Re: Fullscreen across multiple heads

[Lubos Lunak <l lunak suse cz>]

On Wednesday 15 November 2006 04:28, Philip Langdale wrote:
> Hi all,
>
> My name is Philip Langdale and I work at VMware. Some of you may
> know from me from some of the other projects I've worked on like
> Galeon, but I'm largely here with my work hat on.
>
> It's possible some of you may have noticed the latest Vmware
> Xorg video driver changes to go in which add Xinerama support.
> This is part of a larger feature in the upcoming Workstation 6
> which is to support the reflection of host multi-head into a
> guest.
>
> At this point, you can guess where I'm going. To do this properly
> we will need to construct a fullscreen window that spans multiple
> heads, up to and including all heads. Right now, the wm spec only
> defines fullscreen for a single head,

 Not really, it doesn't say anything about it, it simply defines fullscreen. 
At least I don't read the "screen" in there as "Xinerama screen" but simply 
as screen. In KWin it in fact is configurable whether fullscreen spans all 
Xinerama screens or just one.

> so doing multi-head fullscreen 
> requires us to fall back to the techniques of the
> pre-single-head-fullscreen days - and as you may know, metacity tries
> terribly terribly hard to make hand-rolled fullscreen windows impossible.

 I think you'd have the same problem with KWin, as it handles the old-style 
fullscreen windows just like the new-style ones. However, it is possible to 
use window-specific settings to make exceptions.

> We think we can probably manage it by abusing window type hints (ie:
> expect the biggest 'notification' window you've ever seen...) but this
> obviously very sub-optimal.

 It can easily be also very sub-working.

> As such, we really hope that formal handling for multi-head fullscreen
> can be added to the upcoming 1.4 release of the wm spec.
>
> Obviously, a more formal discussion of the mechanism and wording will
> be necessary, but the simple concept needs to be discussed and validated
> first.

 I wonder a bit if this perhaps wouldn't be better left to the WM, but I think 
I wouldn't be against adding TYPE_FULLSCREEN_FULL. Ok, with a better name :).

-- 
Lubos Lunak
KDE developer
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