Re: Session manager questions

[Robert Bihlmeyer <robbe orcus priv at>]

Hi,

>>>>> On 19 Feb 1999 09:34:25 -0500
>>>>> Gisli Ottarsson <gisli@master.adams.com> said:

 Gisli> As has been stated here, the idea behind the session
 Gisli> management seems to be that whatever the user had running at
 Gisli> the end of a session will be restarted during a follow-up
 Gisli> session. This includes the window manager.

Basically, yes.

 Gisli> If correct, this seems somewhat fragile. For instance, if you
 Gisli> log out or are logged out because your window manager died,
 Gisli> will you the not be missing a window manager the next time you
 Gisli> log in?

First: why should you be logged out when your wm dies? The recommended 
way to go with SM is to put the session manager (e.g. "gnome-session") 
last in your X init file. So you will not be logged out while the
session manager runs.

Second: there is a "Restart Style Hint" that can be set by SM-aware
applications. When I put SM into scwm, I let it set this to "Restart
Immediately". This causes an *immediate* restart if the app in
question dies - usually the right thing for ubiquitous things like the
wm. If the user deliberately exits scwm (perhaps to start another wm),
this behaviour is of course disabled.

 Gisli> Also, it makes the process of changing window managers
 Gisli> ambiguous. Is killing your window manager and starting a new
 Gisli> one before logging out the right way to do it?

Yes.

 Gisli> Where do "Gnome Session Properties" come into this? The System
 Gisli> section in the System Menus provides access for this dialog
 Gisli> box (should it be accessible from the Control Center instead?)
 Gisli> It would seem that this dialog box could allow the user to
 Gisli> configure two lists of applications:

 Gisli>   Applications that should *always* be started (e.g. window
 Gisli>   manager)

 Gisli>   Applications which should *never* be restarted when
 Gisli>   restoring a session, presumably because the don't know what
 Gisli>   to do. Right now, for instance if you started emacs in a
 Gisli>   session by giving it a relative path, emacs is unlikely to
 Gisli>   find this file on restart.

There are also hints for "Restart If Running" (the default), "Restart
Always", and "Restart Never". These can pretty much model the
behaviour you want. Unfortunately there is no way for the user to set
this right now. This would be a most valuable feature. Look at "xsm",
how this could look like (not that xsm is anything like optimal).

BTW, the Emacs example should work, because the working directory is
one of the things saved.

 Gisli> Note that a fickle user playing the window manager field would
 Gisli> be returned to his chosen window manager (the "always start"
 Gisli> choice) and a window manager "fling" would not start because
 Gisli> it would detect that another window manager has been started.

This is a bit against the spirit of SM. I think that simply the last
wm running should be restarted. SM does not give you a big
advantage if you still have to go through editing just to switch the
wm.

The SM way to do it (IMHO) is to allow saving "snapshots" or
"checkpoints" and later reloading these at arbitrary times. (Out of
the box the session-manager implicitly checkpoints if you end the
session, and restores this checkpoint on restart.) So you once
checkpoint your proven-working setup with one wm, then you can try out 
other things, and if you're unsatisfied, just go back to the
checkpoint with a few clicks.

	Robbe

-- 
Robert Bihlmeyer	reads: Deutsch, English, MIME, Latin-1, NO SPAM!
<robbe@orcus.priv.at>	<http://stud2.tuwien.ac.at/~e9426626/sig.html>