Re: Consolidating Core Desktop libraries

[Bastien Nocera <hadess hadess net>]

On Tue, 2010-11-09 at 22:33 +0100, Giovanni Campagna wrote:
> Vincent asked me to send a mail to d-d-l about 	db82a33 in
> gnome-desktop, that is: all libgnome-desktop include files have been
> moved to $(includedir)/gnome-desktop-3.0/libgnome-desktop.
> This is part of an other API break which is related to GnomeRR and
> introspection.
> 
> I consider this an occasion for a bigger discussion on redesigning
> libgnome-desktop, moving forward from being the container of useful
> libgnome parts, to the One Desktop Library.

There are reasons why all those are separate, and I think we should
remember that.

> We're in the middle of moduleset reorganization, drawing a stricter line
> on what is core, and thus is expected to work only in GNOME and requires
> GNOME and is required by GNOME, such wm, the panels, the control center,
> the session daemons, and what is just an app using the GPlatform (GLib -
> GIO - Gtk), which therefore will work on every G- desktop environment.
> 
> I believe this is the time for consolidating shared code used by this
> core modules into a libgnome-desktop, the same way we killed libgnome
> and merged useful features in Gtk / Gio.
> 
> There is a lot of code which is copy-pasted around our desktop. For
> example, the GsdOsdWindow class, used by gnome-settings-daemon and
> gnome-power-manager, had to be updated several times because of Gtk
> breakages.

That's 2 users of the library, there's a similar one in Totem. But those
will be going away when we get those sort of notifications into the
shell directly.

> Another piece of copy-pasted code is gdmuser, which lives in
> gnome-panel, gdm and gnome-shell, and is constantly being updated
> because of accountsservice instability.

Then we need to make accountsservice more stable. And it could probably
ship a small library as well.

> Then there are microlibraries, killing which would help performance.
> These include for example libgtop, libgweather and libgnomekbd, but also

libgweather is small, but the data it drags in isn't.

> liboobs if the system tool backends are not dead.
> I can't find an use for them outside core desktop, while on the other
> hand there are already core desktop packages that depend on them.
> 
> My proposal is then to take the classes included in these libraries or
> copy pasted sources, move them to the Gnome C namespace (GnomeDesktop
> GIR namespace) and add to libgnome-desktop.
> API stability is not an issue, as we all know that
> GNOME_DESKTOP_IS_UNSTABLE_API, and the only users of libgnome-desktop
> should live in the desktop modulesets, so that if we ever break API,
> we'll file patches before the affected maintainers even notices.
> 
> I'm looking forward to read your comments on this.

I'm really not interested in seeing library aggregation of that sort.
We're striving to get rid of most of those, and they will disappear in
due time.

And if it were me, we'd kill gnome-desktop (as a library), and
copy/paste the very few bits between the modules that need it.

There's currently RandR helpers (g-s-d and control-center), wallpaper
handling code (g-s-d, control-center and nautilus), and the thumbnailer
(nautilus only, afaik).

The RandR stuff could be moved in g-s-d, and the wallpaper code as well,
when nautilus stops handling the desktop at some point in GNOME 3. And
nautilus could move the thumbnailer code to use itself.

Then gnome-desktop would only be a location for gnome-about.