@Override
 public void selectionChanged(IFormPart masterPart, ISelection selection) {
   IStructuredSelection ssel = (IStructuredSelection) selection;
   if (ssel.size() == 1) {
     fInput = (IPluginExtensionPoint) ssel.getFirstElement();
   } else fInput = null;
   update();
 }
 /** Tests if the current workbench selection is a suitable container to use. */
 private void initialize() {
   if (selection != null
       && selection.isEmpty() == false
       && selection instanceof IStructuredSelection) {
     IStructuredSelection ssel = (IStructuredSelection) selection;
     if (ssel.size() > 1) {
       return;
     }
     Object obj = ssel.getFirstElement();
     if (obj instanceof IResource) {
       IContainer container;
       if (obj instanceof IContainer) {
         container = (IContainer) obj;
       } else {
         container = ((IResource) obj).getParent();
       }
       containerText.setText(container.getFullPath().toString());
     }
   }
   fileText.setText("new.gaml");
 }