rootninja

This faq is the most useful pygtk resource you will find. The full documentation is great for looking up which methods to use or what’s available in one class or another, but it’s the little nooks and crannies that are always left out by most pygtk resource sites that I find really annoying.

http://faq.pygtk.org/index.py

How can I force updates to the application windows during a long callback or other internal operation?

If you have a long-running callback or internal operation that tries to modify the application windows incrementally during its execution, you will notice that this doesn’t happen; the windows of your app freeze for the duration.

This is by design: all gtk events (including window refreshing and updates) are handled in the mainloop, and while your application or callback code is running the mainloop can’t handle window update events. Therefore nothing will happen in the application windows.

The trick here is to realize where your operation can take a while to return, or where it is dynamically changing the window contents, and add a code fragment like this wherever you want an update forced out:

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

This tells gtk to process any window events that have been left pending. If your handler has a long loop, for instance, inserting this snippet as part of the loop will avoid it hanging the window till the callback has finished.