EWMH proposal for _NET_WM_WINDOW_OPACITY

[Keith Packard]

Around 0 o'clock on Dec 19, Lars Hallberg wrote:

> If I understand You right, X  do now suport semitransparant windows so 
> the directFB hack with transparent unfokused windows only needs a 
> windowsmanager to suport it? I have been strongly beleving this was a 
> directFB hack only.

The window manager support is only needed to forward the property from the 
application window to the frame; with the Composite extension, a 
compositing manager can then take that value into account when 
constructing the desktop image.  Any X server can implement the Composite 
extension; the one in the X server project at freedesktop.org is just one 
such.  It would be trivial to implement this extension in a direct FB 
based X server, or any other X server which places windows in off-screen 
images.

> wm: focused window 100% opasity
> wm: unfokused window 50% opasity
> app: 80% opasity -> focused 80%, unfokused 40%

Ah, that's a cool idea -- add some Window Manger/Compositing Manager 
communication hints so we can communicate focus changes and such like up 
to the compositing manager for it to use in constructing the desktop 
image.  One thing OSX does is 'deepen' shadows for the window with the 
focus; doing this translucency thing might be neat too as X doesn't insist 
on the focus window being on top.  Hmm.  More code to play with.

-keith