js动画之链式运动
链式运动就是当一个运动完，又启动另外一个运动，这个怎么实现呢？这里我们是用用回调函数实现一套链式动画
显示给div左移100像素，然后然后透明度变100
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>链式运动</title>
<style>
.animation{
background-color: green;
height: 200px;
width: 200px;
position: absolute;
opacity: 0.3;
left:0px;
filter:alpha(opacity:30);
}
</style>
</head>
<body>
<div id="test" class="animation" ></div>
</body>
<script type="text/javascript">
window.onload = function(){
var ele = document.getElementById("test"),
timer = null;
//alert(getStyle(ele,'opacity'))
ele.onmouseover = function(){
startAnimation(ele,'left',100,function(){
startAnimation(ele,'opacity',100);
});
}
function startAnimation(node,attr,target,fn){
//1.清空定时器
clearInterval(timer);
//2.重新生成一个定时器
timer = setInterval(function(){
var _currentAttrValue = null
if(attr == 'opacity'){
_currentAttrValue = Math.round(parseFloat(getStyle(node,attr))*100);
}else{
_currentAttrValue = parseInt(getStyle(node,attr));
}
//3.当对应的属性到达了目标想要的属性，那么就清除定时器，并调用回调函数
if(_currentAttrValue == target){
clearInterval(timer);
if(fn){
fn();
}
}else{
_currentAttrValue ++ ;
if(attr == 'opacity'){
node.style[attr] = _currentAttrValue/100;
node.style.filter = 'alpha(opacity:'+_currentAttrValue+')';
}else{
console.log(_currentAttrValue);
node.style[attr] = _currentAttrValue+'px';
}
}
},10)
}
function getStyle(ele,attr){
if(window.getComputedStyle){
return getComputedStyle(ele,null)[attr];
}else{
return ele.currentStyle[attr];
}
}
}
</script>
</html>
大家可以看看效果
