protected Component createSearchField() {
final TextField searchField = new TextField("Search: ", "search");
searchField.setSelectOnFocus(true);
searchField.setAutoWidth(true);
searchField.setEmptyText("Type search string");
searchField.addListener(new TextFieldListenerAdapter() {
@Override
public void onSpecialKey(final Field field, final EventObject e) {
if (e.getKey() == EventObject.ENTER) {
SearchUtil searchUtil = new SearchUtil(getProjectId(), ClassTreePortlet.this, getSearchAsyncCallback());
searchUtil.setBusyComponent(searchField);