Fullscreen across multiple heads

[Philip Langdale <philipl overt org>]

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, 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.
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.

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 eagerly await your thoughts.

Thanks,

--phil