仿JQuery的show与hide动画函数

时间：2010-09-17 来源：Floyd

首先介绍两个工具函数：

1     //根据ID返回dom元素
2     var $ = function(id){return document.getElementById(id);}
3     //返回dom元素的当前某css值
4     var getCss = function(obj,name){
5         //ie
6         if(obj.currentStyle) {
7             return obj.currentStyle[name];
8         }
9         //ff
10         else {
11             var style = document.defaultView.getComputedStyle(obj,null);
12             return style[name];
13         }
14     }

Hide函数：

1 var hide = function(obj,speed,fn){

2
3         obj = $(obj);
4
5         if (!speed) {
6             obj.style.display = 'none';
7             return;
8         }
9         else{
10             speed = speed==='fast'?30:speed==='normal'?50:70;
11             obj.style.overflow = 'hidden';
12         }
13         //获取dom的宽与高
14         var oWidth = getCss(obj,'width'), oHeight = getCss(obj,'height');
15         //每次dom的递减数(等比例)
16         var wcut = 20*(+oWidth.replace('px','') / +oHeight.replace('px','')),hcut = 20;
17         //处理动画函数
18         var process = function(width,height){
19             width = +width-wcut>0?+width-wcut:0;
20             height = +height-hcut>0?+width-hcut:0;
21             //判断是否减完了
22             if(width !== 0 || height !== 0) {
23                 obj.style.width = width+'px';
24                 obj.style.height = height+'px';
25
26                 setTimeout(function(){process(width,height);},speed);
27             }
28             else {
29                 //减完后，设置属性为隐藏以及原本dom的宽与高
30                 obj.style.display = 'none';
31                 obj.style.width = oWidth;
32                 obj.style.height = oHeight;
33                 if(fn)fn.call(obj);
34             }
35         }
36         process(oWidth.replace('px',''),oHeight.replace('px',''));
37     }

Show函数与Hide函数类似，只是思路相反而已

1     var show = function(obj,speed,fn){
2
3         obj = $(obj);
4
5         if (!speed) {
6             obj.style.display = 'block';
7             return;
8         }
9         else{
10             speed = speed==='fast'?30:speed==='normal'?50:70;
11             obj.style.overflow = 'hidden';
12         }
13
14         var oWidth = getCss(obj,'width').replace('px',''), oHeight = getCss(obj,'height').replace('px','');
15         var wadd = 20*(+oWidth / +oHeight),hadd = 20;
16
17         obj.style.width = 0+'px';
18         obj.style.height = 0+'px';
19         obj.style.display = 'block';
20
21         var process = function(width,height){
22             width = +oWidth-width<wadd?+oWidth:wadd+width;
23             height = +oHeight-height<hadd?oHeight:hadd+height;
24
25             if(width !== +oWidth || height !== +oHeight) {
26                 obj.style.width = width+'px';
27                 obj.style.height = height+'px';
28
29                 setTimeout(function(){process(width,height);},speed);
30             }
31             else {
32                 obj.style.width = oWidth+'px';
33                 obj.style.height = oHeight+'px';
34                 if(fn)fn.call(obj);
35             }
36         }
37         process(0,0);
38     }

调用方式如：

1 hide('a','normal',function(){
2 show('a','normal');
3 });

呃。。。感觉写得好冗余，但不知要如何再优化，希望有高手能写个精简些的。。。