def _add_new_state(self, *event, **kwargs):
        """Triggered when shortcut keys for adding a new state are pressed, or Menu Bar "Edit, Add State" is clicked.

        Adds a new state only if the the state machine tree is in focus.
        """
        if react_to_event(self.view, self.view['state_machine_tree_view'], event):
            state_type = StateType.EXECUTION if 'state_type' not in kwargs else kwargs['state_type']
            gui_helper_state_machine.add_new_state(self._selected_sm_model, state_type)
            return True