/*
moo.fx, simple effects library built with prototype.js (http://prototype.conio.net).
by valerio proietti (http://mad4milk.net) mit-style license.
for more info (http://moofx.mad4milk.net).
sunday, march 05, 2006
v 1.2.3
*/

var fx = new object();
//base
fx.base = function(){};
fx.base.prototype = {
	setoptions: function(options) {
	this.options = {
		duration: 500,
		oncomplete: '',
		transition: fx.sinoidal
	}
	object.extend(this.options, options || {});
	},

	step: function() {
		var time  = (new date).gettime();
		if (time >= this.options.duration+this.starttime) {
			this.now = this.to;
			clearinterval (this.timer);
			this.timer = null;
			if (this.options.oncomplete) settimeout(this.options.oncomplete.bind(this), 10);
		}
		else {
			var tpos = (time - this.starttime) / (this.options.duration);
			this.now = this.options.transition(tpos) * (this.to-this.from) + this.from;
		}
		this.increase();
	},

	custom: function(from, to) {
		if (this.timer != null) return;
		this.from = from;
		this.to = to;
		this.starttime = (new date).gettime();
		this.timer = setinterval (this.step.bind(this), 13);
	},

	hide: function() {
		this.now = 0;
		this.increase();
	},

	cleartimer: function() {
		clearinterval(this.timer);
		this.timer = null;
	}
}

//stretchers
fx.layout = class.create();
fx.layout.prototype = object.extend(new fx.base(), {
	initialize: function(el, options) {
		this.el = $(el);
		this.el.style.overflow = "hidden";
		this.iniwidth = this.el.offsetwidth;
		this.iniheight = this.el.offsetheight;
		this.setoptions(options);
	}
});

fx.height = class.create();
object.extend(object.extend(fx.height.prototype, fx.layout.prototype), {	
	increase: function() {
		this.el.style.height = this.now + "px";
	},

	toggle: function() {
		if (this.el.offsetheight > 0) this.custom(this.el.offsetheight, 0);
		else this.custom(0, this.el.scrollheight);
	}
});

fx.width = class.create();
object.extend(object.extend(fx.width.prototype, fx.layout.prototype), {	
	increase: function() {
		this.el.style.width = this.now + "px";
	},

	toggle: function(){
		if (this.el.offsetwidth > 0) this.custom(this.el.offsetwidth, 0);
		else this.custom(0, this.iniwidth);
	}
});

//fader
fx.opacity = class.create();
fx.opacity.prototype = object.extend(new fx.base(), {
	initialize: function(el, options) {
		this.el = $(el);
		this.now = 1;
		this.increase();
		this.setoptions(options);
	},

	increase: function() {
		if (this.now == 1 && (/firefox/.test(navigator.useragent))) this.now = 0.9999;
		this.setopacity(this.now);
	},
	
	setopacity: function(opacity) {
		if (opacity == 0 && this.el.style.visibility != "hidden") this.el.style.visibility = "hidden";
		else if (this.el.style.visibility != "visible") this.el.style.visibility = "visible";
		if (window.activexobject) this.el.style.filter = "alpha(opacity=" + opacity*100 + ")";
		this.el.style.opacity = opacity;
	},

	toggle: function() {
		if (this.now > 0) this.custom(1, 0);
		else this.custom(0, 1);
	}
});

//transitions
fx.sinoidal = function(pos){
	return ((-math.cos(pos*math.pi)/2) + 0.5);
	//this transition is from script.aculo.us
}
fx.linear = function(pos){
	return pos;
}
fx.cubic = function(pos){
	return math.pow(pos, 3);
}
fx.circ = function(pos){
	return math.sqrt(pos);
}