RFC: Make X11 window rect empty for WS_EX_TRANSPARENT windows

[Octavian Voicu]

Hi,

Attached patch fixes http://bugs.winehq.org/show_bug.cgi?id=28678.

The root problem is that X11 windows cannot be made transparent (allowing
other windows to draw over them). My approach I to make the X11 window with
WS_EX_TRANSPARENT extended style have an empty region.

Obviously, this is very hacky and except for very particular cases (like
the bug I'm trying to fix) it won't work at all, so this patch is more like
a proof-of-concept than a fix. For example, window decorations aren't drawn
and not even the window can paint itself. This becomes kind of a recursive
question -- how to draw the contents of the window-less window?

Can this approach ever work? Any comments or suggestions are welcome.

Octavian