js动画(animate)简单引擎代码示例(3)

$util = {
    /**
    * 类型检测
    */
    type : function(obj){
        var rep = /\[object\s+(\w+)\]/i;
        var str = Object.prototype.toString.call(obj).toLowerCase();
        str.match(rep);
        return RegExp.$1;
    },
    /**
    * 深拷贝
    */
    $unlink :function (object){
        var unlinked;
        switch ($type(object)){
            case 'object':
                unlinked = {};
                for (var p in object) {
                    unlinked[p] = $unlink(object[p]);
                }
            break;
            case 'array':
                unlinked = [];
                for (var i = 0, l = object.length; i < l; i++) {
                    unlinked[i] = $unlink(object[i]);
                }
            break;
            default: return object;
        }
        return unlinked;
    },
    /**
    *Dom 相关操作
    */
    dom:{
        $: function(id) {
            return document.getElementById(id);
        },
        getStyle: function(obj, prop) {
            var style = obj.currentStyle || window.getComputedStyle(obj, '');
            if (obj.style.filter) {
                return obj.style.filter.match(/\d+/g)[0];
            }
            return style[prop];
        },
        setStyle: function(obj, prop, val) {
            switch (prop) {
            case 'opacity':
                if($util.client.browser.ie){
                    obj.style.filter = 'alpha(' + prop + '=' + val*100 + ')'   
                }else{
                    obj.style[prop] = val;
                }
                break;
            default:
                obj.style[prop] = val + 'px';
                break;
            }
        },
        setStyles: function(obj, props) {
            for (var prop in props) {
                switch (prop) {
                case 'opacity':
                    if($util.client.browser.ie){
                        obj.style.filter = 'alpha(' + prop + '=' + props[prop] + ')'       
                    }else{
                        obj.style[prop] = props[prop];
                    }
                    break;
                default:
                    obj.style[prop] = props[prop] + 'px';
                    break;
                }
            }
        }
    },
    /**
    *Event 事件相关
    */
    evt : {
        addEvent : function(oTarget, sEventType, fnHandler) {
            if (oTarget.addEventListener) {
                oTarget.addEventListener(sEventType, fnHandler, false);
            } else if (oTarget.attachEvent) {
                oTarget.attachEvent("on" + sEventType, fnHandler);
            } else {
                oTarget["on" + sEventType] = fnHandler;
            }
        },
        rmEvent : function removeEventHandler (oTarget, sEventType, fnHandler) {
            if (oTarget.removeEventListener) {
                oTarget.removeEventListener(sEventType, fnHandler, false);
            } else if (oTarget.detachEvent) {
                oTarget.detachEvent("on" + sEventType, fnHandler);
            } else {
                oTarget["on" + sEventType] = null;
            }
        }
    },
    /**
    *Ajax 异步加载
    */
    ajax : {
        request:function (options) {
                var xhr, res;
                var url = options.url,
                    context = options.context,
                    success = options.success,
                    type = options.type,
                    datatype = options.datatype,
                    async = options.async,
                    send = options.send,
                    headers = options.headers;

                try {
                    xhr = new XMLHttpRequest();
                } catch(e) {
                    try {
                        xhr = new ActiveXObject('MSXML2.XMLHTTP');
                    } catch(e) {
                        xhr = new ActiveXObject('Microsoft.XMLHTTP');
                    }
                }

                xhr.onreadystatechange = function() {
                    if (xhr.readyState == 4 && xhr.status == 200) {
                        res = xhr.responseText;
                        success(res);
                    }
                }
                xhr.open(type, url, async);
                xhr.send(send);
        }
    },
    /**
    *Array 数组相关
    */
    array : {
        minIndex : function(ary){
            return Math.min.apply(null,ary);   
        },
        maxitem : function(ary){
            return Math.max.apply(null,ary);
        }
    },
    /**
    *Client 客户端检测
    */
    client : function(){
        // 浏览器渲染引擎 engines
        var engine = {           
            ie: 0,
            gecko: 0,
            webkit: 0,
            khtml: 0,
            opera: 0,