
}

.progress {
  flex: 10;
  position: relative;
  display: flex;
  flex-basis: 100%;
  height: 5px;
  transition: height 0.3s;
  background: rgba(0,0,0,0.5);
  cursor: ew-resize;
}

.progress__filled {
  width: 50%;
  background: #ffc600;
  flex: 0;
  flex-basis: 50%;
}

/* unholy css to style input type="range" */

input[type=range] {
  -webkit-appearance: none;
  background: transparent;
  width: 100%;
  margin: 0 5px;
}

input[type=range]:focus {
  outline: none;
}

input[type=range]::-webkit-slider-runnable-track {
  width: 100%;
  height: 8.4px;
  cursor: pointer;
  box-shadow: 1px 1px 1px rgba(0, 0, 0, 0), 0 0 1px rgba(13, 13, 13, 0);
  background: rgba(255,255,255,0.8);
  border-radius: 1.3px;
  border: 0.2px solid rgba(1, 1, 1, 0);
}

input[type=range]::-webkit-slider-thumb {
  height: 15px;
  width: 15px;
  border-radius: 50px;
  background: #ffc600;
  cursor: pointer;
  -webkit-appearance: none;
  margin-top: -3.5px;
  box-shadow:0 0 2px rgba(0,0,0,0.2);
}

input[type=range]:focus::-webkit-slider-runnable-track {
  background: #bada55;
}

input[type=range]::-moz-range-track {
  width: 100%;
  height: 8.4px;
  cursor: pointer;
  box-shadow: 1px 1px 1px rgba(0, 0, 0, 0), 0 0 1px rgba(13, 13, 13, 0);
  background: #ffffff;
  border-radius: 1.3px;
  border: 0.2px solid rgba(1, 1, 1, 0);
}

input[type=range]::-moz-range-thumb {
  box-shadow: 0 0 0 rgba(0, 0, 0, 0), 0 0 0 rgba(13, 13, 13, 0);
  height: 15px;
  width: 15px;
  border-radius: 50px;
  background: #ffc600;
  cursor: pointer;
}

js:主要邏輯為將功能切分成多個function來達到，點擊影片或播放鍵時播放或暫停，更改播放暫停的字樣，當使用者點擊或拖曳更新音量或播放速度等時要更新的function，以下為code及說明

/* Get Our Elements */
    //選取指定元素
    const player = document.querySelector('.player');
    const video = player.querySelector('.viewer');
    const progress = player.querySelector('.progress');
    const progressBar = player.querySelector('.progress__filled');
    const toggle = player.querySelector('.toggle');
    const skipButtons = player.querySelectorAll('[data-skip]');
    const ranges = player.querySelectorAll('.player__slider');

    /* Build out functions */
    //決定video播放或是暫停的function
    function togglePlay() {
      const method = video.paused ? 'play' : 'pause';
      video[method]();
    }
    //改變播放或暫停的顯示字樣
    function updateButton() {
      const icon = this.paused ? '►' : '❚ ❚';
      console.log(icon);
      toggle.textContent = icon;
    }
    //在html上有設定dataset，當點即時執行function，會將目前影片秒數加上dataset的時間
    function skip() {
      video.currentTime += parseFloat(this.dataset.skip);
    }
    //更新音量，目前秒數，播放速度的function
    function handleRangeUpdate() {
      video[this.name] = this.value;
    }
    //video.duration為影片秒數總長度，將目前時間/總秒數後乘以100就是所佔百分比
    //藉此用這百分比去更改css的flexBasis
    function handleProgress() {
      const percent = (video.currentTime / video.duration) * 100;
      progressBar.style.flexBasis = `${percent}%`;
    }
    //用來更新使用者點擊段落後的秒數，e.offsetX為滑鼠點下去的X位置，除以整個進度條長度
    //之後再乘以影片總長度，就能得到目前影片時間，再以此更新
    function scrub(e) {
      const scrubTime = (e.offsetX / progress.offsetWidth) * video.duration;
      video.currentTime = scrubTime;
    }

    /* Hook up the event listeners */
    //綁定點擊、播放、暫停、時間更新、滑鼠移動等事件
    video.addEventListener('click', togglePlay);
    video.addEventListener('play', updateButton);
    video.addEventListener('pause', updateButton);
    video.addEventListener('timeupdate', handleProgress);

    toggle.addEventListener('click', togglePlay);
    skipButtons.forEach(button => button.addEventListener('click', skip));
    ranges.forEach(range => range.addEventListener('change', handleRangeUpdate));
    ranges.forEach(range => range.addEventListener('mousemove', handleRangeUpdate));
    //宣告一個變數來判斷滑鼠左鍵是否按下，當按下時會改為true
    let mousedown = false;
    progress.addEventListener('click', scrub);
    progress.addEventListener('mousemove', (e) => mousedown && scrub(e));
    progress.addEventListener('mousedown', () => mousedown = true);
    progress.addEventListener('mouseup', () => mousedown = false);