mirror of
https://github.com/markqvist/Sideband.git
synced 2024-12-30 09:56:11 -05:00
91 lines
2.9 KiB
Python
91 lines
2.9 KiB
Python
|
"""
|
||
|
|
Theming Dynamic Text
|
||
|
|
====================
|
||
|
|
|
||
|
|
Two implementations. The first is based on color brightness obtained from-
|
||
|
|
https://www.w3.org/TR/AERT#color-contrast
|
||
|
|
The second is based on relative luminance calculation for sRGB obtained from-
|
||
|
|
https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
|
||
|
|
and contrast ratio calculation obtained from-
|
||
|
|
https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
|
||
|
|
|
||
|
|
Preliminary testing suggests color brightness more closely matches the
|
||
|
|
`Material Design spec` suggested text colors, but the alternative implementation
|
||
|
|
is both newer and the current 'correct' recommendation, so is included here
|
||
|
|
as an option.
|
||
|
|
"""
|
||
|
|
|
||
|
|
|
||
|
|
def _color_brightness(color):
|
||
|
|
# Implementation of color brightness method
|
||
|
|
brightness = color[0] * 299 + color[1] * 587 + color[2] * 114
|
||
|
|
brightness = brightness
|
||
|
|
return brightness
|
||
|
|
|
||
|
|
|
||
|
|
def _black_or_white_by_color_brightness(color):
|
||
|
|
if _color_brightness(color) >= 500:
|
||
|
|
return "black"
|
||
|
|
else:
|
||
|
|
return "white"
|
||
|
|
|
||
|
|
|
||
|
|
def _normalized_channel(color):
|
||
|
|
# Implementation of contrast ratio and relative luminance method
|
||
|
|
if color <= 0.03928:
|
||
|
|
return color / 12.92
|
||
|
|
else:
|
||
|
|
return ((color + 0.055) / 1.055) ** 2.4
|
||
|
|
|
||
|
|
|
||
|
|
def _luminance(color):
|
||
|
|
rg = _normalized_channel(color[0])
|
||
|
|
gg = _normalized_channel(color[1])
|
||
|
|
bg = _normalized_channel(color[2])
|
||
|
|
return 0.2126 * rg + 0.7152 * gg + 0.0722 * bg
|
||
|
|
|
||
|
|
|
||
|
|
def _black_or_white_by_contrast_ratio(color):
|
||
|
|
l_color = _luminance(color)
|
||
|
|
l_black = 0.0
|
||
|
|
l_white = 1.0
|
||
|
|
b_contrast = (l_color + 0.05) / (l_black + 0.05)
|
||
|
|
w_contrast = (l_white + 0.05) / (l_color + 0.05)
|
||
|
|
return "white" if w_contrast >= b_contrast else "black"
|
||
|
|
|
||
|
|
|
||
|
|
def get_contrast_text_color(color, use_color_brightness=True):
|
||
|
|
if use_color_brightness:
|
||
|
|
contrast_color = _black_or_white_by_color_brightness(color)
|
||
|
|
else:
|
||
|
|
contrast_color = _black_or_white_by_contrast_ratio(color)
|
||
|
|
if contrast_color == "white":
|
||
|
|
return 1, 1, 1, 1
|
||
|
|
else:
|
||
|
|
return 0, 0, 0, 1
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
from kivy.utils import get_color_from_hex
|
||
|
|
|
||
|
|
from kivymd.color_definitions import colors, text_colors
|
||
|
|
|
||
|
|
for c in colors.items():
|
||
|
|
if c[0] in ["Light", "Dark"]:
|
||
|
|
continue
|
||
|
|
color = c[0]
|
||
|
|
print(f"For the {color} color palette:")
|
||
|
|
for name, hex_color in c[1].items():
|
||
|
|
if hex_color:
|
||
|
|
col = get_color_from_hex(hex_color)
|
||
|
|
col_bri = get_contrast_text_color(col)
|
||
|
|
con_rat = get_contrast_text_color(
|
||
|
|
col, use_color_brightness=False
|
||
|
|
)
|
||
|
|
text_color = text_colors[c[0]][name]
|
||
|
|
print(
|
||
|
|
f" The {name} hue gives {col_bri} using color "
|
||
|
|
f"brightness, {con_rat} using contrast ratio, and "
|
||
|
|
f"{text_color} from the MD spec"
|
||
|
|
)
|