postcss-gtk/lib/color-functions.js

Processes GTK+ CSS into browser CSS

// Generated by CoffeeScript 1.9.1
(function() {
  var add_css_function, colorTransformers, convert, current_node, debug, fn, fn_name, lerp, parse, parseColor, rgba;

  parseColor = require("color-parser");

  convert = require("color-convert");

  add_css_function = require("./add-css-function");

  debug = function() {};

  current_node = null;

  parse = function(value) {
    var e, ref;
    try {
      return (function() {
        if ((ref = parseColor(value)) != null) {
          return ref;
        } else {
          throw new Error("Failed to parse color value " + value);
        }
      })();
    } catch (_error) {
      e = _error;
      if (current_node) {
        console.error(e.stack);
        throw current_node.error(e.message);
      } else {
        console.error("Error parsing color (with no associated CSS node)");
        throw e;
      }
    }
  };

  lerp = function(a, b, x) {
    return a + (b - a) * x;
  };

  rgba = function(r, g, b, a) {
    if (isNaN(a) || a === 1) {
      return "rgb(" + (~~r) + ", " + (~~g) + ", " + (~~b) + ")";
    } else {
      return "rgba(" + (~~r) + ", " + (~~g) + ", " + (~~b) + ", " + a + ")";
    }
  };

  colorTransformers = {
    mix: function(colorA, colorB, x) {
      var a, b, l;
      debug("MIX COLORS " + colorA + " AND " + colorB + " BY LERPY AMOUNT " + x);
      a = parse(colorA);
      b = parse(colorB);
      debug("-", colorA, a);
      debug("-", colorB, b);
      debug("-", x);
      l = function(p) {
        return lerp(a[p], b[p], x);
      };
      return rgba(l("r"), l("g"), l("b"), l("a"));
    },
    shade: function(color, value) {
      var a, b, g, h, l, r, ref, ref1, ref2, ref3, s;
      if (isNaN(value)) {
        ref = [value, color], color = ref[0], value = ref[1];
      }
      debug("SHADE COLOR " + color + " BY VALUE " + value);
      ref1 = parse(color), r = ref1.r, g = ref1.g, b = ref1.b, a = ref1.a;
      ref2 = convert.rgb2hslRaw(r, g, b), h = ref2[0], s = ref2[1], l = ref2[2];
      debug("- OLD LIGHTNESS: " + l);
      l *= value;
      debug("- NEW LIGHTNESS: " + l + " (AFTER APPLYING " + value + ")");
      ref3 = convert.hsl2rgb(h, s, l), r = ref3[0], g = ref3[1], b = ref3[2];
      return rgba(r, g, b, a);
    },
    alpha: function(color, factor) {
      var a, b, g, r, ref, ref1;
      if (isNaN(factor)) {
        ref = [factor, color], color = ref[0], factor = ref[1];
      }
      debug("MULTIPLY ALPHA OF COLOR " + color + " BY FACTOR " + factor);
      ref1 = parse(color), r = ref1.r, g = ref1.g, b = ref1.b, a = ref1.a;
      debug("- OLD", rgba(r, g, b, a));
      a *= factor;
      debug("- NEW", rgba(r, g, b, a));
      return rgba(r, g, b, a);
    }
  };

  for (fn_name in colorTransformers) {
    fn = colorTransformers[fn_name];
    add_css_function(fn_name, fn);
  }

}).call(this);