colorvalidator.py

# This file is in the public domain. Peter O., 2012. http://upokecenter.dreamhosters.com
# Any copyright to this work is released to the Public Domain.  In case this is not possible, this work is also licensed under the Unlicense: https://unlicense.org/
#
#  This file converts between different representations of HTML and CSS colors.

import re, math

def clamp(a, min, max):
    if a < min:
        return min
    elif a > max:
        return max
    else:
        return a

def hls_to_rgb(hls):
    """Converts Hue/Lightness/Sat colors to Red/Green/Blue colors.
      "hls" is a 3-element array containing the hue (0-360), lightness (0-255)
      and saturation (0-255).
      Returns a 3-element array containing the red, green, and blue (each 0-255)."""
    hueval = hls[0] * 1.0  # [0-360)
    lum = hls[1] * 1.0  # [0-255]
    sat = hls[2] * 1.0  # [0-255]
    lum = clamp(lum, 0, 255)
    sat = clamp(sat, 0, 255)
    if sat == 0:
        return [lum, lum, lum]
    b = 0
    if lum <= 127.5:
        b = (lum * (255.0 + sat)) / 255.0
    else:
        b = lum * sat
        b = b / 255.0
        b = lum + sat - b
    a = (lum * 2) - b
    r = 0
    g = 0
    bl = 0
    if hueval < 0 or hueval >= 360:
        hueval = ((hueval % 360) + 360) % 360
    hue = hueval + 120
    if hue >= 360:
        hue -= 360
    if hue < 60:
        r = a + (b - a) * hue / 60
    elif hue < 180:
        r = b
    elif hue < 240:
        r = a + (b - a) * (240 - hue) / 60
    else:
        r = a
    hue = hueval
    if hue < 60:
        g = a + (b - a) * hue / 60
    elif hue < 180:
        g = b
    elif hue < 240:
        g = a + (b - a) * (240 - hue) / 60
    else:
        g = a
    hue = hueval - 120
    if hue < 0:
        hue += 360
    if hue < 60:
        bl = a + (b - a) * hue / 60
    elif hue < 180:
        bl = b
    elif hue < 240:
        bl = a + (b - a) * (240 - hue) / 60
    else:
        bl = a
    return [clamp(r, 0, 255), clamp(g, 0, 255), clamp(bl, 0, 255)]

def color_html_to_rgba(x):
    """Converts HTML colors to Red/Green/Blue colors.
   "color" is an HTML color or color name (ex. #223344, #234, or royalblue).
   All strings are treated as valid.
   Returns a 4-element array containing the red, green, blue, and alpha
   (each 0-255); the alpha is always 255."""
    arr = []
    if x is None or len(x) == 0:
        return [0, 0, 0, 255]
    x = x.lower()
    if "grey" in x:
        x = re.sub("grey", "gray", x)
        # support "grey" variants
    if x in __color_to_rgba_namedColors:
        return color_to_rgba(__color_to_rgba_namedColors[x])
    if x[0] == "#":
        i = 1
    else:
        i = 0
    while i < len(x):
        c = ord(x[i])
        hex = 0
        if c >= 0x30 and c <= 0x39:
            hex = c - 0x30
        if c >= 0x61 and c <= 0x66:
            hex = c - 0x61 + 10
        arr.append(hex)
        i += 1
    sublength = math.floor((len(arr) + 2) / 3)
    while len(arr) < sublength * 3:
        arr.append(0)
    currlength = sublength
    offset = 0
    while currlength > 2:
        if (
            arr[offset] == 0
            and arr[sublength + offset] == 0
            and arr[sublength * 2 + offset] == 0
        ):
            currlength -= 1
            offset += 1
        else:
            break
    return [
        arr[offset] * 16 + arr[offset + 1],
        arr[sublength + offset] * 16 + arr[sublength + offset + 1],
        arr[sublength * 2 + offset] * 16 + arr[sublength * 2 + offset + 1],
        255,
    ]

# Converts a representation of a color to its RGB form
# Returns a 4-item array containing the intensity of red,
# green, blue, and alpha (each from 0-255)
def color_to_rgba(x):
    """--- NOTE: Use this function to parse colors from alpha color picker controls:
     --- http://peteroupc.github.com/colorpicker/
    Converts HTML colors to Red/Green/Blue colors.
    "color" is a CSS color, HTML color, or color name, including
    RGBA and HSLA (ex. #223344 or #234 or royalblue or
    rgb(20,20,20) or rgba(20,30,40,0.5) or hsl(100,100%,50%)
    or hsla(100,100%,50%,0.5) ).
    Invalid strings result in a return value of nil.
    Returns a 4-element array containing the red, green, blue, and alpha
    (each 0-255)."""
    e = []
    if x is None:
        return None
    c = None
    m = re.match("^#([A-Fa-f0-9]{2})([A-Fa-f0-9]{2})([A-Fa-f0-9]{2})$", x)
    if m:
        return [int(m.group(1), 16), int(m.group(2), 16), int(m.group(3), 16), 255]
    m = re.match("^rgb\(\s*([\+\-]?\d+)\s*,\s*([\+\-]?\d+)\s*,\s*([\+\-]?\d+)\s*\)$", x)
    if m:
        r1 = clamp(int(m.group(1)), 0, 255)
        r2 = clamp(int(m.group(2)), 0, 255)
        r3 = clamp(int(m.group(3)), 0, 255)
        return [r1, r2, r3, 255]
    m = re.match(
        "^rgb\(\s*([\+\-]?\d+(?:\.\d+)?%)\s*,\s*([\+\-]?\d+(?:\.\d+)?%)\s*,\s*([\+\-]?\d+(?:\.\d+)?%)\s*\)$",
        x,
    )
    if m:
        r1 = clamp(float(m.group(1)), 0, 100) * 255.0 / 100.0
        r2 = clamp(float(m.group(2)), 0, 100) * 255.0 / 100.0
        r3 = clamp(float(m.group(3)), 0, 100) * 255.0 / 100.0
        return [r1, r2, r3, 255]
    m = re.match(
        "^rgba\(\s*([\+\-]?\d+)\s*,\s*([\+\-]?\d+)\s*,\s*([\+\-]?\d+)\s*,\s*([\+\-]?\d+(?:\.\d+)?)\s*\)$",
        x,
    )
    if m:
        r1 = clamp(int(m.group(1)), 0, 255)
        r2 = clamp(int(m.group(2)), 0, 255)
        r3 = clamp(int(m.group(3)), 0, 255)
        r4 = clamp(float(m.group(4)), 0, 1.0) * 255
        return [r1, r2, r3, r4]
    m = re.match(
        "^rgba\(\s*([\+\-]?\d+(?:\.\d+)?%)\s*,\s*([\+\-]?\d+(?:\.\d+)?%)\s*,\s*([\+\-]?\d+(?:\.\d+)?%)\s*,\s*([\+\-]?\d+(?:\.\d+)?)\s*\)$",
        x,
    )
    if m:
        r1 = clamp(float(m.group(1)), 0, 100) * 255.0 / 100.0
        r2 = clamp(float(m.group(2)), 0, 100) * 255.0 / 100.0
        r3 = clamp(float(m.group(3)), 0, 100) * 255.0 / 100.0
        r4 = clamp(float(m.group(4)), 0, 1.0) * 255
        return [r1, r2, r3, r4]
    m = re.match("^#([A-Fa-f0-9]{1})([A-Fa-f0-9]{1})([A-Fa-f0-9]{1})$", x)
    if m:
        a = int(m.group(1), 16)
        b = int(m.group(2), 16)
        c = int(m.group(3), 16)
        return [a + (a << 4), b + (b << 4), c + (c << 4), 255]
    m = re.match(
        "^hsl\(\s*([\+\-]?\d+(?:\.\d+)?)\s*,\s*([\+\-]?\d+(?:\.\d+)?)%\s*,\s*([\+\-]?\d+(?:\.\d+)?)%\s*\)$",
        x,
    )
    if m:
        r1 = float(m.group(1))
        if r1 < 0 or r1 >= 360:
            r1 = ((r1 % 360) + 360) % 360
        r2 = clamp(float(m.group(3)), 0, 100) * 255.0 / 100.0
        r3 = clamp(float(m.group(2)), 0, 100) * 255.0 / 100.0
        rgb = hls_to_rgb([r1, r2, r3])
        return [rgb[0], rgb[1], rgb[2], 255]
    m = re.match(
        "^hsla\(\s*([\+\-]?\d+(?:\.\d+)?)\s*,\s*([\+\-]?\d+(?:\.\d+)?)%\s*,\s*([\+\-]?\d+(?:\.\d+)?)%\s*,\s*([\+\-]?\d+(?:\.\d+)?)\s*\)$",
        x,
    )
    if m:
        r1 = float(m.group(1))
        if r1 < 0 or r1 >= 360:
            r1 = ((r1 % 360) + 360) % 360
        r2 = clamp(float(m.group(3)), 0, 100) * 255.0 / 100.0
        r3 = clamp(float(m.group(2)), 0, 100) * 255.0 / 100.0
        r4 = clamp(float(m.group(4)), 0, 1.0) * 255
        rgb = hls_to_rgb([r1, r2, r3])
        return [rgb[0], rgb[1], rgb[2], r4]
    else:
        x = x.lower()
        if "grey" in x:
            x = re.sub("grey", "gray", x)  # support "grey" variants
        if x in __color_to_rgba_namedColors:
            return color_to_rgba(__color_to_rgba_namedColors[x])
        if x == "transparent":
            return [0, 0, 0, 0]
        return None

def color_to_rgb(x):
    """--- NOTE: Use this function to parse colors from normal color picker controls:
   --- http://peteroupc.github.com/colorpicker/
   Converts HTML colors to Red/Green/Blue colors.
   "color" is a CSS color, HTML color, or color name, NOT including
   RGBA or HSLA (ex. #223344 or #234 or royalblue
   or rgb(20,20,20) or hsl(100,100%,50%)).
   Invalid strings result in a return value of nil.
   Returns a 4-element array containing the red, green, blue, and alpha
   (each 0-255); the alpha is always 255."""
    # don't include rgba or hsla
    if index(x, "rgba") == 0 or index(x, "hsla") == 0:
        return None
    rgba = color_to_rgba(x)
    if rgba is None or rgba[3] == 0:
        return None
    return array(rgba[0], rgba[1], rgba[2], 255)

# Converts a color to a string.
# 'x' is a 3- or 4-item array containing the intensity of red,
# green, and blue (each from 0-255), with optional alpha (0-255)
def rgb_to_color(x):
    # we should include the spaces
    """Converts an RGBA color to a string, either rgb(...) or rgba(...) as applicable.
   "rgb" must contain at least 3 elements: the red, green, and blue (each 0-255).
   It can optionally contain a fourth element representing the alpha (0-255).
  """
    if x is None:
        x = [0, 0, 0, 0]
    if (len(x) > 3 and (x[3] == 255 or x[3] == None)) or len(x) == 3:
        return (
            "rgb("
            + str(round(x[0]))
            + ", "
            + str(round(x[1]))
            + ", "
            + str(round(x[2]))
            + ")"
        )
    else:
        prec = round(x[3] / 255.0, 2)
        if prec == int(prec):
            prec = int(prec)
        return (
            "rgba("
            + str(round(x[0]))
            + ", "
            + str(round(x[1]))
            + ", "
            + str(round(x[2]))
            + ", "
            + str(prec)
            + ")"
        )

def rgb_to_color_display(rgb):
    """Converts an RGBA color to a string, (ex. #002233 or rgba(...) as applicable).
   "rgb" must contain at least 3 elements: the red, green, and blue (each 0-255).
   It can optionally contain a fourth element representing the alpha (0-255).
   """
    if rgb is None:
        rgb = [0, 0, 0, 0]
    if len(rgb) == 3 or (len(rgb) > 3 and (rgb[3] == None or rgb[3] == 255)):
        return rgb_to_color_html(rgb)
    else:
        return re.sub("\s+", "", rgb_to_color(rgb))

def rgb_to_color_html(r, g=None, b=None):
    """ Converts an RGBA color to an HTML color, (ex. #002233).
   "rgb" must contain at least 3 elements: the red, green, and blue (each 0-255).
   """
    if r != None and g == None and b == None:
        return "#" + (
            format(clamp(round(r[0]), 0, 255), "02x")
            + format(clamp(round(r[1]), 0, 255), "02x")
            + format(clamp(round(r[2]), 0, 255), "02x")
        )
    else:
        return "#" + (
            format(clamp(round(r), 0, 255), "02x")
            + format(clamp(round(g), 0, 255), "02x")
            + format(clamp(round(b), 0, 255), "02x")
        )
        return ret

def __color_to_rgba_setUpNamedColors():
    ncs = (
        "aliceblue,f0f8ff,antiquewhite,faebd7,aqua,00ffff,aquamarine,7fffd4,azure,f0ffff,beige,f5f5dc,bisque,ffe4c4,black,000000,blanchedalmond,ffebcd,blue,0000ff,"
        + "blueviolet,8a2be2,brown,a52a2a,burlywood,deb887,cadetblue,5f9ea0,chartreuse,7fff00,chocolate,d2691e,coral,ff7f50,cornflowerblue,6495ed,cornsilk,fff8dc,"
        + "crimson,dc143c,cyan,00ffff,darkblue,00008b,darkcyan,008b8b,darkgoldenrod,b8860b,darkgray,a9a9a9,darkgreen,006400,darkkhaki,bdb76b,darkmagenta,8b008b,"
        + "darkolivegreen,556b2f,darkorange,ff8c00,darkorchid,9932cc,darkred,8b0000,darksalmon,e9967a,darkseagreen,8fbc8f,darkslateblue,483d8b,darkslategray,2f4f4f,"
        + "darkturquoise,00ced1,darkviolet,9400d3,deeppink,ff1493,deepskyblue,00bfff,dimgray,696969,dodgerblue,1e90ff,firebrick,b22222,floralwhite,fffaf0,forestgreen,"
        + "228b22,fuchsia,ff00ff,gainsboro,dcdcdc,ghostwhite,f8f8ff,gold,ffd700,goldenrod,daa520,gray,808080,green,008000,greenyellow,adff2f,honeydew,f0fff0,hotpink,"
        + "ff69b4,indianred,cd5c5c,indigo,4b0082,ivory,fffff0,khaki,f0e68c,lavender,e6e6fa,lavenderblush,fff0f5,lawngreen,7cfc00,lemonchiffon,fffacd,lightblue,add8e6,"
        + "lightcoral,f08080,lightcyan,e0ffff,lightgoldenrodyellow,fafad2,lightgray,d3d3d3,lightgreen,90ee90,lightpink,ffb6c1,lightsalmon,ffa07a,lightseagreen,20b2aa,"
        + "lightskyblue,87cefa,lightslategray,778899,lightsteelblue,b0c4de,lightyellow,ffffe0,lime,00ff00,limegreen,32cd32,linen,faf0e6,magenta,ff00ff,maroon,800000,"
        + "mediumaquamarine,66cdaa,mediumblue,0000cd,mediumorchid,ba55d3,mediumpurple,9370d8,mediumseagreen,3cb371,mediumslateblue,7b68ee,mediumspringgreen,"
        + "00fa9a,mediumturquoise,48d1cc,mediumvioletred,c71585,midnightblue,191970,mintcream,f5fffa,mistyrose,ffe4e1,moccasin,ffe4b5,navajowhite,ffdead,navy,"
        + "000080,oldlace,fdf5e6,olive,808000,olivedrab,6b8e23,orange,ffa500,orangered,ff4500,orchid,da70d6,palegoldenrod,eee8aa,palegreen,98fb98,paleturquoise,"
        + "afeeee,palevioletred,d87093,papayawhip,ffefd5,peachpuff,ffdab9,peru,cd853f,pink,ffc0cb,plum,dda0dd,powderblue,b0e0e6,purple,800080,rebeccapurple,663399,red,ff0000,rosybrown,"
        + "bc8f8f,royalblue,4169e1,saddlebrown,8b4513,salmon,fa8072,sandybrown,f4a460,seagreen,2e8b57,seashell,fff5ee,sienna,a0522d,silver,c0c0c0,skyblue,87ceeb,"
        + "slateblue,6a5acd,slategray,708090,snow,fffafa,springgreen,00ff7f,steelblue,4682b4,tan,d2b48c,teal,008080,thistle,d8bfd8,tomato,ff6347,turquoise,40e0d0,violet,"
        + "ee82ee,wheat,f5deb3,white,ffffff,whitesmoke,f5f5f5,yellow,ffff00,yellowgreen,9acd32"
    )
    nc = ncs.split(",")
    __color_to_rgba_namedColors = {}
    i = 0
    while i < len(nc):
        __color_to_rgba_namedColors[nc[i]] = "#" + nc[i + 1]
        i += 2
    return __color_to_rgba_namedColors

__color_to_rgba_namedColors = __color_to_rgba_setUpNamedColors()