popupContent = new PVerticalPanel();
popupContent.add(new PLabel("from"));
popupContent.add(from.render().asWidget());
popupContent.add(new PLabel("to"));
popupContent.add(to.render().asWidget());
final PKeyUpFilterHandler handler = new PKeyUpFilterHandler(PKeyCodes.ENTER) {
@Override
public void onKeyUp(final PKeyUpEvent keyUpEvent) {
final RefreshListEvent refreshListEvent = new RefreshListEvent(this, from);
eventBus.fireEvent(refreshListEvent);