/** Reaction to Add/Delete buttons. */
 public void actionPerformed(ActionEvent e) {
   String cmd = e.getActionCommand();
   if (cmdAdd.equals(cmd)) {
     Zone z = ((ControllerSWARM) controller).new Zone();
     Vector<AbstractNetworkElement> ml =
         ((AbstractControllerComplex) controller).getMyMonitor().getPredecessors();
     Vector<AbstractNetworkElement> cl =
         ((AbstractControllerComplex) controller).getMyMonitor().getSuccessors();
     if (ml.size() > 0) z.bottleneck = (AbstractLinkHWC) ml.firstElement();
     if (cl.size() > 0) {
       z.setFromOnramp((AbstractLinkHWC) cl.firstElement());
       z.setToOnramp((AbstractLinkHWC) cl.firstElement());
     }
     z.initialize();
     zones.add(z);
     zoneTM.fireTableStructureChanged();
     setUpBottleneckColumn();
     setUpFromOnrampColumn();
     setUpToOnrampColumn();
   }
   if (cmdDelete.equals(cmd)) {
     try {
       int[] selected = zonetab.getSelectedRows();
       if ((selected != null) && (selected.length > 0))
         for (int i = 0; i < selected.length; i++) {
           int idx = selected[i] - i;
           if ((idx >= 0) && (idx < zones.size())) {
             zones.remove(idx);
             zoneTM.fireTableStructureChanged();
             setUpBottleneckColumn();
             setUpFromOnrampColumn();
             setUpToOnrampColumn();
           }
         }
     } catch (Exception ex) {
     }
   }
   return;
 }
 /** Reaction to buttons and combo boxes. */
 public void actionPerformed(ActionEvent e) {
   String cmd = e.getActionCommand();
   if (cmdCtrlProp.equals(cmd)) {
     try {
       Class c =
           Class.forName("aurora.hwc.control.Panel" + myController.getClass().getSimpleName());
       AbstractPanelController cp = (AbstractPanelController) c.newInstance();
       cp.initialize(myController, null);
     } catch (Exception ex) {
     }
   }
   if (cmdCtrlList.equals(cmd)) {
     JComboBox cb = (JComboBox) e.getSource();
     if (cb.getSelectedIndex() > 0) {
       myController = (AbstractControllerComplex) listCControllers.getSelectedItem();
       buttonProp.setEnabled(true);
     } else {
       buttonProp.setEnabled(false);
       myController = null;
     }
     myMonitor.setMyController(myController);
   }
   return;
 }