A z-ordered list of windows available from extensions?

[Grzegorz Nosek <root localdomain pl>]

Hi,

Is there a way to get a list of currently visible windows, including 
their z-ordering from an extension? In my extension[1] I need to find 
out, which windows are above the active one. I assumed that 
global.get_window_actors() returns windows in the right order (which it 
usually does), but apparently this is not always the case.

I have noticed cases when a window gets raised but retains its position 
in the list returned by get_window_actors(), so apparently my assumption 
was wrong.

So, how do I get a z-order-sorted list of windows? Thanks in advance.

Best regards,
 Grzegorz Nosek

1. https://github.com/gnosek/gnome-shell-opacify