Re: Display configuration capplet

[Bryce Harrington <bryce canonical com>]

On Thu, Feb 14, 2008 at 03:45:25AM +0100, Soeren Sandmann wrote:
> Bryce Harrington <bryce canonical com> writes:
> 
> > In looking at http://www.gnome.org/~ssp/randr/capplet/, it appears the
> > development done so far has focused on a monitor hotplug feature and the
> > start of a cairo-based monitor layout canvas.  
> 
> This is all intended to be added to gnome-desktop,
> gnome-settings-daemon, and gnome-control-center for 2.24.

Thanks for explaining all of this in detail.  I just wish I'd known more
about this earlier.  Do you have this checked into a public VCS
somewhere?

> Here is an overview of how it works:
> 
> There is a new file, $HOME/.gnome2/monitors.xml, that maps a monitor
> setup (= what monitors are connected to which outputs) to information
> about what modes and positions the monitors have in the virtual
> framebuffer.

How does one reconfigure the monitor layout (such as if you wish to
switch the left monitor to the right)?
 
> When the user hits apply, the new configuration is added to
> monitors.xml, and the capplet signals gnome-settings-daemon to reread
> the configuration. G-s-d will then apply the new settings.

Is there also an intent to provide the user with a way to disable
outputs?  (I don't know if this is a very common use case, except
perhaps for debugging purposes or something...)
 
> That much is working already. For Fedora 9, some additional features
> are planned:
> 
>     - Clone mode
> 
> This is not implemented yet, but needs to be.

Is anyone planning to work on this currently?
 
>     - Make the 'Virtual' size dynamically changable in X
> 
> So that the user doesn't have to change xorg.conf

Is there a design approach in mind for how this would be solved?
 
> > There is a randrwrap but it appears to not have the xrandr 1.2
> > multi-head functionality, and isn't integrated with the GUI yet.
> 
> randrwrap.[ch] is a simple wrapper around xrandr that uses the glib
> mainloop to keep the RandR information up-to-date automatically. It
> supports everything xrandr 1.2 supports, including multi-head. 
> 
> I don't know what you mean by "isn't integrated with the GUI yet". The
> capplet GUI uses randrwrap.[hc].

I just did not see controls for setting left-of/right-of; also, the
daemon was not building:

> If you tried it out and found that it didn't do anything when you
> clicked apply, that's just because you don't have the appropriate
> gnome-settings-daemon changes.

Right, the gnome-settings-daemon did not build at that time so I wasn't
running it.  It needed to have monitor-db.c, edid-parse.c, randrwrap.c,
and display-name.c added to the build.sh.  After that was fixed, it
built and ran properly.

Bryce