Render non-browser-native images in gallery

We'll include these in the gallery when we have thumbnails for them and
they're of an image/* mimetype, but they're not in the whitelist as
being browser-supported; these will get rendered by showing the "large"
thumbnail image.

Alongside this there's some cleanup/refactoring to the lightgallery
helper, and a change to the gallery block for media to make it only use
the gallery when the gallery supports the media being viewed, otherwise
falling back to the standard embed.

(fix #2068)

application/src/View/Helper/LightGalleryOutput.php

@@ -25,15 +25,16 @@ public function __invoke($files = null)
         $mediaCaption = $view->themeSetting('media_caption');
 
         foreach ($files as $file) {
+            $attribs = [];
             $media = $file['media'];
-            $source = ($media->originalUrl()) ? $media->originalUrl() : $media->source();
-            $mediaCaptionOptions = [
-                'none' => '',
-                'title' => 'data-sub-html="' . $media->displayTitle() . '"',
-                'description' => 'data-sub-html="' . $media->displayDescription() . '"',
-            ];
-            $mediaCaptionAttribute = ($mediaCaption) ? $mediaCaptionOptions[$mediaCaption] : '';
-            $mediaType = $media->mediatype();
+            if (!empty($file['forceThumbnail'])) {
+                $source = $media->thumbnailUrl('large');
+                $downloadUrl = $media->originalUrl() ?: $source;
+            } else {
+                $source = $downloadUrl = $media->originalUrl() ?: $media->source();
+            }
+
+            $mediaType = $media->mediaType();
             if (null !== $mediaType && strpos($mediaType, 'video') !== false) {
                 $videoSrcObject = [
                     'source' => [
@@ -60,14 +61,35 @@ public function __invoke($files = null)
                     }
                 }
                 $videoSrcJson = json_encode($videoSrcObject);
-                $html .= '<div data-video="' . $escape($videoSrcJson) . '" ' . $mediaCaptionAttribute . 'data-thumb="' . $escape($media->thumbnailUrl('medium')) . '" data-download-url="' . $source . '" class="media resource">';
+                $attribs['data-video'] = $videoSrcJson;
             } elseif ($mediaType == 'application/pdf') {
-                $html .= '<div data-iframe="' . $escape($source) . '" ' . $mediaCaptionAttribute . 'data-src="' . $source . '" data-thumb="' . $escape($media->thumbnailUrl('medium')) . '" data-download-url="' . $source . '" class="media resource">';
+                $attribs['data-iframe'] = $source;
+                $attribs['data-src'] = $source;
             } else {
-                $html .= '<div data-src="' . $source . '" ' . $mediaCaptionAttribute . 'data-thumb="' . $escape($media->thumbnailUrl('medium')) . '" data-download-url="' . $source . '" class="media resource">';
+                $attribs['data-src'] = $source;
+            }
+
+            switch ($mediaCaption) {
+                case 'title':
+                    $attribs['data-sub-html'] = $media->displayTitle();
+                    break;
+                case 'description':
+                    $attribs['data-sub-html'] = $media->displayDescription();
+                    break;
+                case 'none':
+                default:
+                    // no action
+            }
+
+            $attribs['data-thumb'] = $media->thumbnailDisplayUrl('medium');
+            $attribs['data-download-url'] = $downloadUrl;
+            $attribs['class'] = 'media resource';
+
+            $html .= '<div';
+            foreach ($attribs as $attribName => $attribValue) {
+                $html .= ' ' . $attribName . '="' . $escape($attribValue) . '"';
             }
-            $html .= $media->render();
-            $html .= '</div>';
+            $html .= '></div>';
         }
         $html .= '</div>';
 

application/src/View/Helper/SortMedia.php

@@ -9,7 +9,7 @@ public function __invoke($files = null)
     {
         $sortedMedia = [];
         $whitelist = ['image/bmp', 'image/gif', 'image/jpeg', 'image/png', 'image/svg+xml', 'image/webp', 'video/flv', 'video/x-flv', 'video/mp4', 'video/m4v',
-                    'video/webm', 'video/wmv', 'video/quicktime', 'application/pdf', ];
+            'video/webm', 'video/wmv', 'video/quicktime', 'application/pdf', ];
         $html5videos = [];
         $mediaCount = 0;
 
@@ -23,6 +23,10 @@ public function __invoke($files = null)
                     $sortedMedia['lightMedia'][$mediaCount]['tracks'] = [];
                 }
                 $mediaCount++;
+            } elseif (strpos($mediaType ?? '', 'image/') === 0 && $media->hasThumbnails()) {
+                $sortedMedia['lightMedia'][$mediaCount]['media'] = $media;
+                $sortedMedia['lightMedia'][$mediaCount]['forceThumbnail'] = true;
+                $mediaCount++;
             } else {
                 $sortedMedia['otherMedia'][] = $media;
             }

application/view/common/resource-page-block-layout/lightbox-gallery-media.phtml

@@ -1,5 +1,9 @@
 <?php
 $media = $resource;
-$mediaType = $media->mediaType();
-?>
-<?php echo $this->lightGalleryOutput([['media' => $media]]); ?>
+$sortedMedia = $this->sortMedia([$media]);
+
+if (isset($sortedMedia['lightMedia'])):
+    echo $this->lightGalleryOutput($sortedMedia['lightMedia']);
+else:
+    echo $this->partial('common/resource-page-block-layout/media-render');
+endif;