JavaScript旋转木马轮播图

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>旋转木马轮播图</title>
    <link rel="stylesheet" href="css/css.css"/>
    <script src="common.js"></script>
    <script>
        //
        var config = [
            {
                width: 400,
                top: 20,
                left: 50,
                opacity: 0.2,
                zIndex: 2
            },//0
            {
                width: 600,
                top: 70,
                left: 0,
                opacity: 0.8,
                zIndex: 3
            },//1
            {
                width: 800,
                top: 100,
                left: 200,
                opacity: 1,
                zIndex: 4
            },//2
            {
                width: 600,
                top: 70,
                left: 600,
                opacity: 0.8,
                zIndex: 3
            },//3
            {
                width: 400,
                top: 20,
                left: 750,
                opacity: 0.2,
                zIndex: 2
            }//4

        ];

        //页面加载的事件
        window.onload = function () {
            var flag = true;//假设所有的动画都执行完毕
            //获取所有的li标签循环遍历设置样式
            var list = my$("slide").getElementsByTagName("li");

            function assign() {
                for (var i = 0; i < list.length; i++) {
                    animate(list[i], config[i], function () {
                        flag = true;
                    });
                }
            }

            assign();
            //鼠标进入跟鼠标离开事件
            my$("wrap").onmouseover = function () {
                animate(my$("arrow"), {"opacity": 1});
            };
            my$("wrap").onmouseout = function () {
                animate(my$("arrow"), {"opacity": 0})
            };

            //右边按钮
            my$("arrRight").onclick = function () {
                if (flag) {
                    flag = false;
                    config.push(config.shift());//把数组的第一个元素放到最后一个
                    assign();//重新分配
                }
            };
            //左边按钮
            my$("arrLeft").onclick = function () {
                if (flag) {
                    flag = false;
                    config.unshift(config.pop());//吧数组中的最后一个元素放到第一个
                    assign();//重新分配
                }
            }
        };

    </script>

</head>
<body>
<div class="wrap" id="wrap">
    <div class="slide" id="slide">
        <ul>
            <li><a href="#"><img src="images/slidepic1.jpg" alt=""/></a></li>
            <li><a href="#"><img src="images/slidepic2.jpg" alt=""/></a></li>
            <li><a href="#"><img src="images/slidepic3.jpg" alt=""/></a></li>
            <li><a href="#"><img src="images/slidepic4.jpg" alt=""/></a></li>
            <li><a href="#"><img src="images/slidepic5.jpg" alt=""/></a></li>
        </ul>
        <div class="arrow" id="arrow">
            <a href="javascript:;" class="prev" id="arrLeft"></a>
            <a href="javascript:;" class="next" id="arrRight"></a>
        </div>
    </div>
</div>

</body>
</html>

css.css

@charset "UTF-8";
/*初始化  reset*/
blockquote,body,button,dd,dl,dt,fieldset,form,h1,h2,h3,h4,h5,h6,hr,input,legend,li,ol,p,pre,td,textarea,th,ul{margin:0;padding:0}
body,button,input,select,textarea{font:12px/1.5 "Microsoft YaHei", "微软雅黑", SimSun, "宋体", sans-serif;color: #666;}
ol,ul{list-style:none}
a{text-decoration:none}
fieldset,img{border:0;vertical-align:top;}
a,input,button,select,textarea{outline:none;}
a,button{cursor:pointer;}

.wrap{
    width:1200px;
    margin:100px auto;
}
.slide {
    height:500px;
    position: relative;
}
.slide li{
    position: absolute;
    left:200px;
    top:0;
}
.slide li img{
    width:100%;
}
.arrow{
    opacity: 0;
}
.prev,.next{
    width:76px;
    height:112px;
    position: absolute;
    top:50%;
    margin-top:-56px;
    background: url(../images/prev.png) no-repeat;
    z-index: 99;
}
.next{
    right:0;
    background-image: url(../images/next.png);
}

common.js

//根据id获取对应的元素
function my$(id) {
    return document.getElementById(id);
}
/*
* element---任意的元素
* attr---属性
* */
function getAttrValue(element,attr) {
    return element.currentStyle?element.currentStyle[attr] : window.getComputedStyle(element,null)[attr]||0;
}

/*
* element----要移动的元素
* target----移动的目标
* 初级版本
* */
/*
* 终极版本的动画函数---有bug
*
* */
function animate(element,json,fn) {
    clearInterval(element.timeId);
    element.timeId=setInterval(function () {
        var flag=true;//假设都达到了目标
        for(var attr in json){
            if(attr=="opacity"){//判断属性是不是opacity
                var current= getAttrValue(element,attr)*100;
                //每次移动多少步
                var target=json[attr]*100;//直接赋值给一个变量,后面的代码都不用改
                var step=(target-current)/10;//(目标-当前)/10
                step=step>0?Math.ceil(step):Math.floor(step);
                current=current+step;
                element.style[attr]=current/100;
            }else if(attr=="zIndex"){//判断属性是不是zIndex
                element.style[attr]=json[attr];
            }else{//普通的属性

                //获取当前的位置----getAttrValue(element,attr)获取的是字符串类型
                var current= parseInt(getAttrValue(element,attr))||0;
                //每次移动多少步
                var target=json[attr];//直接赋值给一个变量,后面的代码都不用改
                var step=(target-current)/10;//(目标-当前)/10
                step=step>0?Math.ceil(step):Math.floor(step);
                current=current+step;
                element.style[attr]=current+"px";
            }
            if(current!=target){
                flag=false;//如果没到目标结果就为false
            }
        }
        if(flag){//结果为true
            clearInterval(element.timeId);
            if(fn){//如果用户传入了回调的函数
                fn(); //就直接的调用,
            }
        }
        console.log("target:"+target+"current:"+current+"step:"+step);
    },10);
}