Merge branch 'st/dark-mode' into master

Improve dark mode support. Do not hard-code widget colors and instead
pull them from the current theme and update them in the options
database.

* st/dark-mode:
  git-gui: improve dark mode support

git-gui.sh

@@ -720,7 +720,9 @@ proc rmsel_tag {text} {
 		-background [$text cget -background] \
 		-foreground [$text cget -foreground] \
 		-borderwidth 0
-	$text tag conf in_sel -background lightgray
+	$text tag conf in_sel\
+		-background $color::select_bg \
+		-foreground $color::select_fg
 	bind $text <Motion> break
 	return $text
 }
@@ -863,6 +865,7 @@ proc apply_config {} {
 			set NS ttk
 			bind [winfo class .] <<ThemeChanged>> [list InitTheme]
 			pave_toplevel .
+			color::sync_with_theme
 		}
 	}
 }
@@ -3272,7 +3275,7 @@ pack .vpane -anchor n -side top -fill both -expand 1
 textframe .vpane.files.workdir -height 100 -width 200
 tlabel .vpane.files.workdir.title -text [mc "Unstaged Changes"] \
 	-background lightsalmon -foreground black
-ttext $ui_workdir -background white -foreground black \
+ttext $ui_workdir \
 	-borderwidth 0 \
 	-width 20 -height 10 \
 	-wrap none \
@@ -3294,7 +3297,7 @@ textframe .vpane.files.index -height 100 -width 200
 tlabel .vpane.files.index.title \
 	-text [mc "Staged Changes (Will Commit)"] \
 	-background lightgreen -foreground black
-ttext $ui_index -background white -foreground black \
+ttext $ui_index \
 	-borderwidth 0 \
 	-width 20 -height 10 \
 	-wrap none \
@@ -3321,7 +3324,9 @@ if {!$use_ttk} {
 
 foreach i [list $ui_index $ui_workdir] {
 	rmsel_tag $i
-	$i tag conf in_diff -background [$i tag cget in_sel -background]
+	$i tag conf in_diff \
+		-background $color::select_bg \
+		-foreground $color::select_fg
 }
 unset i
 
@@ -3429,7 +3434,7 @@ if {![is_enabled nocommit]} {
 }
 
 textframe .vpane.lower.commarea.buffer.frame
-ttext $ui_comm -background white -foreground black \
+ttext $ui_comm \
 	-borderwidth 1 \
 	-undo true \
 	-maxundo 20 \
@@ -3558,7 +3563,7 @@ bind .vpane.lower.diff.header.path <Button-1> {do_file_open $current_diff_path}
 #
 textframe .vpane.lower.diff.body
 set ui_diff .vpane.lower.diff.body.t
-ttext $ui_diff -background white -foreground black \
+ttext $ui_diff \
 	-borderwidth 0 \
 	-width 80 -height 5 -wrap none \
 	-font font_diff \

lib/themed.tcl

@@ -1,6 +1,44 @@
 # Functions for supporting the use of themed Tk widgets in git-gui.
 # Copyright (C) 2009 Pat Thoyts <patthoyts@users.sourceforge.net>
 
+
+namespace eval color {
+	# Variable colors
+	# Preffered way to set widget colors is using add_option.
+	# In some cases, like with tags in_diff/in_sel, we use these colors.
+	variable select_bg		lightgray
+	variable select_fg		black
+
+	proc sync_with_theme {} {
+		set base_bg		[ttk::style lookup . -background]
+		set base_fg		[ttk::style lookup . -foreground]
+		set text_bg		[ttk::style lookup Treeview -background]
+		set text_fg		[ttk::style lookup Treeview -foreground]
+		set select_bg	[ttk::style lookup Default -selectbackground]
+		set select_fg	[ttk::style lookup Default -selectforeground]
+
+		set color::select_bg $select_bg
+		set color::select_fg $select_fg
+
+		proc add_option {key val} {
+			option add $key $val widgetDefault
+		}
+		# Add options for plain Tk widgets
+		# Using `option add` instead of tk_setPalette to avoid unintended
+		# consequences.
+		if {![is_MacOSX]} {
+			add_option *Menu.Background $base_bg
+			add_option *Menu.Foreground $base_fg
+			add_option *Menu.activeBackground $select_bg
+			add_option *Menu.activeForeground $select_fg
+		}
+		add_option *Text.Background $text_bg
+		add_option *Text.Foreground $text_fg
+		add_option *Text.HighlightBackground $base_bg
+		add_option *Text.HighlightColor $select_bg
+	}
+}
+
 proc ttk_get_current_theme {} {
 	# Handle either current Tk or older versions of 8.5
 	if {[catch {set theme [ttk::style theme use]}]} {