feat(preview: entry): correctly show border

oomox_gui/color.py

@@ -21,12 +21,16 @@ def color_hex_from_list(color_list):
  return ''.join([int_to_hex(i) for i in color_list])
 
 
-def is_dark(color_text):
+def hex_lightness(color_text):
  # @TODO: use real lightness from HSV or Lab color model
  return sum([
  hex_to_int(channel_text)
  for channel_text in color_list_from_hex(color_text)
- ]) < 384
+ ]) / 765
+
+
+def is_dark(color_text):
+ return hex_lightness(color_text) < 0.5
 
 
 def hex_darker(color_text, darken_amount=10):

oomox_gui/preview.py

@@ -4,7 +4,7 @@
 
 from .theme_model import THEME_MODEL
 from .color import (
- convert_theme_color_to_gdk, mix_theme_colors, mix_gdk_colors,
+ convert_theme_color_to_gdk, mix_theme_colors, mix_gdk_colors, hex_lightness,
 )
 from .gtk_helpers import ScaledImage
 from .preview_terminal import TerminalThemePreview
@@ -344,11 +344,13 @@ def update_preview_borders(self, colorscheme):
  ), (
  'entry',
  self.gtk_preview.entry,
- mix_theme_colors(
- colorscheme['TXT_FG'], colorscheme['TXT_BG'], 0.20
- ),
- colorscheme['BG'],
- 0.69
+ colorscheme['TXT_BG'],
+ colorscheme['TXT_FG'],
+ 0.8 * (0.7 + (
+ 0 if hex_lightness(colorscheme['TXT_BG']) > 0.66 else (
+ 0.1 if hex_lightness(colorscheme['TXT_BG']) > 0.33 else 0.3
+ )
+ ))
  ),
  ):
  border_color = mix_theme_colors(fg, bg, ratio)