Get the active window in Gtk using the wnck library.

get_active_window.py

import wnck
import gtk
import time

if __name__ == '__main__':
  screen = wnck.screen_get_default()
  screen.force_update()
  while True:
    while gtk.events_pending():
      gtk.main_iteration()
    time.sleep(0.5)
    print screen.get_active_window().get_name()

while gtk.events_pending():
    gtk.main_iteration()

Why is this part needed?

It seems that gtk does not update the window title unless you process all pending events first. If you remove the two lines, you should see that the window title will not be updated correctly (at least on my system that's the case). I'm not entirely sure why GTK behaves this way myself, but this hack seems to fix it.

Thanks Adewes !!!

I wish I found this 7 hours ago. I was very confused why my program doesn't upgrade it's window and I was totally mad for the past 7 hours trying to figure out what's the problem. I actually thought that the screen.force_update() was doing the update, but now I know it doesn't. The

while gtk.events_pending():
    gtk.main_iteration()

lines were my gem. Thanks a ton.