commit f71dfa9b69c44664cade38d0048373f409849f0c
Author: Erik Stielstra <info@erikstielstra.nl>
Date:   Fri Oct 21 18:12:50 2016 +0200

    Issue 2461695-72

diff --git a/src/Plugin/Field/FieldWidget/InlineParagraphsWidget.php b/src/Plugin/Field/FieldWidget/InlineParagraphsWidget.php
index 25efb48..f462c04 100644
--- a/src/Plugin/Field/FieldWidget/InlineParagraphsWidget.php
+++ b/src/Plugin/Field/FieldWidget/InlineParagraphsWidget.php
@@ -16,6 +16,7 @@ use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Render\Element;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\paragraphs;
+use Drupal\paragraphs\Entity\Paragraph;
 use Symfony\Component\Validator\ConstraintViolationInterface;
 
 
@@ -167,7 +168,6 @@ class InlineParagraphsWidget extends WidgetBase {
     $parents = $element['#field_parents'];
 
     $paragraphs_entity = NULL;
-    $host = $items->getEntity();
     $widget_state = static::getWidgetState($parents, $field_name, $form_state);
 
     $entity_manager = \Drupal::entityTypeManager();
@@ -216,61 +216,7 @@ class InlineParagraphsWidget extends WidgetBase {
     }
 
     if ($paragraphs_entity) {
-      // Detect if we are translating.
-      $this->initIsTranslating($form_state, $host);
-      $langcode = $form_state->get('langcode');
-
-      if (!$this->isTranslating) {
-        // Set the langcode if we are not translating.
-        if ($paragraphs_entity->get('langcode') != $langcode) {
-          // If a translation in the given language already exists, switch to
-          // that. If there is none yet, update the language.
-          if ($paragraphs_entity->hasTranslation($langcode)) {
-            $paragraphs_entity = $paragraphs_entity->getTranslation($langcode);
-          }
-          else {
-            $paragraphs_entity->set('langcode', $langcode);
-          }
-        }
-      }
-
-      // Localised Paragraphs.
-      //  If the parent field is marked as translatable, assume paragraphs
-      //  to be localized (host entity expects different paragraphs for
-      //  different languages)
-      elseif ($items->getFieldDefinition()->isTranslatable()) {
-        $paragraphs_entity = $this->cloneReferencedEntity($paragraphs_entity, $langcode);
-      }
-
-      // Translated Paragraphs
-      //  If the parent field is not translatable, assume the paragraph
-      //  entity itself (rather the fields within it) are marked as
-      //  translatable. (host entity expects same paragraphs in different
-      //  languages).
-      else {
-        // Add translation if missing for the target language.
-        if (!$paragraphs_entity->hasTranslation($langcode)) {
-          // Get the selected translation of the paragraph entity.
-          $entity_langcode = $paragraphs_entity->language()->getId();
-          $source = $form_state->get(['content_translation', 'source']);
-          $source_langcode = $source ? $source->getId() : $entity_langcode;
-          $paragraphs_entity = $paragraphs_entity->getTranslation($source_langcode);
-          // The paragraphs entity has no content translation source field if
-          // no paragraph entity field is translatable, even if the host is.
-          if ($paragraphs_entity->hasField('content_translation_source')) {
-            // Initialise the translation with source language values.
-            $paragraphs_entity->addTranslation($langcode, $paragraphs_entity->toArray());
-            $translation = $paragraphs_entity->getTranslation($langcode);
-            $manager = \Drupal::service('content_translation.manager');
-            $manager->getTranslationMetadata($translation)->setSource($paragraphs_entity->language()->getId());
-          }
-        }
-        // If any paragraphs type is translatable do not switch.
-        if ($paragraphs_entity->hasField('content_translation_source')) {
-          // Switch the paragraph to the translation.
-          $paragraphs_entity = $paragraphs_entity->getTranslation($langcode);
-        }
-      }
+      $paragraphs_entity = $this->prepareEntity($paragraphs_entity, $items, $form_state);
 
       $element_parents = $parents;
       $element_parents[] = $field_name;
@@ -1137,6 +1083,82 @@ class InlineParagraphsWidget extends WidgetBase {
   }
 
   /**
+   * Prepares the paragraph entity for translation.
+   *
+   * @param \Drupal\paragraphs\Entity\Paragraph $entity
+   *   The paragraph entity.
+   * @param \Drupal\Core\Field\FieldItemListInterface $items
+   *   The field items list that hosts this paragraph.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   *
+   * @return \Drupal\paragraphs\Entity\Paragraph
+   *   The prepared paragraph.
+   *
+   * @see \Drupal\Core\Entity\ContentEntityForm::initFormLangcodes().
+   */
+  protected function prepareEntity(Paragraph $entity, FieldItemListInterface $items, FormStateInterface $form_state) {
+    // Detect if we are translating.
+    $this->initIsTranslating($form_state, $items->getEntity());
+    $langcode = $form_state->get('langcode');
+
+    if (!$this->isTranslating) {
+      // Set the langcode if we are not translating.
+      if ($entity->get('langcode') != $langcode) {
+        // If a translation in the given language already exists, switch to
+        // that. If there is none yet, update the language.
+        if ($entity->hasTranslation($langcode)) {
+          $entity = $entity->getTranslation($langcode);
+        }
+        else {
+          $entity->set('langcode', $langcode);
+        }
+      }
+    }
+
+    // Localised Paragraphs.
+    //  If the parent field is marked as translatable, assume paragraphs
+    //  to be localized (host entity expects different paragraphs for
+    //  different languages)
+    elseif ($items->getFieldDefinition()->isTranslatable()) {
+      $entity = $this->cloneReferencedEntity($entity, $langcode);
+    }
+
+    // Translated Paragraphs
+    //  If the parent field is not translatable, assume the paragraph
+    //  entity itself (rather the fields within it) are marked as
+    //  translatable. (host entity expects same paragraphs in different
+    //  languages).
+    else {
+      // Add translation if missing for the target language.
+      if (!$entity->hasTranslation($langcode)) {
+        // Get the selected translation of the paragraph entity.
+        $entity_langcode = $entity->language()->getId();
+        $source = $form_state->get(['content_translation', 'source']);
+        $source_langcode = $source ? $source->getId() : $entity_langcode;
+        $entity = $entity->getTranslation($source_langcode);
+        // The paragraphs entity has no content translation source field if
+        // no paragraph entity field is translatable, even if the host is.
+        if ($entity->hasField('content_translation_source')) {
+          // Initialise the translation with source language values.
+          $entity->addTranslation($langcode, $entity->toArray());
+          $translation = $entity->getTranslation($langcode);
+          $manager = \Drupal::service('content_translation.manager');
+          $manager->getTranslationMetadata($translation)
+            ->setSource($entity->language()->getId());
+        }
+      }
+      // If any paragraphs type is translatable do not switch.
+      if ($entity->hasField('content_translation_source')) {
+        // Switch the paragraph to the translation.
+        $entity = $entity->getTranslation($langcode);
+      }
+    }
+
+    return $entity;
+  }
+
+/**
    * Initializes the translation form state.
    *
    * @param \Drupal\Core\Form\FormStateInterface $form_state
@@ -1262,4 +1284,4 @@ class InlineParagraphsWidget extends WidgetBase {
     // default?
     return in_array($entity_type_id, ['field_collection_item', 'paragraph']);
   }
-}
\ No newline at end of file
+}