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from . import color4
#: Supported color spaces.
COLOR_SPACES = color4.COLOR_SPACES | {'device-cmyk'}
#: Supported color schemes.
COLOR_SCHEMES = {'light', 'dark'}
#: XYZ values of the D50 white point, normalized to Y=1.
D50 = color4.D50
#: XYZ values of the D65 white point, normalized to Y=1.
D65 = color4.D65
class Color(color4.Color):
COLOR_SPACES = None
def parse_color(input, color_schemes=None):
"""Parse a color value as defined in CSS Color Level 5.
https://www.w3.org/TR/css-color-5/
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type color_schemes: :obj:`str` or :term:`iterable`
:param color_schemes: the ``'normal'`` string, or an iterable of color
schemes used to resolve the ``light-dark()`` function.
:returns:
* :obj:`None` if the input is not a valid color value.
(No exception is raised.)
* The string ``'currentcolor'`` for the ``currentcolor`` keyword
* A :class:`Color` object for every other values, including keywords.
"""
color = color4.parse_color(input)
if color:
return color
if color_schemes is None or color_schemes == 'normal':
color_scheme = 'light'
else:
for color_scheme in color_schemes:
if color_scheme in COLOR_SCHEMES:
break
else:
color_scheme = 'light'
if isinstance(input, str):
token = color4.parse_one_component_value(input, skip_comments=True)
else:
token = input
if token.type == 'function':
tokens = [
token for token in token.arguments
if token.type not in ('whitespace', 'comment')]
name = token.lower_name
alpha = []
if name == 'color':
space, *tokens = tokens
old_syntax = all(token == ',' for token in tokens[1::2])
if old_syntax:
tokens = tokens[::2]
else:
for index, token in enumerate(tokens):
if token == '/':
alpha = tokens[index + 1:]
tokens = tokens[:index]
break
if name == 'device-cmyk':
return _parse_device_cmyk(tokens, color4._parse_alpha(alpha), old_syntax)
elif name == 'color':
return _parse_color(space, tokens, color4._parse_alpha(alpha))
elif name == 'light-dark':
return _parse_light_dark(tokens, color_scheme)
else:
return
def _parse_device_cmyk(args, alpha, old_syntax):
"""Parse a list of CMYK channels.
If args is a list of 4 NUMBER or PERCENTAGE tokens, return
device-cmyk :class:`Color`. Otherwise, return None.
Input C, M, Y, K ranges are [0, 1], output are [0, 1].
"""
if old_syntax:
if color4._types(args) != {'number'}:
return
else:
if not color4._types(args) <= {'number', 'percentage'}:
return
if len(args) != 4:
return
cmyk = [
arg.value if arg.type == 'number' else
arg.value / 100 if arg.type == 'percentage' else None
for arg in args]
cmyk = [max(0., min(1., float(channel))) for channel in cmyk]
return Color('device-cmyk', cmyk, alpha)
def _parse_light_dark(args, color_scheme):
colors = []
for arg in args:
if color := parse_color(arg, color_scheme):
colors.append(color)
if len(colors) == 2:
if color_scheme == 'light':
return colors[0]
else:
return colors[1]
return
def _parse_color(space, args, alpha):
"""Parse a color space name list of coordinates.
Ranges are [0, 1].
"""
if not color4._types(args) <= {'number', 'percentage'}:
return
if space.type != 'ident' or not space.value.startswith('--'):
return
coordinates = [
arg.value if arg.type == 'number' else
arg.value / 100 if arg.type == 'percentage' else None
for arg in args]
return Color(space.value, coordinates, alpha)
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