public void mouseClicked(MouseEvent e) {
      JTableHeader h = (JTableHeader) e.getSource();
      TableColumnModel columnModel = h.getColumnModel();
      int viewColumn = columnModel.getColumnIndexAtX(e.getX());
      int column = columnModel.getColumn(viewColumn).getModelIndex();
      if (column != -1) {
        sorting_column = column;

        // 0 == priority icon column
        // 4 == priority text column
        if (column == 0) sorting_column = 4;

        if (e.isControlDown()) sorting_column = -1;
        else opposite = !opposite;

        TaskTable treetable = ((TaskTable) h.getTable());

        // java.util.Collection expanded = treetable.getExpandedTreeNodes();

        treetable.tableChanged();
        // treetable.setExpandedTreeNodes(expanded);
        // h.updateUI();
        h.resizeAndRepaint();
      }
    }
 public TaskTableSorter(TaskTable table) {
   JTableHeader tableHeader = table.getTableHeader();
   tableHeader.addMouseListener(new MouseHandler());
   tableHeader.setDefaultRenderer(new SortableHeaderRenderer());
 }