[Lazarus] window classes according to WM

[David Emerson]

Hi all,

What is the property that determines the window class, as seen by the WM / xorg?

I'm asking for the purpose of grouping: I'd like to be able to have distinct 
groups of windows that the WM will group independently of one another.

As an example, looking at the easter/holydays example, if I use KDE3's edit 
window-specific settings dialog I can detect window properties. It shows me

Class: Holyday (holyday Holyday)

and some other stuff. My assumption is that the class is used by the WM to 
determine which windows are grouped together.

The real reason I'm asking is that in fpgui, the class is undefined and I'd like 
to find out how it's done in lazarus, where it IS defined.

Cheers,
David.