Re: [PATCH v2] git-gui: use gray background for inactive text widgets

> Second version; it simplifies the code to initialize and update the colors in
> the two file list views a bit, and it calculates a gray color for the inactive
> selection from the active selection. This looks a lot better in the themes I
> have tried.
> 
> The bug with the inactive diff selection background on Mac is still there,
> however.
> 
> --- 8< ---
> 
> This makes it easier to see at a glance which of the four main views has the
> keyboard focus.

> ---
>  git-gui.sh     | 18 ++++++++++++------
>  lib/themed.tcl | 21 +++++++++++++++++----
>  2 files changed, 29 insertions(+), 10 deletions(-)
> 
> diff --git a/git-gui.sh b/git-gui.sh
> index 867b8ce..e818caa 100755
> --- a/git-gui.sh
> +++ b/git-gui.sh
> @@ -720,9 +720,6 @@ proc rmsel_tag {text} {
>  		-background [$text cget -background] \
>  		-foreground [$text cget -foreground] \
>  		-borderwidth 0
> -	$text tag conf in_sel\
> -		-background $color::select_bg \
> -		-foreground $color::select_fg
>  	bind $text <Motion> break
>  	return $text
>  }
> @@ -3322,11 +3319,20 @@ if {!$use_ttk} {
>  	.vpane.files paneconfigure .vpane.files.index -sticky news
>  }
> 
> +proc set_selection_colors {w has_focus} {
> +	foreach tag [list in_diff in_sel] {
> +		$w tag conf $tag \
> +			-background [expr {$has_focus ? $color::select_bg : $color::inactive_select_bg}] \
> +			-foreground [expr {$has_focus ? $color::select_fg : $color::inactive_select_fg}]
> +	}
> +}
> +
>  foreach i [list $ui_index $ui_workdir] {
>  	rmsel_tag $i
> -	$i tag conf in_diff \
> -		-background $color::select_bg \
> -		-foreground $color::select_fg
> +
> +	set_selection_colors $i 0
> +	bind $i <FocusIn>	{ set_selection_colors %W 1 }
> +	bind $i <FocusOut>	{ set_selection_colors %W 0 }
>  }
>  unset i
> 
> diff --git a/lib/themed.tcl b/lib/themed.tcl
> index eda5f8c..db49085 100644
> --- a/lib/themed.tcl
> +++ b/lib/themed.tcl
> @@ -6,8 +6,10 @@ 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
> +	variable select_bg				lightgray
> +	variable select_fg				black
> +	variable inactive_select_bg		lightgray
> +	variable inactive_select_fg		black
> 
>  	proc sync_with_theme {} {
>  		set base_bg		[ttk::style lookup . -background]
> @@ -19,6 +21,8 @@ namespace eval color {
> 
>  		set color::select_bg $select_bg
>  		set color::select_fg $select_fg
> +		set color::inactive_select_bg [convert_rgb_to_gray $select_bg]
> +		set color::inactive_select_fg $select_fg
> 
>  		proc add_option {key val} {
>  			option add $key $val widgetDefault
> @@ -36,11 +40,20 @@ namespace eval color {
>  		add_option *Text.Foreground $text_fg
>  		add_option *Text.selectBackground $select_bg
>  		add_option *Text.selectForeground $select_fg
> -		add_option *Text.inactiveSelectBackground $select_bg
> -		add_option *Text.inactiveSelectForeground $select_fg
> +		add_option *Text.inactiveSelectBackground $color::inactive_select_bg
> +		add_option *Text.inactiveSelectForeground $color::inactive_select_fg

>  	}
>  }
> 
> +proc convert_rgb_to_gray {rgb} {
> +	# Simply take the average of red, green and blue. This wouldn't be good
> +	# enough for, say, converting a photo to grayscale, but for this simple
> +	# purpose of approximating the brightness of a color it's good enough.
> +	lassign [winfo rgb . $rgb] r g b

> +	set gray [expr {($r / 256 + $g / 256 + $b / 256) / 3}]
> +	return [format "#%2.2X%2.2X%2.2X" $gray $gray $gray]
> +}
> +
>  proc ttk_get_current_theme {} {
>  	# Handle either current Tk or older versions of 8.5
>  	if {[catch {set theme [ttk::style theme use]}]} {