location management vs. session management

[Havoc Pennington <hp redhat com>]

Hi,

I'm curious about the master plan for session management and location
management, and their combination. 

As I understand it, the current UI/plan for session management is that
on login, you can name your session, say "big screen session" or "work
session" or whatever.

Then the settings I change during the session will be saved
per-session. Applications can also choose to save some settings as
global (applying to all sessions). For example, the panel setup is
certainly per-session, but my http proxy may not be.  (It's hard to
know how this should work, exactly. For GConf we had hashed out a plan
that would allow people to configure it on a per-key level if they
were willing to drop down to the command line, and have reasonable
defaults otherwise.)

Anyhow, on login I can also choose an existing session to use as
appropriate, so I'd choose my "big screen session" when I have a big
screen.

We could also easily implement session copying, so I could base one
session on another. At least I'm pretty sure we could do this (the SM
would pass the previous session ID to clients on startup, but then
when they registered, give them a new session ID, perhaps?). This
would happen at session creation time; I create a new session named
"foo" and it lets me choose another session to base it on.

So how does this relate to location management? Say I have several
locations; are sessions "inside" a location? Or are locations "inside"
a session?

How do I choose a location? If gdm already lets you choose a session,
does it make sense to have the user choose both a session and a
location in gdm? Or is there some other UI for choosing a location?

To put that concretely, if the panel has session-specific config
files, do location settings go in those files or in global files?

Sessions work with non-GNOME apps. For example, I am trying to get it
into Mozilla, and it works with Qt apps. Can locations ever work with
non-GNOME apps? Or are they intended to work with apps at all - is it
just desktop settings? What if I want to have location-specific stuff
in my word processor or web browser?

I'm concerned that it's confusing to have both "locations" and
"sessions," and maybe we need to think this through a bit more.

I'm not really familiar with the details of either one, but I'd like
to be. Comments welcome.

Havoc