/**
* constructor of AY Menu
* @param id - used to be a DIV id
**/
function LeftBody(id) {
	if (!document.getElementById || !document.getElementsByTagName)
		return false;
		
	this.menu = document.getElementById(id);
	this.submenus = this.menu.getElementsByTagName("div");
	
	//will make browser remeber lastest menu state by write cookies
	//this.remember = true;    
	
	//indicate the expand speed
	this.speed = 4;

	//one menu item expand
	this.oneSmOnly = true;
}

/**
* init process of building the menu
**/
LeftBody.prototype.init = function() {
	var mainInstance = this;
	for (var i = 0; i < this.submenus.length; i++)
		this.submenus[i].getElementsByTagName("span")[0].onclick = function() {
			mainInstance.toggleMenu(this.parentNode);
		};
	
	/*
	if (this.remember) {
		var regex = new RegExp("sdmenu_" + encodeURIComponent(this.menu.id) + "=([01]+)");
		var match = regex.exec(document.cookie);
		if (match) {
			var states = match[1].split("");
			for (var i = 0; i < states.length; i++)
				this.submenus[i].className = (states[i] == 0 ? "collapsed" : "");
		}
	}*/
};

LeftBody.prototype.toggleMenu = function(submenu) {
	if (submenu.className == "gh_leftone")
		this.expandMenu(submenu);
	else
		this.collapseMenu(submenu);
};

LeftBody.prototype.expandMenu = function(submenu) {
	var fullHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var links = submenu.getElementsByTagName("a");
	for (var i = 0; i < links.length; i++)
		fullHeight += links[i].offsetHeight;
	var moveBy = Math.round(this.speed * links.length);
	
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight + moveBy;
		if (newHeight < fullHeight)
			submenu.style.height = newHeight + "px";
		else {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "";
			//mainInstance.memorize();
		}
	}, 30);
	this.collapseOthers(submenu);
};

LeftBody.prototype.collapseMenu = function(submenu) {
	var minHeight = submenu.getElementsByTagName("span")[0].offsetHeight;
	var moveBy = Math.round(this.speed * submenu.getElementsByTagName("a").length);
	var mainInstance = this;
	var intId = setInterval(function() {
		var curHeight = submenu.offsetHeight;
		var newHeight = curHeight - moveBy;
		if (newHeight > minHeight)
			submenu.style.height = newHeight + "px";
		else {
			clearInterval(intId);
			submenu.style.height = "";
			submenu.className = "collapsed";
			//mainInstance.memorize();
		}
	}, 30);
};

LeftBody.prototype.collapseOthers = function(submenu) {
	if (this.oneSmOnly) {
		for (var i = 0; i < this.submenus.length; i++)
			if (this.submenus[i] != submenu && this.submenus[i].className != "gh_leftone")
				this.collapseMenu(this.submenus[i]);
	}
};

/**
* expand all menu items
* we don't need this method
* ignore here
**/
LeftBody.prototype.expandAll = function() {
	var oldOneSmOnly = this.oneSmOnly;
	this.oneSmOnly = false;
	for (var i = 0; i < this.submenus.length; i++)
		if (this.submenus[i].className == "gh_leftone")
			this.expandMenu(this.submenus[i]);
	this.oneSmOnly = oldOneSmOnly;
};

/**
* close all menu items
* we don't need this method
* ignore here
**/
LeftBody.prototype.collapseAll = function() {
	for (var i = 0; i < this.submenus.length; i++)
		if (this.submenus[i].className != "gh_leftone")
			this.collapseMenu(this.submenus[i]);
};

/*
LeftBody.prototype.memorize = function() {
	if (this.remember) {
		var states = new Array();
		for (var i = 0; i < this.submenus.length; i++)
			states.push(this.submenus[i].className == "collapsed" ? 0 : 1);
		var d = new Date();
		d.setTime(d.getTime() + (30 * 24 * 60 * 60 * 1000));
		document.cookie = "sdmenu_" + encodeURIComponent(this.menu.id) + "=" + states.join("") + "; expires=" + d.toGMTString() + "; path=/";
	}
};*/