repaint();
if (getColumnCount() < 2) return;  int x0 = 0;  int idx0 = event.getFirstIndex(); int idxn = event.getLastIndex(); int i;  for (i = 0; i < idx0; i++) x0 += columnModel.getColumn(i).getWidth();  int xn = x0;  for (i = idx0; i <= idxn; i++) xn += columnModel.getColumn(i).getWidth();  repaint(x0, 0, xn-x0, getHeight());
  public void columnSelectionChanged (ListSelectionEvent event)  {    repaint();  }