Re: "modern" colors Re: Changes for emacs 28

[Ricardo Wurmus]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Ricardo Wurmus <rekado@elephly.net>
>> Cc: spacibba@aol.com, casouri@gmail.com, emacs-devel@gnu.org, ams@gnu.org,
>>  monnier@iro.umontreal.ca, ghe@sdf.org, tecosaur@gmail.com
>> Date: Sun, 13 Sep 2020 18:22:11 +0200
>> 
>> > The behavior you have on your system isn't the Emacs default: we don't
>> > invert colors to display the region, we only specify a different
>> > background color (see the default definition of the 'region' face).
>> 
>> I’m used “emacs -Q” and I’m on Guix where we don’t patch Emacs to have
>> different defaults.  I also have nothing in my .Xdefaults or .Xresources
>> that should affect Emacs.
>
> Then it's a mystery only you can solve.  Look at the definition of the
> 'region' face in faces.el: the only case where we use :inverse-video
> is on monochrome TTYs.  If that is not your case, then I don't know
> how to explain the fact that you see the region in reverse video.  I
> guess I'm missing something, but what?

The ’region’ face has these settings:

  DistantForeground: gtk_selection_fg_color
         Background: gtk_selection_bg_color

I switch to a light GTK theme and run Emacs:

  $ dconf write /org/gnome/desktop/interface/gtk-theme "'Adwaita'"
  $ emacs -Q

Now the selected region has a light gray background.

I switch to a dark GTK theme and run Emacs:

  $ dconf write /org/gnome/desktop/interface/gtk-theme "'Adwaita-dark'"
  $ emacs -Q

Now the selected region has a very dark background and the text is
bright.

I suppose that’s exactly what gtk_selection_bg_color and
gtk_selection_fg_color are supposed to do: take the colours from the GTK
theme.

On Guix we build Emacs with the GTK toolkit.

-- 
Ricardo