code: public void showValidationFailureIcon(final String validationMessage) {
          validationIcon.setValue(FontAwesome.TIMES_CIRCLE.getHtml());
          validationIcon.setStyleName(SPUIStyleDefinitions.ERROR_ICON);
          validationIcon.setDescription(validationMessage);
          filterManagementUIState.setFilterQueryValue(null);
          filterManagementUIState.setIsFilterByInvalidFilterQuery(Boolean.TRUE);
      }
docs: Shows the validation error icon in the textfield
  
  @param validationMessage
  the validation message which should be added to the error-icon
  tooltip