def _set_affine(self, *args):
        """ Generate current permutation from entries in the affine box.

        Args:
            *args: arguments provided by the signal
        """
        mult = int(self._mult_field.get_active_text())
        add = int(self._add_field.get_active_text())
        self.set_permutation(Permutation.affine(mult, add))