Resolve #3195407 "Add support for Responsive Image module"

Closes #3195407

src/Plugin/Field/FieldFormatter/ResponsiveImageCaptionFormatter.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\image_field_caption\Plugin\Field\FieldFormatter\ResponsiveImageCaptionFormatter.
+ */
+
+namespace Drupal\image_field_caption\Plugin\Field\FieldFormatter;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\responsive_image\Plugin\Field\FieldFormatter\ResponsiveImageFormatter;
+
+/**
+ * Plugin implementation of the 'responsive_image_caption' formatter.
+ *
+ * @FieldFormatter(
+ *   id = "responsive_image_caption",
+ *   label = @Translation("Responsive Image with caption"),
+ *   field_types = {
+ *     "image"
+ *   }
+ * )
+ */
+class ResponsiveImageCaptionFormatter extends ResponsiveImageFormatter {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function viewElements(FieldItemListInterface $items, $langcode) {
+    $elements = parent::viewElements($items, $langcode);
+    foreach ($elements as $delta => $element) {
+      // Set a new theme callback function for the responsive image caption formatter.
+      $elements[$delta]['#theme'] = 'responsive_image_caption_formatter';
+    }
+    return $elements;
+  }
+}