def get_adjusted_border_positions(self):
        """
        Calculates the positions to limit the port movement to
        :return: Adjusted positions nw_x, nw_y, se_x, se_y
        """
        nw_x, nw_y = self._rect[0]
        se_x, se_y = self._rect[1]

        nw_x += self._distance_to_border
        nw_y += self._distance_to_border
        se_x -= self._distance_to_border
        se_y -= self._distance_to_border

        return nw_x, nw_y, se_x, se_y