Composite overlay window

[Deron Johnson]

Kristian Høgsberg wrote On 03/23/06 15:14,:
> Hi,
> 
> I was discussing the new overlay window additions in composite with 
> Søren, and he pointed out that there is no way to specify the visual for 
> the overlay window:
> 
> 	Window
> 	XCompositeGetOverlayWindow (Display *dpy, Window window);
>    	
> 	void
> 	XCompositeReleaseOverlayWindow (Display *dpy, Window window);
> 
> and reading the code, it turns out that it's just using the root visual. 
>   I was of the impression that one of the compelling arguments for going 
> with the overlay window approach was that you'd get to specify the 
> visual when creating the overlay window.

We discussed the possibility of putting the overlay window in an overlay
visual, but I view that as a minor tweak. It doesn't help composite
managers very much and the main reason for the extension is for
composite managers.

> Should we add a visual argument to XCompositeGetOverlayWindow? 

If you would like, you can add this as another version of the extension.
Something like XCompositeGetOverlayWindowWithVisual. My composite
manager doesn't want to mess around with trying to find a visual
it just wants to use the default, so I would rather keep the existing
more simple version. But you can add a more complicated version if you
would like,

> Also, it 
> looks like the only reason for passing in a window is to get at the 
> screen that window belongs to.  In that case, I think it would be 
> clearer to just pass in the screen number.

This is a standard practice in many X11 requests. I don't think
it needs to be changed.