def ok_button_status(self):
        """Function to enable or disable OK button."""
        if not self.layer.currentLayer():
            self.button_box.button(
                QtWidgets.QDialogButtonBox.Ok).setEnabled(False)
        elif (self.hazard_class_form.count() > 0
              and self.layer.currentLayer().name()
              and len(self.output_form.text()) >= 0):
            self.button_box.button(
                QtWidgets.QDialogButtonBox.Ok).setEnabled(True)
        else:
            self.button_box.button(
                QtWidgets.QDialogButtonBox.Ok).setEnabled(False)
Function to enable or disable OK button.