// @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;
    }
}

window.onload = function() {
    Fat.fade_all();
}