CSS JavaScript 实现菜单功能 改进版_导航菜单

if (document.getElementById){
var root = new Root();

var m1 = new Menu("File","alert(this.innerText);");
root.add(m1);
var m11 = new MenuItem("New");
m1.add(m11);
m1.add(new MenuItem("Open","alert('open file');"));
var m12 = new MenuItem("Save");
m1.add(m12);
m1.add(new MenuItem("Save As"));
m1.add(new MenuItem("Close"));
m1.add(new MenuItem(""));

var m2 = new Menu("Edit");
root.add(m2);

root.toString();
}

#menubar {
font-family:verdana;
font-size:12px;
margin:1px;
}
#menubar li {
float:left;
position:relative;
text-align:left;
}
/* each menu item style */
#menubar li a {
border-style:none;
color:black;
display:block;
width:150px;
height:20px;
line-height:20px;
padding-left:10px;
text-decoration:none;
}
/* the first level menu which displays default */
#menubar .menuMain{
border-color:#C0C0C0;
border-width:1px;
border-style:solid;
}
/* the first leve style when mouse on it */
#menubar li a:hover{
background-color:#efefef;
text-decoration:underline;
}
/* the second level menu block style */
#menubar li ul{
background-color:#efefef;
border-style:none;
display:none;
position:absolute;
top:20px;
left:-40px;
margin-top:2px;
width:150px;
}
/* the sub menu item style when mouse on it */
#menubar li ul li a:hover {
text-decoration:underline;
padding-left:20px;
}
/* the third or more level menu block style */
#menubar li ul li ul {
display:none;
position:absolute;
top:0px;
left:150px;
margin-top:0;
margin-left:0;
width:150px;
}

var MenuConfig = {
defaultText : "Menu Item",
defaultAction : "javascript:void(0);" ,
defaultMenuCssStyle : "menuMain"
};

var MenuHandler = {
idCounter : 0,
idPrefix : "menu-",
getId : function(){ return this.idPrefix + this.idCounter++ ;},
insertHTMLBeforeEnd : function(node, sHTML){
if(node.insertAdjacentHTML != null){
node.insertAdjacentHTML('BeforeEnd',sHTML);
return;
}
var df; // DocumentFragment
var r = node.ownerDocument.createRange();
r.selectNodeContents(node);
r.collapse(false);
df = r.createContextualFragment(sHTML);
node.appendChild(df);
}
}

function displaySubMenu(li){
var subMenu = li.getElementsByTagName('ul')[0];
if(subMenu)
subMenu.style.display = 'block';
}

function hideSubMenu(li){
var subMenu = li.getElementsByTagName('ul')[0];
if(subMenu)
subMenu.style.display = 'none';
}


/******************************************
* Funciont Name: MenuAbstractNode
* Description： MenuAbstractNode class
* @param {String} pText
* @param {String} pAction
* @Return：
*******************************************/
function MenuAbstractNode(pText, pAction){
this.text = pText || MenuConfig.defaultText;
this.action = pAction || MenuConfig.defaultAction;
this.id = MenuHandler.getId();

this.childNodes = [];
}

MenuAbstractNode.prototype.add = function(node){
this.childNodes[this.childNodes.length] = node;
}

/******************************************
* Funciont Name: toString
* Description： generate HTML code
* @param
* @param
* @Return：
*******************************************/
MenuAbstractNode.prototype.toString = function(){
var str = "

if(this.type=="Menu"){
str = str + " class=\"" + this.cssStyle + "\"";
}
str = str + " onclick=\""+this.action+"\">"+this.text+"";

var sb = [];

for (var i = 0; i sb[i] = this.childNodes[i].toString();
}
if(sb.length>0){
str = str + "

" + sb.join("") + "

"
}

return str + "

" ;
}

/******************************************
* Funciont Name: Menu
* Description： Menu class
* @param {String} pText
* @param {String} pAction
* @param {String} pCssStyle
* @Return：
*******************************************/
function Menu(pText, pAction,pCssStyle){
this.base = MenuAbstractNode;
this.base(pText,pAction);

this.type = "Menu";
this.cssStyle = pCssStyle || MenuConfig.defaultMenuCssStyle;
}

Menu.prototype = new MenuAbstractNode;

/******************************************
* Funciont Name: MenuItem
* Description： MenuItem class
* @param {String} pText
* @param {String} pAction
* @Return：
*******************************************/
function MenuItem(pText, pAction){
this.base = MenuAbstractNode;
this.base(pText,pAction);
this.type = "MenuItem";
}

MenuItem.prototype = new MenuAbstractNode;


/******************************************
* Funciont Name: Root
* Description： Root class
* @Return：
*******************************************/
function Root(){
this.id = "menubar";
this.childNodes=[];
}

Root.prototype = new MenuAbstractNode;

Root.prototype.toString = function(){
document.write("");
for(var i=0; iMenuHandler.insertHTMLBeforeEnd(document.getElementById(root.id), this.childNodes[i].toString());
}
}

if (document.getElementById){
var root = new Root();

var m1 = new Menu("File","alert(this.innerText);");
root.add(m1);
var m11 = new MenuItem("New","alert(this.innerText);");
m1.add(m11);
m1.add(new MenuItem("Open","alert('open file');"));
var m12 = new MenuItem("Save");
m1.add(m12);
m1.add(new MenuItem("Save As"));
m1.add(new MenuItem("Close"));
m1.add(new MenuItem(""));

var m2 = new Menu("Edit");
root.add(m2);
var m22 = new MenuItem("Select All");
m2.add(m22);
m2.add(new MenuItem("Cut"));
m2.add(new MenuItem("Copy"));
m2.add(new MenuItem("paste"));

var m3 = new Menu("View");
var m33 = new MenuItem("View List");
m33.add(new MenuItem("Function List"));
m3.add(m33);
m3.add(new MenuItem("Tool Bar"));
root.add(m3);
root.toString();
}