How can I find out or record the X11 top-level window from which a top-level window was opened?

Question

I'm thinking of writing an X11 window manager which does for windows something like what TabKit does for tabs in Firefox (in its default tree view mode). To do this, I'd need to be to able to find out which window a window was opened from. Is there a standard way of finding this out?

(I've never done any X11 programming without using a cross-platform toolkit on top of X11, let alone writing a window manager.)

Answer 1

For the difficult cases - applications launching other applications, e.g. a word processor launching a web browser - there's going to be a need for co-operation between applications to track this information. The Zeitgeist project already seeks to track which documents were opened from which documents, which is close enough that I should probably work with Zeitgeist (and/or its KDE equivalent - Nepomuk?) to get this implemented.