Qt GUI event recording and playback

I'm attempting to implement a simple, lightweight system for recording Qt GUI events and playing them back from a script. I thought this would be fairly straightforward using the magic of Qt's event system, but I'm running into a problem I don't understand.

Here's quick summary of what I'm doing:

RECORDING:

I use QApplication.instance().eventFilter() to capture all GUI events I'm interested in* and save them to a Python script, in which each step looks something like this:

obj = get_named_object('MainWindow.my_menubar')
recorded_event = QMouseEvent(2, PyQt4.QtCore.QPoint(45, 8), 1, Qt.MouseButtons(0x1), Qt.KeyboardModifiers(0x0))
post_event(obj, recorded_event)

PLAYBACK:

I simply execute the script above, in a worker (non-GUI) thread. (I can't use the GUI thread because I want to keep sending scripted events to the application, even if the 'main' eventloop is blocked while a modal dialog eventloop is running.)

The important stuff happens in my post_event() function, which needs to do two things:

• First, call QApplication.postEvent(obj, recorded_event)
• Wait for all events to finish processing:**
  • Post a special event to the same eventloop that obj is running in.
  • When the special event is handled:
    • Call QApplication.processEvents()
    • Set a flag that tells the playback thread it's okay to continue

After the second part is complete, my expectation is that all effects of the first part (the recorded event) have completed, since the special event was queued after the recorded event.

The whole system mostly seems to work just fine for mouse events, key events, etc. But I'm having a problem with QAction handlers when I attempt to play