code: def on_tblFunctions1_itemSelectionChanged(self):
          
          # Clear the selection on the 2nd matrix
          self.parent.step_fc_functions2.tblFunctions2.clearContents()
          self.parent.step_fc_functions2.lblAvailableFunctions2.clear()
          self.parent.pbnNext.setEnabled(True)
  
          # Put a dot to the selected cell - note there is no way
          # to center an icon without using a custom ItemDelegate
          selection = self.tblFunctions1.selectedItems()
          selItem = (len(selection) == 1) and selection[0] or None
          for row in range(self.tblFunctions1.rowCount()):
              for column in range(self.tblFunctions1.columnCount()):
                  item = self.tblFunctions1.item(row, column)
                  item.setText((item == selItem) and '•' or '')
docs: Choose selected hazard x exposure combination.
  
          .. note:: This is an automatic Qt slot
             executed when the category selection changes.