Allow specifying a value of `none for the :opt:selection_foreground`` which will cause kitty to not change text color in selections

Fixes #1358

docs/changelog.rst

@@ -7,6 +7,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 0.13.4 [future]
 ---------------------
 
+- Allow specifying a value of ``none`` for the :opt:`selection_foreground``
+  which will cause kitty to not change text color in selections (:iss:`1358`)
+
 - icat kitten: Add support for displaying images at http(s) URLs (:iss:`1340`)
 
 - A new option :opt:`strip_trailing_spaces` to optionally remove trailing

kitty/cell_vertex.glsl

@@ -5,6 +5,7 @@
 #define REVERSE_SHIFT {REVERSE_SHIFT}
 #define STRIKE_SHIFT {STRIKE_SHIFT}
 #define DIM_SHIFT {DIM_SHIFT}
+#define USE_SELECTION_FG
 
 // Inputs {{{
 layout(std140) uniform CellRenderData {
@@ -171,8 +172,10 @@ void main() {
     foreground = color_to_vec(resolved_fg);
     float has_dim = float((text_attrs >> DIM_SHIFT) & ONE);
     effective_text_alpha = inactive_text_alpha * mix(1.0, dim_opacity, has_dim);
+#ifdef USE_SELECTION_FG
     // Selection
     foreground = choose_color(float(is_selected & ONE), color_to_vec(highlight_fg), foreground);
+#endif
     // Underline and strike through (rendered via sprites)
     float in_url = float((is_selected & TWO) >> 1);
     decoration_fg = choose_color(in_url, color_to_vec(url_color), to_color(colors[2], resolved_fg));

kitty/config_data.py

@@ -655,9 +655,16 @@ def tab_fade(x):
 How much to dim text that has the DIM/FAINT attribute set. One means no dimming and
 zero means fully dimmed (i.e. invisible).'''))
 
-o('selection_foreground', '#000000', option_type=to_color, long_text=_('''
-The foreground and background for text selected with the mouse'''))
-o('selection_background', '#FFFACD', option_type=to_color)
+
+def selection_foreground(x):
+    if x.lower() != 'none':
+        return to_color(x)
+
+
+o('selection_foreground', '#000000', option_type=selection_foreground, long_text=_('''
+The foreground for text selected with the mouse. A value of none means to leave the color unchanged.'''))
+o('selection_background', '#FFFACD', option_type=to_color, long_text=_('''
+The background for text selected with the mouse.'''))
 
 g('colors.table')
 o('color0', '#000000', long_text=_('black'), option_type=to_color)

kitty/main.py

@@ -122,6 +122,7 @@ def _run_app(opts, args):
     if not is_wayland and not is_macos:  # no window icons on wayland
         with open(logo_data_file, 'rb') as f:
             set_default_window_icon(f.read(), 256, 256)
+    load_shader_programs.use_selection_fg = opts.selection_foreground is not None
     with cached_values_for(run_app.cached_values_name) as cached_values:
         with startup_notification_handler(extra_callback=run_app.first_window_callback) as pre_show_callback:
             window_id = create_os_window(

kitty/window.py

@@ -79,6 +79,9 @@ def color_as_vec3(x):
         if semi_transparent:
             vv = vv.replace('#define NOT_TRANSPARENT', '#define TRANSPARENT')
             ff = ff.replace('#define NOT_TRANSPARENT', '#define TRANSPARENT')
+        if not load_shader_programs.use_selection_fg:
+            vv = vv.replace('#define USE_SELECTION_FG', '#define DONT_USE_SELECTION_FG')
+            ff = ff.replace('#define USE_SELECTION_FG', '#define DONT_USE_SELECTION_FG')
         compile_program(p, vv, ff)
     v, f = load_shaders('graphics')
     for which, p in {
@@ -90,14 +93,18 @@ def color_as_vec3(x):
     init_cell_program()
 
 
+load_shader_programs.use_selection_fg = True
+
+
 def setup_colors(screen, opts):
     screen.color_profile.update_ansi_color_table(build_ansi_color_table(opts))
     cursor_text_color = opts.cursor_text_color or (12, 12, 12)
     cursor_text_color_as_bg = 3 if opts.cursor_text_color is None else 1
+    sfg = (0, 0, 0) if opts.selection_foreground is None else opts.selection_foreground
     screen.color_profile.set_configured_colors(*map(color_as_int, (
         opts.foreground, opts.background, opts.cursor,
         cursor_text_color, (0, 0, cursor_text_color_as_bg),
-        opts.selection_foreground, opts.selection_background)
+        sfg, opts.selection_background)
     ))