写了一个好玩的弹性列表效果
闲来没事，随遍写写，有需要的尽管拿去用。
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
#list{
width:302px;
margin:50px auto;
padding:0;
list-style: none;
}
#list li{
height:40px;
font:12px/40px '宋体';
border:1px solid #000;
position: relative;
cursor: pointer;
}
#list span{
width:12px;
height:12px;
line-height: 12px;
}
</style>
<script>
var Tween = {
linear: function (t, b, c, d){ //匀速
return c*t/d + b;
},
easeIn: function(t, b, c, d){ //加速曲线
return c*(t/=d)*t + b;
},
easeOut: function(t, b, c, d){ //减速曲线
return -c *(t/=d)*(t-2) + b;
},
easeBoth: function(t, b, c, d){ //加速减速曲线
if ((t/=d/2) < 1) {
return c/2*t*t + b;
}
return -c/2 * ((--t)*(t-2) - 1) + b;
},
easeInStrong: function(t, b, c, d){ //加加速曲线
return c*(t/=d)*t*t*t + b;
},
easeOutStrong: function(t, b, c, d){ //减减速曲线
return -c * ((t=t/d-1)*t*t*t - 1) + b;
},
easeBothStrong: function(t, b, c, d){ //加加速减减速曲线
if ((t/=d/2) < 1) {
return c/2*t*t*t*t + b;
}
return -c/2 * ((t-=2)*t*t*t - 2) + b;
},
elasticIn: function(t, b, c, d, a, p){ //正弦衰减曲线（弹动渐入）
if (t === 0) {
return b;
}
if ( (t /= d) == 1 ) {
return b+c;
}
if (!p) {
p=d*0.3;
}
if (!a || a < Math.abs(c)) {
a = c;
var s = p/4;
} else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
},
elasticOut: function(t, b, c, d, a, p){ //正弦增强曲线（弹动渐出）
if (t === 0) {
return b;
}
if ( (t /= d) == 1 ) {
return b+c;
}
if (!p) {
p=d*0.3;
}
if (!a || a < Math.abs(c)) {
a = c;
var s = p / 4;
} else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b;
},
elasticBoth: function(t, b, c, d, a, p){
if (t === 0) {
return b;
}
if ( (t /= d/2) == 2 ) {
return b+c;
}
if (!p) {
p = d*(0.3*1.5);
}
if ( !a || a < Math.abs(c) ) {
a = c;
var s = p/4;
}
else {
var s = p/(2*Math.PI) * Math.asin (c/a);
}
if (t < 1) {
return - 0.5*(a*Math.pow(2,10*(t-=1)) *
Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
}
return a*Math.pow(2,-10*(t-=1)) *
Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5 + c + b;
},
backIn: function(t, b, c, d, s){ //回退加速（回退渐入）
if (typeof s == 'undefined') {
s = 1.70158;
}
return c*(t/=d)*t*((s+1)*t - s) + b;
},
backOut: function(t, b, c, d, s){
if (typeof s == 'undefined') {
s = 3.70158; //回缩的距离
}
return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
},
backBoth: function(t, b, c, d, s){
if (typeof s == 'undefined') {
s = 1.70158;
}
if ((t /= d/2 ) < 1) {
return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
}
return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
},
bounceIn: function(t, b, c, d){ //弹球减振（弹球渐出）
return c - Tween['bounceOut'](d-t, 0, c, d) + b;
},
bounceOut: function(t, b, c, d){
if ((t/=d) < (1/2.75)) {
return c*(7.5625*t*t) + b;
} else if (t < (2/2.75)) {
return c*(7.5625*(t-=(1.5/2.75))*t + 0.75) + b;
} else if (t < (2.5/2.75)) {
return c*(7.5625*(t-=(2.25/2.75))*t + 0.9375) + b;
}
return c*(7.5625*(t-=(2.625/2.75))*t + 0.984375) + b;
},
bounceBoth: function(t, b, c, d){
if (t < d/2) {
return Tween['bounceIn'](t*2, 0, c, d) * 0.5 + b;
}
return Tween['bounceOut'](t*2-d, 0, c, d) * 0.5 + c*0.5 + b;
}
}
function getStyle(obj,attr)
{
if(obj.currentStyle){
return obj.currentStyle[attr];
}
else{
return getComputedStyle(obj,false)[attr];
}
}
function starMove(obj,json,time,fx,callBack)
{
var iNowTime=getNow();
var iCur={};
for(var attr in json)
{
if(attr=="opacity")
{
iCur[attr]=Math.round(getStyle(obj,attr)*100);
}
else
{
iCur[attr]=parseInt(getStyle(obj,attr));
}
}
clearInterval(obj.oTimer);
obj.oTimer=setInterval(function(){
var iTime=time-Math.max(0,iNowTime-getNow()+time);
for(var attr in json)
{
var iVal=Tween[fx](iTime,iCur[attr],json[attr]-iCur[attr],time)
if(attr=="opacity")
{
obj.style.opacity=iVal/100;
obj.style.filter="alpha(opacity="+iVal+")"
}
else
{
obj.style[attr]=iVal+"px";
}
}
if(iTime==time)
{
clearInterval(obj.oTimer);
if(callBack)
{
callBack.call(obj);
}
}
},14);
}
function getNow()
{
return new Date().getTime();
}
</script>
<script>
window.onload = function(){
var oList = document.getElementById('list');
var aLi = oList.getElementsByTagName('li');
var iLiHeight = aLi[0].offsetHeight;
for(var i=0;i<aLi.length;i++){
var sHtml = aLi[i].innerHTML;
aLi[i].innerHTML = '';
for(var j=0;j<sHtml.length;j++){
aLi[i].innerHTML += '<span>'+sHtml[j]+'</span>';
}
var aSpan = aLi[i].children;
for(var j=0;j<aSpan.length;j++){
aSpan[j].style.left = aSpan[j].offsetLeft+'px';
aSpan[j].style.top = aSpan[j].offsetTop+'px';
aSpan[j].startTop = aSpan[j].offsetTop;
}
for(var j=0;j<aSpan.length;j++){
aSpan[j].style.position = 'absolute';
(function(aSpan,num2){
var iStart = 0;
var iSpanHeight = aSpan[0].offsetHeight;
aSpan[num2].onmouseover = function(ev){
iStart = ev.clientY;
}
aSpan[num2].onmousemove = function(ev){
var iDis = ev.clientY-iStart;
var iNum = iDis>0 ? 1 : -1;
if(this.startTop+iDis>=0 && this.startTop+iDis<(iLiHeight - iSpanHeight)){
for(var j=0;j<aSpan.length;j++){
if(Math.abs(iDis)>Math.abs(num2-j)){
aSpan[j].style.top = aSpan[j].startTop+(Math.abs(iDis)-Math.abs(num2-j))*iNum+'px';
}else{
aSpan[j].style.top = aSpan[j].startTop+'px';
}
}
}
}
aSpan[num2].onmouseout = function(ev){
for(var j=0;j<aSpan.length;j++){
starMove(aSpan[j],{top:aSpan[j].startTop},500,'elasticOut');
}
}
})(aSpan,j);
}
}
}
</script>
</head>
<body>
<ul id="list">
<li>一个好玩的弹性列表效果一个好玩的弹性列表效果</li>
<li>一个好玩的弹性列表效果一个好玩的弹性列表效果</li>
<li>一个好玩的弹性列表效果一个好玩的弹性列表效果</li>
<li>一个好玩的弹性列表效果一个好玩的弹性列表效果</li>
</ul>
</body>
<script>
</script>
</html>
