Slot for Qt native focus-changed signal to notify Qtmacs if
        the window was switched.

        .. note: This method is work in progress.

def qteFocusChanged(self, old, new):
        """
        Slot for Qt native focus-changed signal to notify Qtmacs if
        the window was switched.

        .. note: This method is work in progress.
        """
        # Do nothing if new is old.
        if old is new:
            return

        # If neither is None but both have the same top level
        # window then do nothing.
        if (old is not None) and (new is not None):
            if old.isActiveWindow() is new.isActiveWindow():
                return