Re: RFC: FULLSCREEN_MONITORS property

["Elijah Newren" <newren gmail com>]

Just a few extra cents...

On 3/4/07, Havoc Pennington <hp redhat com> wrote:
> Here are a bunch of questions ;-)
>
> First, a background point. Owen and I had a long thread with Kevin
> Martin a couple years ago (which was in private mail I think,
> unfortunately). Anyway, the claim I was making then was that Xinerama is
> overloaded to mean at least two things:
>
>   a) "I have one big monitor that happens to be made up of multiple LCD
>     panels / CRTs" - e.g. a video wall, is the extreme case
>   b) "I have two monitors and wish to be able to move windows between
>     them" - most commonly a plain dual-head or triple-head setup

<snip some good background and questions>

> Fourth, excluding VMWare, what hints are missing...
> we could add _NET_WM_FULLSCREEN_ALL_MONITORS or something, but I think
> that might be wrong. It might be more correct to implement a property,
> to be honored by both WMs and toolkits, that essentially says "ignore
> Xinerama, this is case a) not case b)" - and then the existing
> _NET_WM_FULLSCREEN would cover all the monitors, and other "Xinerama
> awareness" would also be disabled.

Do we really want a screen global property rather than a
window-specific property?

> Can anyone come up with a use case (other than VMWare) that would need
> to force fullscreen to all monitors in case b)?

I'd like to hear the VMWare case explained too.  I think I read it on
Christian's or Phillip's blog a while ago, but no longer remember any
details.  (Note: I don't know much about VMWare, so don't assume much
in your explanation)

I thought we had some other bug reports about this, but all I could
find is: http://bugzilla.gnome.org/show_bug.cgi?id=119187 (user wants
special key for maximizing their IDE across all monitors).

We also have an orthogonal fullscreen request (which I'm mentioning
just for completeness); basically in determining which of the
conflicting hints of fullscreen and non-resizability take precedence.
(In particular, games often don't want to be resized by the user, but
want to allow requests from the application to be made fullscreen).
See http://bugzilla.gnome.org/show_bug.cgi?id=130404.

> Fifth, I guess we could complicate things by allowing combinations of a)
> and b) - "these two monitors form one monitor and this third monitor is
> separate"

David's patch does that, if I read correctly in my quick scanning of
it.  My question is: why is this useful?  Would a simpler
fullscreen-across-all-monitors hint be sufficient?

> Sixth, I can imagine wanting to switch between a) and b) depending on
> context; maybe you play your flight simulator with your three monitors
> as one big screen, but when doing anything else you want three separate
> monitors. This quickly becomes a serious programming and UI nightmare...
> perhaps the proposed hint would fix it though by providing an "escape hatch"

I can see that this would be a nightmare if the hints were global to
the screen rather than specific to each window.  I don't see any
problems with the latter, right now.  Can others think of any?


Elijah