使用javascript oop开发滑动（slide) 菜单控件

时间：2010-08-20 来源：rentj

这里使用原生的javascript，用面向对象的方式创建一个容易维护使用方便的滑动菜单，调用方式如下：

var $sliding = document.getElementById("silding");
var s1 = new Sliding();
s1.commands = $sliding.getElementsByTagName("dt");
s1.panels = $sliding.getElementsByTagName("dd"); ;
s1.init("mouseover", "active");

演示代码分为slide.js和slide.html两个文件

slide.htm:

代码 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript slide控件演示</title>
<style type="text/css">
    /*reset*/
    dl,ul,li,dt,dd{ margin:0; padding:0; list-style:none; }
    /*silding*/
    .silding{ width:200px; border:1px solid #ccc; line- overflow:hidden;}
    .silding dt{border-bottom:1px solid #ccc; background-color:#bebebe; cursor:pointer}
    .silding dd{ display:none; background:#efefef; overflow:hidden; font-size:12px; }
    .silding .active{ font-weight:bold;}
</style>
<script type="text/javascript" src="slide.js"></script>
</head>

<body>
<div id="silding" class="silding">
    <dl>
        <dt class="active">第一个一级菜单</dt>
           <dd style="display:block;">
            <ul>
                <li><a href="#">第一个二级菜单</a></li>
                <li>第一个二级菜单</li>
                <li>第一个二级菜单</li>
            </ul>
        </dd>
   </dl>
    <dl>
        <dt>第二个一级菜单</dt>
           <dd>
            <ul>
                <li>第二个二级菜单</li>
                <li>第二个二级菜单</li>
                <li>第二个二级菜单</li>
            </ul>
        </dd>
   </dl>
    <dl>
        <dt>第三个一级菜单</dt>
           <dd>
            <ul>
                <li>第三个二级菜单</li>
                <li>第三个二级菜单</li>
                <li>第三个二级菜单</li>
            </ul>
        </dd>
   </dl>
</div>
<script type="text/javascript">
    var $sliding = document.getElementById("silding");
    var s1 = new Sliding();
    s1.commands = $sliding.getElementsByTagName("dt");
    s1.panels = $sliding.getElementsByTagName("dd"); ;
    s1.init("mouseover", "active");
</script>
</body>
</html>

slide.js:

代码
    function Slider(i, panelHeight) { //dto
        this.index = i;
        this.panelHeight = panelHeight;
    }

//class  Sliding {
    function Sliding(activeIndex) {
        this.commands = [];
        this.panels = [];
        this.activeIndex = activeIndex || 0;
        this.sliderCache = {};
    }
    Sliding.prototype = {
        //绑定事件
        init: function(eventName, activeCssClass) {
            var _this = this;
            var cmds = _this.commands;
            _this.activeClass = activeCssClass;
            for (var i = 0, n = cmds.length; i < n; i++) {
                cmds[i]["on" + eventName] = function(e) {
                    _this.handel(this, e);
                }
                cmds[i].index = i;
                if (i == _this.activeIndex) {
                    _this.sliderCache = new Slider(i, _this.panels[i].offsetHeight);
                }
            }

        },
        //事件处理函数
        handel: function(elem, args) {
            var _this = this;
            var index = elem.index;
            var cacheIndex = _this.sliderCache.index;
            var cacheElem =  _this.commands[cacheIndex];
            if (index == cacheIndex) return;
            var showPanel = _this.panels[index];
            var hidePanel = _this.panels[cacheIndex];
            var h = parseInt(_this.sliderCache.panelHeight);
            showPanel.style.height = "0px";
            showPanel.style.display = "block";
            _this.tween(hidePanel, showPanel, h);
            elem.className = _this.activeClass;
            cacheElem.className = cacheElem.className.replace(eval("/ ?"+_this.activeClass+" ?/"),"");
            _this.sliderCache = new Slider(index, h);

        },
        //动画算法
        tween: function(obj0, obj1, h) {
            _this = arguments.callee;
            var step = 20;
            if ("\v" == "v") {
                step = 30;
            }
            if (h > 0) {
                var h0 = obj0.offsetHeight;
                var h1 = obj1.offsetHeight;
                if (h < step) {
                    obj0.style.display = "none";
                    obj0.style.height = (h1 + h) + "px";
                    obj1.style.height = (h1 + h) + "px";

                } else {
                    h = h - step;
                    obj0.style.height = (h0 - step) + "px";
                    obj1.style.height = (h1 + step) + "px";
                    setTimeout(function() {
                        _this(obj0, obj1, h)
                    },
                    50)
                }
            }
        }
    }
//}

上面就所有代码了这里因为是演示所以让HTML CSS尽量的简化，另外使用jquery的 fn.slideUp fn.slideDown 实现起来会更容易不过我作为一个专业的开发者多了解些原生的JS对技术的提高还是很有帮助。