Re: Panel behaviour under Xinerama

[Alexander Larsson <alexl redhat com>]

On 8 May 2003, Bill Haneman wrote:

> On Thu, 2003-05-08 at 12:08, Shane OConnor - Sun Ireland wrote:
> > 
> > Hey Mark,
> > 
> > AFAIK the idea of xinerama is that you can setup multiple (eg, 2) monitors to 
> > act as one single monitor so I'd expect there to be one panel top or bottom that 
> > stretches accross 2 monitors[1].
> 
> Yes, this is the primary difference between "plain multihead" and
> "xinerama".   They look quite different to apps in general since
> "xinerama" isn't really multihead, i.e. there is only one GdkScreen with
> Xinerama (it spans two physical framebuffers).
> 
> I agree that when using Xinerama the correct thing to do is treat the
> display as a single entity, i.e. span both monitors.  If that doesn't
> give the user their desired behavior they can:
> 
> * switch to multihead instead, or
> * use panels that don't expand
> * put the panel at the top of the display, to prevent problems if the
> screen heights don't match
> 
> My experience, in dealing with other Xinerama-vs-multihead issues in the
> past (i.e. CDE, etc.), was that trying to make certain applications
> "smart" about multihead (i.e making them aware of the physical screens)
> led to a lot more problems than it solved.  And of course if you change
> the xinerama behavior to make one user happy, you will upset two other
> users ;-)

One thing you could do is to detect these two cases:

 +-----+ +-----+
 |     | |     |
 |     | |     |
 +-----+ |     |
         +-----+

and
	 
 +-----+ +-----+
 |     | |     |
 |     | |     |
 |     | +-----+
 +-----+
         
And handle the case where the panel is at the bottom by not extending into 
the part that isn't visible.

(
I assume this never happens:
 +-----+ 
 |     | +-----+
 |     | |     |
 |     | |     |
 +-----+ +-----+
)


-- 
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 Alexander Larsson                                            Red Hat, Inc 
                   alexl redhat com    alla lysator liu se 
He's a notorious umbrella-wielding inventor on the edge. She's a virginal 
junkie museum curator with the power to bend men's minds. They fight crime!