效果图
在线效果
第28天的挑战主要是拖拽右边的进度条来设置当前视频的播放速率。
HTML 源码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Video Speed Scrubber</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="wrapper">
<video class="flex" width="765" height="430" src="https://www.dropbox.com/s/nf6jfkwck1glsyo/12%20-%20flex-wrapping-and-columns.mp4?dl=1"
loop controls></video>
<div class="speed">
<div class="speed-bar">1×</div>
</div>
</div>
</body>
</html>
由上面的代码不难看出,UI由左边的一个video和右边的一个div组成。
CSS 代码
body {
margin: 0;
display: flex;
justify-content: center;
align-items: center;
min-height: 100vh;
background: #4C4C4C url('https://unsplash.it/1500/900?image=1021');
background-size: cover;
font-family: sans-serif;
}
.wrapper {
width: 850px;
display: flex;
}
video {
box-shadow: 0 0 1px 3px rgba(0, 0, 0, 0.1);
}
.speed {
background: #efefef;
flex: 1;
display: flex;
align-items: flex-start;
margin: 10px;
border-radius: 50px;
box-shadow: 0 0 1px 3px rgba(0, 0, 0, 0.1);
overflow: hidden;
}
.speed-bar {
width: 100%;
background: linear-gradient(-170deg, #2376ae 0%, #c16ecf 100%);
text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.2);
display: flex;
align-items: center;
justify-content: center;
padding: 2px;
color: white;
height: 16.3%;
}
JS 源码
<script>
const speed = document.querySelector('.speed');
const bar = speed.querySelector('.speed-bar');
const video = document.querySelector('.flex');
function handleMove(e) {
const y = e.pageY - this.offsetTop;
const percent = y / this.offsetHeight;
const min = 0.4;
const max = 4;
const height = Math.round(percent * 100) + '%';
const playbackRate = percent * (max - min) + min;
bar.style.height = height;
bar.textContent = playbackRate.toFixed(2) + '×';
video.playbackRate = playbackRate;
}
speed.addEventListener('mousemove', handleMove);
</script>
代码逻辑:
- 获取组建
const speed = document.querySelector('.speed');
const bar = speed.querySelector('.speed-bar');
const video = document.querySelector('.flex');
- 监听
speed
控件,鼠标是否处于移动状态,如果在移动,调用handleMove
函数。
speed.addEventListener('mousemove', handleMove);
- 改变
speed
的状态,以及及时更新video
的playbackRate
属性以改变播放速率
function handleMove(e) {
const y = e.pageY - this.offsetTop;
const percent = y / this.offsetHeight;
const min = 0.4;
const max = 4;
const height = Math.round(percent * 100) + '%';
const playbackRate = percent * (max - min) + min;
bar.style.height = height;
bar.textContent = playbackRate.toFixed(2) + '×';
video.playbackRate = playbackRate;
}
源码下载
Github Source Code