[gentoo-user] KDE-4 multi-monitor + fullscreen applications

[Florian Philipp]

Hi list!

Today, KDE nearly killed a presentation I held and now I want to
understand what's going on:

Following setup: One laptop, two outputs (internal display + projector).

Now I configure KDE to expand the desktop on both (instead of simple
cloning). So far, so good.

First question: How does KDE choose on which output the "standard"
desktop ends up and which gets the second set of desktop background +
plasma widgets? It seems like the one with the higher resolution is
standard and on a draw, it is the right-most. Is that correct? Can it be
configured?

Now that I have both desktops, I open Acroread or Okular and start the
fullscreen/presentation mode. What happens is that the presentation is
deterministically opened on one of the displays. What I don't understand
is how it chooses which one it uses?

It doesn't depend on the placement of the window (although other
applications like Flash in Firefox, MPlayer, Kaffeine and Gwenview do).
It doesn't always open on the secondary or standard desktop (as
specified above). It rather seems like it always opens on the one with
the higher resolution and if both are equal, it opens on the left-most.

So, what happened when I tried to hold my presentation? The projector
had a low resolution (1024x768) and therefore neither Acroread nor
Okular showed on fullscreen on the projector. None of my previous tests
showed that problem since I used two displays with equal resolution.
Great fun! In the end, I cloned the output and thereby gave Okular no
other choice. (Lucky me that I didn't any additional notes or anything
on the other display ...)

What can I do to influence this behavior?

Edit: I just noticed that both applications have settings for this.
However, they are ignored and the setting in Acroread is even reset to
"Current display" each time I close the settings dialog! What is going
on here?

Thanks in advance!
Florian Philipp