code: @Override
      public void onAutoHide() {
          DatePicker datePicker = (DatePicker) getControl();
          JFXDatePickerSkin cpSkin = (JFXDatePickerSkin) datePicker.getSkin();
          cpSkin.syncWithAutoUpdate();
          if (!datePicker.isShowing()) {
              super.onAutoHide();
          }
      }
docs: ************************************************************************
  *
  Mouse Events handling (when losing focus)                              *
  *
  ***********************************************************************