如何通过多行实现CSS文本加载动画？

Question

我正在尝试用文本加载动画CSS.我所拥有的是一个黑色的文本,然后当页面加载文本将填充开始填充红色几秒钟.

我面临的问题是文本加载动画工作正常,但是当文本结束并以新行开头时,动画文本仍然在同一行上继续.

我怎样才能解决这个问题？

码:

    body {
    background: #3498db;
    font-family: sans-serif;
    }
    h1 {
        position: relative;
        color: rgba(0, 0, 0, .3);
        font-size: 5em;
        white-space: wrap;
    }
    h1:before {
        content: attr(data-text);
        position: absolute;
        overflow: hidden;
        max-width: 100%;
        white-space: nowrap;
        word-break: break-all;
        color: #fff;
        animation: loading 8s linear;
    }
    @keyframes loading {
        0% {
            max-width: 0;
        }
    }

<h1 data-text="Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.">Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.</h1>

Answer 1

一个想法是考虑使用内联元素的渐变着色.只要留意浏览器支持的background-clip: text

body {
  background: #3498db;
  font-family: sans-serif;
}

h1 {
  font-size: 5em;
}

h1 span {
  background:
    linear-gradient(#fff,#fff) left no-repeat,
    rgba(0, 0, 0, .3);
  background-size:0% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  animation:loading 5s forwards linear;
}

@keyframes loading {
  100% {
    background-size:100% 100%;
  }
}

<h1><span>Suspendisse mollis dolor vitae porta egestas. Nunc nec congue odio.</span></h1>

为了更好地理解它是如何工作的,这里有一个基本的例子,你可以看到内联元素如何表现背景颜色以及它与块级元素的不同之处:

.color {
  font-size: 1.5em;
  line-height: 1.5em;
  border: 2px solid;
  background: linear-gradient(red, red) left no-repeat;
  background-size: 0% 100%;
  animation: change 5s linear forwards;
}

@keyframes change {
  100% {
    background-size: 100% 100%
  }
}

<span class="color">
 lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume 
</span>
<div class="color">
  lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume
</div>

我只是使用相同的逻辑来background-clip:text为文本而不是背景着色:

.color {
  font-size: 1.5em;
  line-height: 1.5em;
  border: 2px solid;
  background: linear-gradient(red, red) left no-repeat;
  background-size: 0% 100%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
  animation: change 5s linear forwards;
}

@keyframes change {
  100% {
    background-size: 100% 100%
  }
}

<span class="color">
 lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume 
</span>
<div class="color">
  lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume lorem ipsume
</div>