code: def cancel_button_clicked(self):
          
          # Change mode
          self.mode = CHOOSE_MODE
          # Enable all edit buttons and combo boxes
          for i in range(len(self.exposures)):
              if i == self.special_case_index:
                  self.exposure_edit_buttons[i].setEnabled(False)
                  self.exposure_combo_boxes[i].setEnabled(False)
                  continue
              if self.get_classification(self.exposure_combo_boxes[i]):
                  self.exposure_edit_buttons[i].setEnabled(True)
              else:
                  self.exposure_edit_buttons[i].setEnabled(False)
              # self.exposure_edit_buttons[i].setText(tr('Edit'))
              self.exposure_combo_boxes[i].setEnabled(True)
  
          # Clear right panel
          clear_layout(self.right_layout)
          # Show current state
          self.show_current_state()
          # Unset active exposure
          self.active_exposure = None
  
          self.parent.pbnNext.setEnabled(self.is_ready_to_next_step())
docs: Action for cancel button clicked.