@Override
    public void actionPerformed(final ActionEvent e){
      final int rowCount=getRowCount();
      LOG.assertTrue(rowCount>0);
      final int selectedRow=(getSelectedRow()+1)%rowCount;
      if(isEditing()){
        finishEditing();
        getSelectionModel().setSelectionInterval(selectedRow,selectedRow);
        scrollRectToVisible(getCellRect(selectedRow, 0, true));
        startEditing(selectedRow);
      }else{
        getSelectionModel().setSelectionInterval(selectedRow,selectedRow);
        scrollRectToVisible(getCellRect(selectedRow, 0, true));
      }
    }
@Override
    public void actionPerformed(final ActionEvent e)