Re: Planned GNOME Shell UI changes (was Re: String and UI Change Announcement)

[Owen Taylor <otaylor redhat com>]

On Mon, 2011-01-10 at 19:03 +0100, Josselin Mouette wrote:
> Le lundi 10 janvier 2011 à 12:33 -0500, Owen Taylor a écrit : 
> > * UI will be added for displaying information about fallback mode
> >    and forcing fallback mode when the system seems capable of doing
> >    a full composited desktop.
> > 
> >    (This is my biggest area of concern going into GNOME 3.0 - not
> >    having the final design or much code for this.)
> 
> Is it really necessary? wouldn’t it be simpler to let the user choose in
> GDM, provided the packages necessary for fallback mode are installed?

There are multiple ways that GDM could be involved here:

 * We could get GDM involved in figuring out whether we want to
   run in normal mode or fallback mode.

 * We could implement normal mode and fallback mode as two separate
   independent session types.

 * We could simply use the existing session selector to select
   between two independent session types.

The first two are definitely possible, I'm not sure if they buy a lot
compared to doing the selection in gnome-session after we start the
login process.

The third one - which I understand to be your proposal - I don't think
it works.

I'd like us to be designing for the set of users for whom that choice
simply wouldn't make sense. People should be able to expect that you
click on your user, you log in, and the right thing happens. So we need
to have logic that automatically chooses what to do (Vincent has already
added some of this to gnome-session) and then we need a way for the user
to override in the cases that I mentioned.

That is the config part of the equation.

The other part of the equation "displaying information about fallback"
mode comes into play, if say, I plug a new video card into my system,
reboot, and suddenly we no longer support 3D. We can't just throw the
user into a quite radically different experience with no explanation.

We need some sort of dialog/troubleshooting to say:

 - Here's what happened
 - Here's the information about your system you might need to
   figure out what you need to do to get working drivers.

- Owen