@Override
        public void actionPerformed(ActionEvent e) {
          if (getCheckboxColumn() == -1) return;

          int[] selectedRows = myEntryTable.getSelectedRows();
          boolean currentlyMarked = true;
          for (int selectedRow : selectedRows) {
            if (selectedRow < 0 || !myEntryTable.isCellEditable(selectedRow, getCheckboxColumn())) {
              return;
            }
            currentlyMarked &= ((Boolean)myEntryTable.getValueAt(selectedRow, getCheckboxColumn())).booleanValue();
          }
          for (int selectedRow : selectedRows) {
            myEntryTable.setValueAt(currentlyMarked ? Boolean.FALSE : Boolean.TRUE, selectedRow, getCheckboxColumn());
          }
        }
@Override
        public void actionPerformed(ActionEvent e)