/**
  * Find the class for the projection
  *
  * @param proj projection
  * @return corresponding ProjectionClass (or null if not found)
  */
 private ProjectionClass findProjectionClass(Projection proj) {
   Class want = proj.getClass();
   ComboBoxModel projClassList = projClassCB.getModel();
   for (int i = 0; i < projClassList.getSize(); i++) {
     ProjectionClass pc = (ProjectionClass) projClassList.getElementAt(i);
     if (want.equals(pc.projClass)) {
       return pc;
     }
   }
   return null;
 }
 private Object lookupItem(String pattern) {
   Object selectedItem = model.getSelectedItem();
   // only search for a different item if the currently selected does not match
   if (selectedItem != null && startsWithIgnoreCase(selectedItem.toString(), pattern)) {
     return selectedItem;
   } else {
     // iterate over all items
     for (int i = 0, n = model.getSize(); i < n; i++) {
       Object currentItem = model.getElementAt(i);
       // current item starts with the pattern?
       if (currentItem != null && startsWithIgnoreCase(currentItem.toString(), pattern)) {
         return currentItem;
       }
     }
   }
   // no item starts with the pattern => return null
   return null;
 }