private void notifySourcepathChanged() {
   ArrayList<SourceListener> l = new ArrayList<SourceListener>(sourceListeners);
   SourcepathChangedEvent evt = new SourcepathChangedEvent(this);
   for (int i = 0; i < l.size(); i++) {
     l.get(i).sourcepathChanged(evt);
   }
 }
 public void removeSourceListener(SourceListener l) {
   sourceListeners.remove(l);
 }
 public void addSourceListener(SourceListener l) {
   sourceListeners.add(l);
 }