Source code for silx.gui.plot.Colors

# coding: utf-8
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"""Color conversion function and dictionary."""

__authors__ = ["V.A. Sole", "T. VINCENT"]
__license__ = "MIT"
__date__ = "22/02/2016"


import numpy


COLORDICT = {}
"""Dictionary of common colors."""

COLORDICT['b'] = COLORDICT['blue'] = '#0000ff'
COLORDICT['r'] = COLORDICT['red'] = '#ff0000'
COLORDICT['g'] = COLORDICT['green'] = '#00ff00'
COLORDICT['k'] = COLORDICT['black'] = '#000000'
COLORDICT['white'] = '#ffffff'
COLORDICT['pink'] = '#ff66ff'
COLORDICT['brown'] = '#a52a2a'
COLORDICT['orange'] = '#ff9900'
COLORDICT['violet'] = '#6600ff'
COLORDICT['gray'] = COLORDICT['grey'] = '#a0a0a4'
# COLORDICT['darkGray'] = COLORDICT['darkGrey'] = '#808080'
# COLORDICT['lightGray'] = COLORDICT['lightGrey'] = '#c0c0c0'
COLORDICT['y'] = COLORDICT['yellow'] = '#ffff00'
COLORDICT['m'] = COLORDICT['magenta'] = '#ff00ff'
COLORDICT['c'] = COLORDICT['cyan'] = '#00ffff'
COLORDICT['darkBlue'] = '#000080'
COLORDICT['darkRed'] = '#800000'
COLORDICT['darkGreen'] = '#008000'
COLORDICT['darkBrown'] = '#660000'
COLORDICT['darkCyan'] = '#008080'
COLORDICT['darkYellow'] = '#808000'
COLORDICT['darkMagenta'] = '#800080'


def rgba(color, colorDict=None):
    """Convert color code '#RRGGBB' and '#RRGGBBAA' to (R, G, B, A)

    :param str code: The color code to conver
    :param dict colorDict: A dictionary of color name conversion to color code
    :returns: RGBA colors as floats in [0., 1.]
    :rtype: tuple
    """
    if colorDict is None:
        colorDict = COLORDICT
    if len(color) == 4:
        r, g, b, a = color
        if type(color[3]) in [type(1), numpy.uint8, numpy.int8]:
            return r / 255., g / 255., b / 255., a / 255.
        if type(color[3]) in [type(1.), numpy.float32, numpy.float64]:
            assert r >= 0. and r <= 1.
            assert g >= 0. and g <= 1.
            assert b >= 0. and b <= 1.
            assert a >= 0. and a <= 1.
            return r, g, b, a

    # We assume color is a string
    if not color.startswith('#'):
        color = colorDict[color]

    assert len(color) in (7, 9) and color[0] == '#'
    r = int(color[1:3], 16) / 255.
    g = int(color[3:5], 16) / 255.
    b = int(color[5:7], 16) / 255.
    a = int(color[7:9], 16) / 255. if len(color) == 9 else 1.
    return r, g, b, a