interface FieldTranslationSynchronizerInterface

interface FieldTranslationSynchronizerInterface {
    
    /**
     * Performs field column synchronization on the given entity.
     *
     * Field column synchronization takes care of propagating any change in the
     * field items order and in the column values themselves to all the available
     * translations. This functionality is provided by defining a
     * 'translation_sync' key for the 'content_translation' module's portion of
     * the field definition's 'third_party_settings', holding an array of
     * column names to be synchronized. The synchronized column values are shared
     * across translations, while the rest varies per-language. This is useful for
     * instance to translate the "alt" and "title" textual elements of an image
     * field, while keeping the same image on every translation.
     *
     * @param \Drupal\Core\Entity\ContentEntityInterface $entity
     *   The entity whose values should be synchronized.
     * @param string $sync_langcode
     *   The language of the translation whose values should be used as source for
     *   synchronization.
     * @param string $original_langcode
     *   (optional) If a new translation is being created, this should be the
     *   language code of the original values. Defaults to NULL.
     */
    public function synchronizeFields(ContentEntityInterface $entity, $sync_langcode, $original_langcode = NULL);
    
    /**
     * Synchronize the items of a single field.
     *
     * All the column values of the "active" language are compared to the
     * unchanged values to detect any addition, removal or change in the items
     * order. Subsequently the detected changes are performed on the field items
     * in other available languages.
     *
     * @param array $field_values
     *   The field values to be synchronized.
     * @param array $unchanged_items
     *   The unchanged items to be used to detect changes.
     * @param string $sync_langcode
     *   The language code of the items to use as source values.
     * @param array $translations
     *   An array of all the available language codes for the given field.
     * @param array $properties
     *   An array of property names to be synchronized.
     */
    public function synchronizeItems(array &$field_values, array $unchanged_items, $sync_langcode, array $translations, array $properties);
    
    /**
     * Returns the synchronized properties for the specified field definition.
     *
     * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
     *   A field definition.
     *
     * @return string[]
     *   An array of synchronized field property names.
     */
    public function getFieldSynchronizedProperties(FieldDefinitionInterface $field_definition);

}