flot/source/jquery.colorhelpers.js

/* Plugin for jQuery for working with colors.
 *
 * Version 1.1.
 *
 * Inspiration from jQuery color animation plugin by John Resig.
 *
 * Released under the MIT license by Ole Laursen, October 2009.
 *
 * Examples:
 *
 *   $.color.parse("#fff").scale('rgb', 0.25).add('a', -0.5).toString()
 *   var c = $.color.extract($("#mydiv"), 'background-color');
 *   console.log(c.r, c.g, c.b, c.a);
 *   $.color.make(100, 50, 25, 0.4).toString() // returns "rgba(100,50,25,0.4)"
 *
 * Note that .scale() and .add() return the same modified object
 * instead of making a new one.
 *
 * V. 1.1: Fix error handling so e.g. parsing an empty string does
 * produce a color rather than just crashing.
 */

(function($) {
    $.color = {};

    // construct color object with some convenient chainable helpers
    $.color.make = function (r, g, b, a) {
        var o = {};
        o.r = r || 0;
        o.g = g || 0;
        o.b = b || 0;
        o.a = a != null ? a : 1;

        o.add = function (c, d) {
            for (var i = 0; i < c.length; ++i) {
                o[c.charAt(i)] += d;
            }

            return o.normalize();
        };

        o.scale = function (c, f) {
            for (var i = 0; i < c.length; ++i) {
                o[c.charAt(i)] *= f;
            }

            return o.normalize();
        };

        o.toString = function () {
            if (o.a >= 1.0) {
                return "rgb(" + [o.r, o.g, o.b].join(",") + ")";
            } else {
                return "rgba(" + [o.r, o.g, o.b, o.a].join(",") + ")";
            }
        };

        o.normalize = function () {
            function clamp(min, value, max) {
                return value < min ? min : (value > max ? max : value);
            }

            o.r = clamp(0, parseInt(o.r), 255);
            o.g = clamp(0, parseInt(o.g), 255);
            o.b = clamp(0, parseInt(o.b), 255);
            o.a = clamp(0, o.a, 1);
            return o;
        };

        o.clone = function () {
            return $.color.make(o.r, o.b, o.g, o.a);
        };

        return o.normalize();
    }

    // extract CSS color property from element, going up in the DOM
    // if it's "transparent"
    $.color.extract = function (elem, css) {
        var c;

        do {
            c = elem.css(css).toLowerCase();
            // keep going until we find an element that has color, or
            // we hit the body or root (have no parent)
            if (c !== '' && c !== 'transparent') {
                break;
            }

            elem = elem.parent();
        } while (elem.length && !$.nodeName(elem.get(0), "body"));

        // catch Safari's way of signalling transparent
        if (c === "rgba(0, 0, 0, 0)") {
            c = "transparent";
        }

        return $.color.parse(c);
    }

    // parse CSS color string (like "rgb(10, 32, 43)" or "#fff"),
    // returns color object, if parsing failed, you get black (0, 0,
    // 0) out
    $.color.parse = function (str) {
        var res, m = $.color.make;

        // Look for rgb(num,num,num)
        res = /rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(str);
        if (res) {
            return m(parseInt(res[1], 10), parseInt(res[2], 10), parseInt(res[3], 10));
        }

        // Look for rgba(num,num,num,num)
        res = /rgba\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str)
        if (res) {
            return m(parseInt(res[1], 10), parseInt(res[2], 10), parseInt(res[3], 10), parseFloat(res[4]));
        }

        // Look for rgb(num%,num%,num%)
        res = /rgb\(\s*([0-9]+(?:\.[0-9]+)?)%\s*,\s*([0-9]+(?:\.[0-9]+)?)%\s*,\s*([0-9]+(?:\.[0-9]+)?)%\s*\)/.exec(str);
        if (res) {
            return m(parseFloat(res[1]) * 2.55, parseFloat(res[2]) * 2.55, parseFloat(res[3]) * 2.55);
        }

        // Look for rgba(num%,num%,num%,num)
        res = /rgba\(\s*([0-9]+(?:\.[0-9]+)?)%\s*,\s*([0-9]+(?:\.[0-9]+)?)%\s*,\s*([0-9]+(?:\.[0-9]+)?)%\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(str);
        if (res) {
            return m(parseFloat(res[1]) * 2.55, parseFloat(res[2]) * 2.55, parseFloat(res[3]) * 2.55, parseFloat(res[4]));
        }

        // Look for #a0b1c2
        res = /#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(str);
        if (res) {
            return m(parseInt(res[1], 16), parseInt(res[2], 16), parseInt(res[3], 16));
        }

        // Look for #fff
        res = /#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(str);
        if (res) {
            return m(parseInt(res[1] + res[1], 16), parseInt(res[2] + res[2], 16), parseInt(res[3] + res[3], 16));
        }

        // Otherwise, we're most likely dealing with a named color
        var name = $.trim(str).toLowerCase();
        if (name === "transparent") {
            return m(255, 255, 255, 0);
        } else {
            // default to black
            res = lookupColors[name] || [0, 0, 0];
            return m(res[0], res[1], res[2]);
        }
    }

    var lookupColors = {
        aqua: [0, 255, 255],
        azure: [240, 255, 255],
        beige: [245, 245, 220],
        black: [0, 0, 0],
        blue: [0, 0, 255],
        brown: [165, 42, 42],
        cyan: [0, 255, 255],
        darkblue: [0, 0, 139],
        darkcyan: [0, 139, 139],
        darkgrey: [169, 169, 169],
        darkgreen: [0, 100, 0],
        darkkhaki: [189, 183, 107],
        darkmagenta: [139, 0, 139],
        darkolivegreen: [85, 107, 47],
        darkorange: [255, 140, 0],
        darkorchid: [153, 50, 204],
        darkred: [139, 0, 0],
        darksalmon: [233, 150, 122],
        darkviolet: [148, 0, 211],
        fuchsia: [255, 0, 255],
        gold: [255, 215, 0],
        green: [0, 128, 0],
        indigo: [75, 0, 130],
        khaki: [240, 230, 140],
        lightblue: [173, 216, 230],
        lightcyan: [224, 255, 255],
        lightgreen: [144, 238, 144],
        lightgrey: [211, 211, 211],
        lightpink: [255, 182, 193],
        lightyellow: [255, 255, 224],
        lime: [0, 255, 0],
        magenta: [255, 0, 255],
        maroon: [128, 0, 0],
        navy: [0, 0, 128],
        olive: [128, 128, 0],
        orange: [255, 165, 0],
        pink: [255, 192, 203],
        purple: [128, 0, 128],
        violet: [128, 0, 128],
        red: [255, 0, 0],
        silver: [192, 192, 192],
        white: [255, 255, 255],
        yellow: [255, 255, 0]
    };
})(jQuery);