Re: compositing: agreeing on a hint name for CMs requesting to draw the desktop background

[Danny Baumann <dannybaumann web de>]

Hi,

> On Tue, Mar 25, 2008 at 12:42:06PM +0100, Christian Neumair wrote:
> > Compiz sets the _COMPIZ_WALLPAPER_SUPPORTED hint for requesting to draw
> > the desktop background. There is a patch against Nautilus [1] available
> > that uses this hint to draw the folder background with alpha=0.
> 
> >From your email, I can't tell what this hint actually does (or even
> what window it is set on -- the root? -- or who sets it), 

It's set by a Compiz (or better Compiz Fusion) plugin (which aims to
draw per-viewport wallpapers), and is set on the root window. This
property semantically just says "I am able to draw the wallpaper,
there's no need to have the desktop window draw the wallpaper".

> and I can't
> tell why compiz wants to do anything different with backgrounds than
> other WMs (i.e., just use the window with type DESKTOP as the
> background).  Could you perhaps elaborate some?

As said, per-viewport wallpapers or even video wallpapers or similar.
The goal is to have the desktop window draw itself transparent (and keep
only the icons opaque) so other stuff can be drawn underneath it without
losing the actual desktop functionality.

Regards,

Danny