基于OO的动画附加插件,可以实现弹跳、渐隐等动画效果 分享_javascript技巧

/*
 createByTommy_20110525
 emial:@csslife@163.com
 用途：
 执行渐隐等动画效果
 传入参数说明：
 1、第一个参数为需要变换对象或ID；
 2、第二个参数为一个对象包含：
 1)、sty->变换对象需要改变的属性，默认为改变宽度（也可以传非style的属性比如scrollTop等）
 2)、curClass->变换对象完成改变后需要添加的当前类,默认为空
 3)、maxVal->改变属于的最大值，默认为0（如果curClass为宽高等style属性表示隐藏），当这个要改变的属性值达到时停止动画
 4)、effect->执行的动画效果默认为outQuad，如需弹跳效果将其值设置为2
 3、最后个参数为可选参数表示当动画执行完毕后运行的回调函数
 */

//animation
var ani = function(){this.init.apply(this,arguments)}
ani.prototype = {
    _id:function(i){
        if(!i) return;
        return typeof i != "string" && i.nodeType === 1 ? i : document.getElementById(i);
    },
    init:function(e,s,callback){
        this.e = this._id(e);
        this.setInit(s||{});
        var maxS = parseInt(this.s.maxVal),speed = maxS==0?Math.max(this.getSty(this.e,this.s.sty),1):maxS/5;
        this.fun(speed,maxS,callback)
    },
    formula:function(x){
        var f;
        switch(this.s.effect){
            case 0:
                f = "outQuad";
                break;
            case 1:
                f = "inQuad";
                break;
            case 2:
                f = "bounce";
                break;
            default:
                f = "easeInBack";
        }
        this.tween ={
            outQuad:function(pos){return Math.pow(pos, 2)},//outQuad
            inQuad:function(pos){return -(Math.pow((pos-1),2)-1)},//inQuad
            bounce:function(pos){//bounce
                if (pos                     return (7.5625 * pos * pos);
                } else if (pos                     return (7.5625 * (pos -= (1.5 / 2.75)) * pos + .75);
                } else if (pos                     return (7.5625 * (pos -= (2.25 / 2.75)) * pos + .9375);
                } else {
                    return (7.5625 * (pos -= (2.625 / 2.75)) * pos + .984375);
                }
            },
            easeInBack:function(pos){var s = 1.70158;return (pos) * pos * ((s + 1) * pos - s);}
        };
        return this.tween[f](x);
    },
    findAry:function(attr){
        var rg = ["width","height","top","bottom","left","right","margin","padding"];
        for(var z in rg){
            if(rg[z]==attr) return true;
        }
        return false;
    },
    setInit:function(s){
        this.s = {
            sty:"width",
            curClass:"",
            maxVal:0,//效果最大值
            effect:1//执行效果
        }
        for(i in s) this.s[i] = s[i];
    },
    setSty:function(x){
        var attr = this.s.sty;
        if(this.findAry(attr)){
            this.e.style[attr] = x + 'px';
            var isIE6 = navigator.appVersion.indexOf("MSIE 6")>-1;
            isIE6&&attr=="top"&&(this.e.style[attr] = x + document.documentElement.scrollTop + 'px');
        }else if(attr=="opacity"){
            this.s.maxVal===1&&(this.e.style.display = "block");
            this.e.style.opacity = x;
            this.e.style.filter = "alpha(opacity="+x*100+")";
        }else{
            this.e[this.s.sty] = x
        }
    },
    getSty:function(e,s){
        var val = e.currentStyle?e.currentStyle[s]:document.defaultView.getComputedStyle(e,null)[s];
        return parseInt(val)||0;
    },
    fun:function(f,m,callback){
        var D = Date,t = new D,e,T = 500,_this = this;
        return e = setInterval(function() {
            var z = Math.min(1, (new D - t) / T),
                c = _this.s.curClass,
                curC = _this.e.className;
            _this.setSty( + f + (m - f) * _this.formula(z));
            if (z == 1) {
                if (callback && typeof callback == 'function') callback();
                _this.s.maxVal==0&&(_this.e.getAttribute("style"))&&(_this.e.style.display="none");
                if(c!=""&&curC.indexOf(c)                clearInterval(e);
            }
        },10);
    }
}