private void changeOperationForSelection() {
   for (int row : myTable.getSelectedRows()) {
     if (row != -1) {
       final DirDiffElementImpl element = myModel.getElementAt(row);
       if (element != null) {
         element.setNextOperation();
         myModel.fireTableRowsUpdated(row, row);
       }
     }
   }
 }