// @name      The Fade Anything Technique
// @namespace http://www.axentric.com/aside/fat/
// @version   1.0-RC1
// @author    Adam Michela

var Fat = {

		make_hex : function (r,g,b) 
		{
			r = r.toString(16); if (r.length == 1) r = '0' + r;
			g = g.toString(16); if (g.length == 1) g = '0' + g;
			b = b.toString(16); if (b.length == 1) b = '0' + b;
			return "#" + r + g + b;
		},

		fade_all : function ()
		{
			var a = document.getElementsByTagName("*");
			for (var i = 0; i < a.length; i++) 
			{
				var o = a[i];
				var r = /fade-?(\w{3,6})?/.exec(o.className);
				if (r)
				{
					if (!r[1]) r[1] = "";
					if (o.id) Fat.fade_element(o.id,null,null,"#"+r[1]);
				}
			}
		},

		fade_element : function (id, fps, duration, from, to) 
		{
			if (!fps) fps = 30;
			if (!duration) duration = 1500;
			if (!from || from=="#") from = "#FFFF33";
			if (!to) to = this.get_bgcolor(id);

			var frames = Math.round(fps * (duration / 1000));
			var interval = duration / frames;
			var delay = interval;
			var frame = 0;

			if (from.length < 7) from += from.substr(1,3);
			if (to.length < 7) to += to.substr(1,3);

			var rf = parseInt(from.substr(1,2),16);
			var gf = parseInt(from.substr(3,2),16);
			var bf = parseInt(from.substr(5,2),16);
			var rt = parseInt(to.substr(1,2),16);
			var gt = parseInt(to.substr(3,2),16);
			var bt = parseInt(to.substr(5,2),16);

			var r,g,b,h;
			while (frame < frames)
			{
				r = Math.floor(rf * ((frames-frame)/frames) + rt * (frame/frames));
				g = Math.floor(gf * ((frames-frame)/frames) + gt * (frame/frames));
				b = Math.floor(bf * ((frames-frame)/frames) + bt * (frame/frames));
				h = this.make_hex(r,g,b);
				setTimeout("Fat.set_bgcolor('"+id+"','"+h+"')", delay);

				frame++;
				delay = interval * frame; 
			}
			setTimeout("Fat.set_bgcolor('"+id+"','"+to+"')", delay);
		},

		set_bgcolor : function (id, c)
		{
			var o = document.getElementById(id);
			o.style.backgroundColor = c;
		},

		get_bgcolor : function (id)
		{
			var o = document.getElementById(id);
			while(o)
			{
				var c;
				if (window.getComputedStyle) c = window.getComputedStyle(o,null).getPropertyValue("background-color");
				if (o.currentStyle) c = o.currentStyle.backgroundColor;
				if ((c != "" && c != "transparent") || o.tagName == "BODY") { break; }
				o = o.parentNode;
			}
			if (c == undefined || c == "" || c == "transparent") c = "#FFFFFF";
			var rgb = c.match(/rgb\s*\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})\s*\)/);
			if (rgb) c = this.make_hex(parseInt(rgb[1]),parseInt(rgb[2]),parseInt(rgb[3]));
			return c;
		}
	}