Re: What is a GdkScreen?

[Robert Pearce <rob bdt-home demon co uk>]

Hi Johannes,

On Tue, 2 Nov 2010 20:25:12 +1000 you wrote:
> 
> If I understand correctly, a GdkDisplay is basically an X server
> instance. A monitor is, well, a monitor. GdkScreen is supposed to be
> somewhere in the middle.

OK, took me a while to find monitor, but...

> The GDK multihead documentation has this to
> say about the topic:
> 
> > GdkScreen objects are the GDK representation of a physical screen.
> 
> Yet that sounds like the definition of a monitor.

Almost. I think (and it's ages since I did any multi-screen stuff on X)
that Xinerama confuses things by pretending to be one physical screen.
The traditional X multi-screen approach was to declare each physical
monitor as a separate screen identified by a suffix on the DISPLAY
variable. If you took that approach, a GdkScreen would map to a
physical screen, and the GdkDisplay would be the controlling X server.
If you're using Xinerama, I think all monitors grouped by that make up
one GdkScreen.

So, if I understand right (which is by no means certain), a GdkScreen
is the display area you can drag a window over, rather than having to
plonk it onto another screen by other means.

Then again, there's the whole issue of virtual screens and compositing
window managers to make it potentially entirely different.

Now with any luck somebody that knows what they're talking about will
come along and correct me.

Cheers,
Rob