一个仿QQ的菜单

效果图：

用法: 

// JScript 文件
// by XiaoNiu  evlion@qq.com
// 2009.4.22 修正在FF下不能使用的BUG
Evlon={};
Evlon.createDelegate = function(instance, method)
{
    return function()
    {
        method.apply(instance, arguments);
    }
}


Evlon.getChildren = function(elmt, filter/* var f = {tagName='li'}*/) {
    var elmts = [];
    var e = elmt.firstChild;
    while (e != null) {
        if (e.nodeType != 3) {
            var valid = true;
            if (filter != null) {
                for (var key in filter) {
                    if (e[key] != filter[key]) {
                        valid = false;
                        break;
                    }
                }
            }
            if (valid) {
                elmts.push(e);
            }
        }

        e = e.nextSibling;
    }
    return elmts;
}

Evlon.MenuItem = function(menuWrap, elmt, menuFocusClassName) {
    this.menuWrap = menuWrap;
    this.elmt = elmt;
    this.menuFocusClassName = menuFocusClassName;
    this.onclickHandle = this.elmt.onclick;
    this.elmt.onclick = null;

    this.hide = function() {
        var re = new RegExp("\\s+" + menuFocusClassName, "ig");
        var className = ' ' + this.elmt.className.toString();
        this.elmt.className = className.replace(re, '');
    }
    this.show = function(doclick) {
        this.elmt.className += ' ' + menuFocusClassName;
        if (doclick && this.onclickHandle != null) {
            this.onclickHandle();
        }
        
    }


    this.menu_onclick = function() {
        this.menuWrap.switchmenu(this,true);
        if(window.event)
        {
            window.event.cancelBubble = true;
            window.event.returnValue = false;
        }
    }

    this.hide();
    if (this.elmt.addEventListener)
        this.elmt.addEventListener('click', Evlon.createDelegate(this, this.menu_onclick), false);
    else if (this.elmt.attachEvent)
        this.elmt.attachEvent('onclick', Evlon.createDelegate(this, this.menu_onclick));
}


Evlon.MenuItemWrap = function(menuWnd, elmt, menuFocusClassName, elmtContent, menuItemFocusClassName) {
    this.menuWnd = menuWnd;
    this.elmt = elmt;
    this.menuFocusClassName = menuFocusClassName;
    this.menuItemFocusClassName = menuItemFocusClassName;
    this.content = elmtContent;
    this.subMenuItems = [];
    this.menuWnd.currentMenuItem = null;

    this.switchmenu = function(newmenu, doclick) {
        if (this.menuWnd.currentMenuItem  != newmenu) {

            if (this.menuWnd.currentMenuItem  != null)
                this.menuWnd.currentMenuItem.hide();
            this.menuWnd.currentMenuItem  = newmenu;
            this.menuWnd.currentMenuItem.show(doclick);
        }
        
    }


    this.isHide = function()
    {
        return this.content.style.display == 'none';
    }

    this.hide = function() {
        var re = new RegExp("\\s+" + menuFocusClassName, "ig");
        var className = ' ' + this.elmt.className.toString();
        this.elmt.className = className.replace(re, '');
        this.content.style.display = 'none';
        if(this.menuWnd.currentMenuItem != null)
                this.menuWnd.currentMenuItem.hide();
    }
    this.show = function(defaultItemIndex) {
        if(this.isHide())
        {
            this.elmt.className += ' ' + menuFocusClassName;
            this.content.style.display = '';
            
            if(defaultItemIndex == null)
            {
                // 加载配置
                var itemIndex = this.getItemIndex();
                if(typeof(this.menuWnd.profile[itemIndex]) == 'number')
                {
                    defaultItemIndex = this.menuWnd.profile[itemIndex];
                }
                    
            }

            if(defaultItemIndex!= null && defaultItemIndex >= 0 &&  defaultItemIndex < this.subMenuItems.length)
            {
                this.switchmenu(this.subMenuItems[defaultItemIndex],true);
            }
            else if(this.menuWnd.currentMenuItem != null)
            {
                this.menuWnd.currentMenuItem.show(false);
            }
        }
    }
    
    
    this.toggle = function()
    {
        if(this.isHide())
        {
            this.show();
        }
        else
        {
            this.hide();
        }
    }
    
    this.menu_onclick = function() {
        this.menuWnd.switchmenu(this,null,false);
        if(window.event)
        {
            window.event.cancelBubble = true;
            window.event.returnValue = false;
        }
    }
    
    

    this.hide();

     if (this.elmt.addEventListener)
        this.elmt.addEventListener('click', Evlon.createDelegate(this, this.menu_onclick), false);
    else if (this.elmt.attachEvent)
        this.elmt.attachEvent('onclick', Evlon.createDelegate(this, this.menu_onclick));
        
     if (this.content.addEventListener)
        this.content.addEventListener('click', function(){
                if(window.event)
                {
                    window.event.cancelBubble = true;
                    window.event.returnValue = false;
                }
            },false
        );
    else if (this.content.attachEvent)
        this.content.attachEvent('onclick', function(){
                if(window.event)
                {
                    window.event.cancelBubble = true;
                    window.event.returnValue = false;
                }
            }
        );

    var subMenus = Evlon.getChildren(this.content, { tagName: "LI" })
    for (var i = 0; i < subMenus.length; ++i) {
        var subMenu = subMenus[i];
        this.subMenuItems.push(new Evlon.MenuItem(this, subMenu, menuItemFocusClassName));
    }
    
    this.getItemIndex = function()
    {
        for(var i = 0; i < this.menuWnd.menus.length; ++i)
        {
            if(this.menuWnd.menus[i] == this)
            return i;
        }
        
        return -1;
    }


}

Evlon.QQMenu = function(idMenu, menuFocusClassName, menuItemFocusClassName, defaultMenuIndex, defaultItemIndex, profile /*[{main:0,item:0},{main:1,item:0}]*/) {
    this._menu = (typeof (idMenu) == 'string') ? document.getElementById(idMenu) : idMenu;
    this.menus = [];
    this.currentMenu = null;
    this.currentMenuItem = null;
    this.profile = {};  /* {menuIndex: itemIndex}*/

    this.switchmenu = function(newmenu, defaultItemIndex) {
        if (this.currentMenu != newmenu) {
            if (this.currentMenu != null)
                this.currentMenu.hide();
            this.currentMenu = newmenu;
            this.currentMenu.show(defaultItemIndex);
        }
        else {
            this.currentMenu.toggle();
        }
    }


    var childrens = Evlon.getChildren(this._menu, { tagName: 'LI' }); //.childNodes;
    if (childrens.length > 0) {
        for (var i = 0; i < childrens.length; ++i) {
            var li = childrens[i];
            var contents = Evlon.getChildren(li, { tagName: 'UL' });
            if (contents.length != 1)
                throw '必须只有一个子UL标签';

            this.menus.push(new Evlon.MenuItemWrap(this, li, menuFocusClassName, contents[0], menuItemFocusClassName));
        }
        
        //变换配置
        if(typeof(profile) == 'object')
        {
            for(var i = 0; i < profile.length; ++i)
            {
                this.profile[profile[i].main] = profile[i].item;
            }
        }

        this.switchmenu(this.menus[defaultMenuIndex],defaultItemIndex);
    }
}

<ul id="menu" class="menu">
    <li>分组一
     <ul>
              <li onclick="javascript:void(0);">菜单一</li>
              <li onclick="javascript:void(0);">菜单二</li>
          </ul>
    </li>
    <li>分组二
     <ul>
              <li onclick="javascript:void(0);">菜单一</li>
              <li onclick="javascript:void(0);">菜单二</li>
          </ul>
    </li>
    <li>分组三
     <ul>
              <li onclick="javascript:void(0);">菜单一</li>
              <li onclick="javascript:void(0);">菜单二</li>
          </ul>
    </li>
</ul>

<script  type="text/javascript>
    var menu = new Evlon.QQMenu('menu' /*ul 的ID*/, 'menuhilight' /*分组高这样式 */ , 'hilight' /*菜单项高亮样式*/, def.main /*默认打开分组*/, def.item /*默认执行菜单项*/,[{main:0,item:0},{main:1,item:0}] /* 单击分组时，自动单击菜单项配置*/);
</script>

https://files.cnblogs.com/evlon/EvlonQQMenu.js