bug#57639: [PATCH] Add new command 'toggle-theme'

[Michael Albinus]

Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text
editors" <bug-gnu-emacs@gnu.org> writes:

> If it's automatically switching between dark and light themes, then
> style_changed_cb is probably not the right place.  It's mostly vestigial
> code from when we used to update the region face along with the GTK
> stylesheet.  Instead, TRT used to be to listen for changes to the
> `gtk-application-prefer-dark-theme' property of the GtkSettings object.
>
> However, that has been superseeded by a dbus based interface in recent
> versions of GNOME.  I do not understand the details, but it seems like
> it could be implemented in Lisp:
>
>   
> https://flatpak.github.io/xdg-desktop-portal/#gdbus-org.freedesktop.portal.Settings

Definitely. Example D-Bus code is at 
<https://github.com/doomemacs/doomemacs/issues/6027>.

And if I understand
<https://github.com/flatpak/xdg-desktop-portal/blob/main/README.md>,
this is not restricted to GTK only.

Best regards, Michael.