private Row[] getViewToModel() {
    if (viewToModel == null) {
      int tableModelRowCount = tableModel.getRowCount();
      viewToModel = new Row[tableModelRowCount];
      for (int row = 0; row < tableModelRowCount; row++) {
        viewToModel[row] = new Row(row);
      }

      if (isSorting()) {
        Arrays.sort(viewToModel);
      }
    }
    return viewToModel;
  }
 public int getRowCount() {
   return (tableModel == null) ? 0 : tableModel.getRowCount();
 }