[PATCH 3/3] compositor-drm: add sprite support v5

[Bill Spitzak]

Pekka Paalanen wrote:

> < krh> alternatively, we could just man up and make a surface tree

I hope at least one person read my other email.

No tree is necessary (besides it would be an directed acyclic graph, not 
a tree). Wayland can keep a straight list. The compositor is not allowed 
to rearrange the surfaces that belong to the same client and role, but 
it is allowed to "shuffle" multiple clients together in a stable-sort 
method by using the "role" to do so.

The *only* way to reorder windows belonging to the same role+client is 
to respond to a client-requested "raise" command. This command must also 
somehow specify an atomic group of raises, additions of new windows, and 
resizes of windows. It may also have to atomically remove old windows 
but I have reason to believe that can be worked around.

Anybody thinking the compositor can somehow "raise on click" has got to 
try writing a real program that has multiple main windows, multiple 
dialog boxes and drag & drop. It is not possible without moving the 
entire toolkit to the compositor.