public function flagErrors(FieldItemListInterface $items, ConstraintViolationListInterface $violations, array $form, FormStateInterface $form_state) {
$field_name = $this->fieldDefinition
->getName();
$field_state = static::getWidgetState($form['#parents'], $field_name, $form_state);
// In dragdrop mode, validation errors can not be mapped to form elements,
// add them on the top level widget element.
if (!empty($field_state['dragdrop'])) {
if ($violations
->count()) {
$element = NestedArray::getValue($form_state
->getCompleteForm(), $field_state['array_parents']);
foreach ($violations as $violation) {
$form_state
->setError($element, $violation
->getMessage());
}
}
}
else {
return parent::flagErrors($items, $violations, $form, $form_state);
}
}