仿JQuery的show与hide动画函数

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：

 2     var hide = function(obj,speed,fn){
 3         obj = $(obj);
 4         
 5         if (!speed) {
 6             obj.style.display = 'none';
 7             return;
 8         }
 9         else{
10             speed = speed==='fast'?20:speed==='normal'?30:50;
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 = 10*(+oWidth.replace('px','') / +oHeight.replace('px','')),hcut = 10;
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'?20:speed==='normal'?30:50;
11             obj.style.overflow = 'hidden';
12         }
13         
14         var oWidth = getCss(obj,'width').replace('px',''), oHeight = getCss(obj,'height').replace('px','');
15         var wadd = 10*(+oWidth / +oHeight),hadd = 10;
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：

 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。。。