def classifications_combo_box_changed(
            self, index, exposure, exposure_combo_box, edit_button):
        """Action when classification combo box changed.

        :param index: The index of the combo box.
        :type index: int

        :param exposure: The exposure associated with the combo box.
        :type exposure: dict

        :param exposure_combo_box: Combo box for the classification.
        :type exposure_combo_box: QComboBox

        :param edit_button: The edit button associate with combo box.
        :type edit_button: QPushButton
        """
        # Disable button if it's no classification
        edit_button.setEnabled(bool(index))

        classification = self.get_classification(exposure_combo_box)
        self.activate_classification(exposure, classification)
        clear_layout(self.right_layout)
        self.show_current_state()

        self.parent.pbnNext.setEnabled(self.is_ready_to_next_step())

        # Open edit panel directly
        edit_button.click()
Action when classification combo box changed.

        :param index: The index of the combo box.
        :type index: int

        :param exposure: The exposure associated with the combo box.
        :type exposure: dict

        :param exposure_combo_box: Combo box for the classification.
        :type exposure_combo_box: QComboBox

        :param edit_button: The edit button associate with combo box.
        :type edit_button: QPushButton