def METHOD_NAME(self, obj, evt):
    interactor = obj.GetInteractor()
    if not self.lmb_pressed:
        return
    if not self.navi:
        return
    self.lmb_pressed = True
    display_pos = interactor.GetEventPosition()
    world_pos = self._to_world_coordinate_2d(display_pos)
    self.route_to = world_pos
    self._render_path()