// @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 = 3000;
                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;
        }
}