docs: @Override
      public void areaSelected(Area area)
      {
          //show the separator list
          if (area instanceof AreaImpl)
          {
              SeparatorSet sset = Config.createSeparators((AreaImpl) area);
              DefaultListModel<Separator> ml = new DefaultListModel<Separator>();
              for (Separator sep : sset.getHorizontal())
                  ml.addElement(sep);
              for (Separator sep : sset.getVertical())
                  ml.addElement(sep);
              for (Separator sep : sset.getBoxsep())
                  ml.addElement(sep);
              sepList.setModel(ml);
          }
          else
          {
              //not a grouping area -- no separators
              sepList.setModel(new DefaultListModel<Separator>());
          }
      }