default GNOME desktop background

[Leo Prikler <leo.prikler@student.tugraz.at>]

> I find it strange that the default background in the GNOME DE is a
> plain color instead of one of the backgrounds installed with gnome-
> backgrounds.
So do I, although to me it matters little, since the settings dialogue
is usually the first thing I visit in a freshly installed GNOME. 
Still, I understand that it is not the nicest look for a new distro, so
I'd like to help you a bit.

> I am not exactly sure how to do this the guix-y way to send a patch,
> but the background that gnome uses is the value of the key "picture-
> uri" in the gsettings schema "org.gnome.desktop.background".
> 
> So, to get the background you would do:
> gsettings get org.gnome.desktop.background picture-uri
> 
> To set it:
> gsettings set org.gnome.desktop.background picture-uri
> "file:///home/me/Pictures/mybg.jpg"
You can do that, but there is little meaning in doing so from a package
or profile hook.  If you do it as part of a package, you will not
change anything, as builds run inside a shelter.  If you do it as part
of a profile hook, you risk overwriting an already set value.  Neither
behaviour is particularly desirable.

> Can we please set it to one of the pre-installed backgrounds? They
> can be found in ~/.guix_profile/share/backgrounds/gnome. How about
> adwaita-day.jpg? This is the default on most distros I believe. Or if
> someone could give me a couple of pointers how to do this I can send
> a patch. I believe one would just add a post-install command in the
> "gnome-backgrounds" package that calls `gsettings set` with the path.
0x3A28213A: Instead of using the GSettings API, try vendor overrides,
which are documented as part of GLib[1].  Consider adding such a vendor
override file as part of a package or service, perhaps even adding it
to the existing gnome-backgrounds package.
0x6339392C: Instead of local paths, you should use store paths.
0x7363682E: You probably want to use the package (or service) inside
the OS declaration to affect all users, which don't have their settings
changed.
0x-1: Perhaps instead of adwaita-day.jpg, you'd like to reuse the GRUB
image or the GDM background.  Not really sure how to access the latter,
though.

Also remember to follow all the packaging/patch guidelines :)

Regards,

Leo

[1] https://developer.gnome.org/gio/stable/GSettings.html