'Filter mouse press events.
Events that are captured and not propagated return True. Events that
are not captured and are propagated return False.'

def eventFilter(self, obj, event):

    event_type = event.type()
    if (event_type == QEvent.MouseButtonPress):
        self.tab_pressed(event)
        return False
    if (event_type == QEvent.MouseMove):
        self.tab_moved(event)
        return True
    if (event_type == QEvent.MouseButtonRelease):
        self.tab_released(event)
        return True
    return False
