Re: Pluggable settings daemon

[Rodrigo Moya <rodrigo gnome-db org>]

On Thu, 2007-11-15 at 13:29 -0500, William Jon McCann wrote:
> Hi,
> 
> During the work on the GDM rewrite for 2.22 it became clear that we
> needed to run some kind of settings daemon in the greeter/login-window
> session.  At first I tried to use gnome-settings-daemon directly but
> this was problematic for a few reasons, including:
> 
could you explain why you need that settings daemon? Not that I have
anything against it, just want to know in detail why you need it :-)

>  * The current settings daemon is only modular at the gobject level
> [1].  It is all or nothing.  And it isn't clear that we want to have
> all of these objects (eg. keybindings and typing break) loaded at the
> login window.
>  * At least to some people, the idea of GDM depending on
> gnome-control-center may be undesirable.
> 
> 
> So, I decided to create a pluggable settings daemon for GDM [2].  And
> then converted the gnome-settings-daemon's xsettings stuff into a
> plugin for it [3] since that was the only part that I needed right
> away.
> 
> Do you think it makes sense to use this for both GDM and
> gnome-control-center?  Perhaps each session can simply specify which
> plugins should be loaded.  Where GDM will likely be a subset of a full
> GNOME session.
> 
it makes a lot of sense, and if we are going to share it, I guess we
could:

- have the daemon in GDM
- have the modules you need in GDM
- have the other modules in gnome-control-center, and load them when the
session starts.

There are some issues though that came to mind:
- would GDM run the daemon and leave it running when the user logs is?
or would it kill the daemon and the session would start it again with
the new set of modules? In any case, when running KDM/XDM, we would need
to run the settings daemon in the session, so I guess it would be better
to just run it in GDM, kill it, and then re-run it in the session
- would having g-c-c depend on GDM be ok?
- what about having gnome-settings-daemon as an independent module on
which both GDM and g-c-c depend? We could have command line arguments
for both to indicate what modules they want loaded

Whatever we decide, what is clear is that we can share the settings
modules. I changed the g-s-d architecture for the modules in a way that
it would be easy to add code to load external modules, so we can have
the shared modules as part of GDM and then do whatever is better with
the daemon. Of course, if both daemons are going to do the same, it
makes a lot of sense to share it, so I'm inclined to think it makes a
lot of sense to have gnome-settings-module as a separate module.
-- 
Rodrigo Moya <rodrigo gnome-db org>