/*
Author: mg12
Update: 2008/09/06
Author URI: http://www.fighton.cn/
*/

var Class = {
	create: function() {
		return function() {
			this.initialize.apply(this, arguments);
		}
	}
}

var GhostlyMenu = Class.create();
GhostlyMenu.prototype = {

	initialize: function(target, align, opacity) {
		this.util = new MenuUtil();

		this.obj = this.util.cleanWhitespace(target);
		this.align = align || 'left';
		this.opacity = 0;
		this.maxopacity = opacity || 1;

		this.menu = this.obj.childNodes
		if (this.menu.length < 2) { return; }

		this.title = this.menu[0];
		this.body = this.menu[1];

		this.util.setStyle(this.body, 'visibility', 'hidden');
		this.util.setStyle(this.body, 'position', 'absolute');
		this.util.setStyle(this.body, 'overflow', 'hidden');
		this.util.setStyle(this.body, 'display', 'block');

		this.addListener(this.obj, 'mouseover', this.util.bind(this, this.activate), false);
		this.addListener(this.obj, 'mouseout', this.util.bind(this, this.deactivate), false);
	},

	activate: function() {

		for(i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
			if(a.getAttribute("title") == "dbx4menu") {
				a.disabled = false;
			}
		}

		var pos = this.util.cumulativeOffset(this.title);
		var left = pos[0];
		if (this.align == 'right') {
			var offset = this.util.getWidth(this.title) - this.util.getWidth(this.body);
			left += offset;
		}
		var top = pos[1] + this.util.getHeight(this.title);

		this.util.setStyle(this.body, 'left', left + 'px');
		this.util.setStyle(this.body, 'top', top + 'px');
		this.util.setStyle(this.body, 'visibility', 'visible');
		this.util.setStyle(this.body, 'opacity', this.opacity);
		this.util.setStyle(this.body, 'filter', 'alpha(opacity=' + this.opacity * 100 + ')');

		if(this.tid) {
			clearTimeout(this.tid);
		}
		this.tid = setInterval(this.util.bind(this, this.appear), 30);
	},

	deactivate: function(){
		if(this.tid) {
			clearTimeout(this.tid);
		}
		this.tid = setInterval(this.util.bind(this, this.fade), 30);
	},

	appear: function() {
		this.opacity += 0.1;
		if(this.opacity >= this.maxopacity) {
			this.opacity = this.maxopacity;
			clearTimeout(this.tid);
		}
		this.util.setStyle(this.body, 'opacity', this.opacity);
		this.util.setStyle(this.body, 'filter', 'alpha(opacity=' + this.opacity * 100 + ')');
	},

	fade:function() {
		this.opacity -= 0.1;
		if(this.opacity <= 0) {
			this.opacity = 0;
			this.util.setStyle(this.body, 'visibility', 'hidden');
			clearTimeout(this.tid);

			for(i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
				if(a.getAttribute("title") == "dbx4menu") {
					a.disabled = true;
				}
			}

		}
		this.util.setStyle(this.body, 'opacity', this.opacity);
		this.util.setStyle(this.body, 'filter', 'alpha(opacity=' + this.opacity * 100 + ')');
	},

	addListener: function(element, name, observer, useCapture) {
		if(element.addEventListener) {
			element.addEventListener(name, observer, useCapture);
		} else if(element.attachEvent) {
			element.attachEvent('on' + name, observer);
		}
	}
}

var MenuUtil = Class.create();
MenuUtil.prototype = {
	initialize: function() {
	},

	$: function(id) {
		return document.getElementById(id);
	},

	$A: function(iterable) {
		if(!iterable) {
			return [];
		}
		if(iterable.toArray) {
			return iterable.toArray();
		} else {
			var results = [];
			for(var i = 0; i < iterable.length; i++) {
				results.push(iterable[i]);
			}
			return results;
		}
	},

	bind: function() {
		var array = this.$A(arguments);
		var func = array[array.length - 1];
		var _method = func, args = array, object = args.shift();
		return function() {
			return _method.apply(object, args.concat(array));
		}
	},

	getHeight: function(element) {
		return element.offsetHeight;
	},

	getWidth: function(element) {
		return element.offsetWidth;
	},

	setStyle: function(element, key, value) {
		element.style[key] = value;
	},

	getStyle: function(element, key) {
		return element.style[key];
	},

	cleanWhitespace: function(list) {
		var node = list.firstChild;
		while (node) {
			var nextNode = node.nextSibling;
			if(node.nodeType == 3 && !/\S/.test(node.nodeValue)) {
				list.removeChild(node);
			}
			node = nextNode;
		}
		return list;
	},

	cumulativeOffset: function(element) {
		var valueT = 0, valueL = 0;
		do {
			valueT += element.offsetTop  || 0;
			valueL += element.offsetLeft || 0;
			element = element.offsetParent;
		} while (element);
		return [valueL, valueT];
	}
}

function loadMenus() {
	var subscribe = document.getElementById('subscribe');
	new GhostlyMenu(subscribe, 'right', 0.9);
}
if (document.addEventListener) {
	document.addEventListener("DOMContentLoaded", loadMenus, false);

} else if (navigator.userAgent.indexOf('MSIE') > 0) {
	document.onreadystatechange = function() {
		if (document.readyState == 'loaded' || document.readyState == 'complete') {
			loadMenus();
		}
	}
} else {
	window.onload = function(e) {
		loadMenus();
	}
}