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debian-python-tinycss2/tinycss2/color3.py

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from __future__ import division
import collections
import re
from ._compat import basestring
from .parser import parse_one_component_value
class RGBA(collections.namedtuple('RGBA', ['red', 'green', 'blue', 'alpha'])):
"""An RGBA color.
A tuple of four floats in the 0..1 range: ``(red, green, blue, alpha)``.
.. attribute:: red
Convenience access to the red channel. Same as ``rgba[0]``.
.. attribute:: green
Convenience access to the green channel. Same as ``rgba[1]``.
.. attribute:: blue
Convenience access to the blue channel. Same as ``rgba[2]``.
.. attribute:: alpha
Convenience access to the alpha channel. Same as ``rgba[3]``.
"""
def parse_color(input):
"""Parse a color value as defined in `CSS Color Level 3
<http://www.w3.org/TR/css3-color/>`_.
:param input:
A :term:`string`, or a single :term:`component value`.
:returns:
* :obj:`None` if the input is not a valid color value.
(No exception is raised.)
* The string ``'currentColor'`` for the *currentColor* keyword
* Or a :class:`RGBA` object for every other values
(including keywords, HSL and HSLA.)
The alpha channel is clipped to [0, 1]
but red, green, or blue can be out of range
(eg. ``rgb(-10%, 120%, 0%)`` is represented as
``(-0.1, 1.2, 0, 1)``.)
"""
if isinstance(input, basestring):
token = parse_one_component_value(input, skip_comments=True)
else:
token = input
if token.type == 'ident':
return _COLOR_KEYWORDS.get(token.lower_value)
elif token.type == 'hash':
for multiplier, regexp in _HASH_REGEXPS:
match = regexp(token.value)
if match:
r, g, b = [int(group * multiplier, 16) / 255
for group in match.groups()]
return RGBA(r, g, b, 1.)
elif token.type == 'function':
args = _parse_comma_separated(token.arguments)
if args:
name = token.lower_name
if name == 'rgb':
return _parse_rgb(args, alpha=1.)
elif name == 'rgba':
alpha = _parse_alpha(args[3:])
if alpha is not None:
return _parse_rgb(args[:3], alpha)
elif name == 'hsl':
return _parse_hsl(args, alpha=1.)
elif name == 'hsla':
alpha = _parse_alpha(args[3:])
if alpha is not None:
return _parse_hsl(args[:3], alpha)
def _parse_alpha(args):
"""
If args is a list of a single INTEGER or NUMBER token,
retur its value clipped to the 0..1 range
Otherwise, return None.
"""
if len(args) == 1 and args[0].type == 'number':
return min(1, max(0, args[0].value))
def _parse_rgb(args, alpha):
"""
If args is a list of 3 INTEGER tokens or 3 PERCENTAGE tokens,
return RGB values as a tuple of 3 floats in 0..1.
Otherwise, return None.
"""
types = [arg.type for arg in args]
if (types == ['number', 'number', 'number'] and
all(a.is_integer for a in args)):
r, g, b = [arg.int_value / 255 for arg in args[:3]]
return RGBA(r, g, b, alpha)
elif types == ['percentage', 'percentage', 'percentage']:
r, g, b = [arg.value / 100 for arg in args[:3]]
return RGBA(r, g, b, alpha)
def _parse_hsl(args, alpha):
"""
If args is a list of 1 INTEGER token and 2 PERCENTAGE tokens,
return RGB values as a tuple of 3 floats in 0..1.
Otherwise, return None.
"""
types = [arg.type for arg in args]
if types == ['number', 'percentage', 'percentage'] and args[0].is_integer:
r, g, b = _hsl_to_rgb(args[0].int_value, args[1].value, args[2].value)
return RGBA(r, g, b, alpha)
def _hsl_to_rgb(hue, saturation, lightness):
"""
:param hue: degrees
:param saturation: percentage
:param lightness: percentage
:returns: (r, g, b) as floats in the 0..1 range
"""
hue = (hue / 360) % 1
saturation = min(1, max(0, saturation / 100))
lightness = min(1, max(0, lightness / 100))
# Translated from ABC: http://www.w3.org/TR/css3-color/#hsl-color
def hue_to_rgb(m1, m2, h):
if h < 0:
h += 1
if h > 1:
h -= 1
if h * 6 < 1:
return m1 + (m2 - m1) * h * 6
if h * 2 < 1:
return m2
if h * 3 < 2:
return m1 + (m2 - m1) * (2 / 3 - h) * 6
return m1
if lightness <= 0.5:
m2 = lightness * (saturation + 1)
else:
m2 = lightness + saturation - lightness * saturation
m1 = lightness * 2 - m2
return (
hue_to_rgb(m1, m2, hue + 1 / 3),
hue_to_rgb(m1, m2, hue),
hue_to_rgb(m1, m2, hue - 1 / 3),
)
def _parse_comma_separated(tokens):
"""Parse a list of tokens (typically the content of a function token)
as arguments made of a single token each, separated by mandatory commas,
with optional white space around each argument.
return the argument list without commas or white space;
or None if the function token content do not match the description above.
"""
tokens = [token for token in tokens
if token.type not in ('whitespace', 'comment')]
if not tokens:
return []
if len(tokens) % 2 == 1 and all(token == ',' for token in tokens[1::2]):
return tokens[::2]
_HASH_REGEXPS = (
(2, re.compile('^([\da-f])([\da-f])([\da-f])$', re.I).match),
(1, re.compile('^([\da-f]{2})([\da-f]{2})([\da-f]{2})$', re.I).match),
)
# (r, g, b) in 0..255
_BASIC_COLOR_KEYWORDS = [
('black', (0, 0, 0)),
('silver', (192, 192, 192)),
('gray', (128, 128, 128)),
('white', (255, 255, 255)),
('maroon', (128, 0, 0)),
('red', (255, 0, 0)),
('purple', (128, 0, 128)),
('fuchsia', (255, 0, 255)),
('green', (0, 128, 0)),
('lime', (0, 255, 0)),
('olive', (128, 128, 0)),
('yellow', (255, 255, 0)),
('navy', (0, 0, 128)),
('blue', (0, 0, 255)),
('teal', (0, 128, 128)),
('aqua', (0, 255, 255)),
]
# (r, g, b) in 0..255
_EXTENDED_COLOR_KEYWORDS = [
('aliceblue', (240, 248, 255)),
('antiquewhite', (250, 235, 215)),
('aqua', (0, 255, 255)),
('aquamarine', (127, 255, 212)),
('azure', (240, 255, 255)),
('beige', (245, 245, 220)),
('bisque', (255, 228, 196)),
('black', (0, 0, 0)),
('blanchedalmond', (255, 235, 205)),
('blue', (0, 0, 255)),
('blueviolet', (138, 43, 226)),
('brown', (165, 42, 42)),
('burlywood', (222, 184, 135)),
('cadetblue', (95, 158, 160)),
('chartreuse', (127, 255, 0)),
('chocolate', (210, 105, 30)),
('coral', (255, 127, 80)),
('cornflowerblue', (100, 149, 237)),
('cornsilk', (255, 248, 220)),
('crimson', (220, 20, 60)),
('cyan', (0, 255, 255)),
('darkblue', (0, 0, 139)),
('darkcyan', (0, 139, 139)),
('darkgoldenrod', (184, 134, 11)),
('darkgray', (169, 169, 169)),
('darkgreen', (0, 100, 0)),
('darkgrey', (169, 169, 169)),
('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)),
('darkseagreen', (143, 188, 143)),
('darkslateblue', (72, 61, 139)),
('darkslategray', (47, 79, 79)),
('darkslategrey', (47, 79, 79)),
('darkturquoise', (0, 206, 209)),
('darkviolet', (148, 0, 211)),
('deeppink', (255, 20, 147)),
('deepskyblue', (0, 191, 255)),
('dimgray', (105, 105, 105)),
('dimgrey', (105, 105, 105)),
('dodgerblue', (30, 144, 255)),
('firebrick', (178, 34, 34)),
('floralwhite', (255, 250, 240)),
('forestgreen', (34, 139, 34)),
('fuchsia', (255, 0, 255)),
('gainsboro', (220, 220, 220)),
('ghostwhite', (248, 248, 255)),
('gold', (255, 215, 0)),
('goldenrod', (218, 165, 32)),
('gray', (128, 128, 128)),
('green', (0, 128, 0)),
('greenyellow', (173, 255, 47)),
('grey', (128, 128, 128)),
('honeydew', (240, 255, 240)),
('hotpink', (255, 105, 180)),
('indianred', (205, 92, 92)),
('indigo', (75, 0, 130)),
('ivory', (255, 255, 240)),
('khaki', (240, 230, 140)),
('lavender', (230, 230, 250)),
('lavenderblush', (255, 240, 245)),
('lawngreen', (124, 252, 0)),
('lemonchiffon', (255, 250, 205)),
('lightblue', (173, 216, 230)),
('lightcoral', (240, 128, 128)),
('lightcyan', (224, 255, 255)),
('lightgoldenrodyellow', (250, 250, 210)),
('lightgray', (211, 211, 211)),
('lightgreen', (144, 238, 144)),
('lightgrey', (211, 211, 211)),
('lightpink', (255, 182, 193)),
('lightsalmon', (255, 160, 122)),
('lightseagreen', (32, 178, 170)),
('lightskyblue', (135, 206, 250)),
('lightslategray', (119, 136, 153)),
('lightslategrey', (119, 136, 153)),
('lightsteelblue', (176, 196, 222)),
('lightyellow', (255, 255, 224)),
('lime', (0, 255, 0)),
('limegreen', (50, 205, 50)),
('linen', (250, 240, 230)),
('magenta', (255, 0, 255)),
('maroon', (128, 0, 0)),
('mediumaquamarine', (102, 205, 170)),
('mediumblue', (0, 0, 205)),
('mediumorchid', (186, 85, 211)),
('mediumpurple', (147, 112, 219)),
('mediumseagreen', (60, 179, 113)),
('mediumslateblue', (123, 104, 238)),
('mediumspringgreen', (0, 250, 154)),
('mediumturquoise', (72, 209, 204)),
('mediumvioletred', (199, 21, 133)),
('midnightblue', (25, 25, 112)),
('mintcream', (245, 255, 250)),
('mistyrose', (255, 228, 225)),
('moccasin', (255, 228, 181)),
('navajowhite', (255, 222, 173)),
('navy', (0, 0, 128)),
('oldlace', (253, 245, 230)),
('olive', (128, 128, 0)),
('olivedrab', (107, 142, 35)),
('orange', (255, 165, 0)),
('orangered', (255, 69, 0)),
('orchid', (218, 112, 214)),
('palegoldenrod', (238, 232, 170)),
('palegreen', (152, 251, 152)),
('paleturquoise', (175, 238, 238)),
('palevioletred', (219, 112, 147)),
('papayawhip', (255, 239, 213)),
('peachpuff', (255, 218, 185)),
('peru', (205, 133, 63)),
('pink', (255, 192, 203)),
('plum', (221, 160, 221)),
('powderblue', (176, 224, 230)),
('purple', (128, 0, 128)),
('red', (255, 0, 0)),
('rosybrown', (188, 143, 143)),
('royalblue', (65, 105, 225)),
('saddlebrown', (139, 69, 19)),
('salmon', (250, 128, 114)),
('sandybrown', (244, 164, 96)),
('seagreen', (46, 139, 87)),
('seashell', (255, 245, 238)),
('sienna', (160, 82, 45)),
('silver', (192, 192, 192)),
('skyblue', (135, 206, 235)),
('slateblue', (106, 90, 205)),
('slategray', (112, 128, 144)),
('slategrey', (112, 128, 144)),
('snow', (255, 250, 250)),
('springgreen', (0, 255, 127)),
('steelblue', (70, 130, 180)),
('tan', (210, 180, 140)),
('teal', (0, 128, 128)),
('thistle', (216, 191, 216)),
('tomato', (255, 99, 71)),
('turquoise', (64, 224, 208)),
('violet', (238, 130, 238)),
('wheat', (245, 222, 179)),
('white', (255, 255, 255)),
('whitesmoke', (245, 245, 245)),
('yellow', (255, 255, 0)),
('yellowgreen', (154, 205, 50)),
]
# (r, g, b, a) in 0..1 or a string marker
_SPECIAL_COLOR_KEYWORDS = {
'currentcolor': 'currentColor',
'transparent': RGBA(0., 0., 0., 0.),
}
# RGBA namedtuples of (r, g, b, a) in 0..1 or a string marker
_COLOR_KEYWORDS = _SPECIAL_COLOR_KEYWORDS.copy()
_COLOR_KEYWORDS.update(
# 255 maps to 1, 0 to 0, the rest is linear.
(keyword, RGBA(r / 255., g / 255., b / 255., 1.))
for keyword, (r, g, b) in _BASIC_COLOR_KEYWORDS + _EXTENDED_COLOR_KEYWORDS)
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