Issue #3166744: Views override

src/RowFieldset.php

@@ -105,9 +105,8 @@ class RowFieldset {
         }
       }
     }
-    // @todo Theme hook suggestions!
     $element = [
-      '#theme' => 'views_fieldsets_' . $this->getWrapperType(),
+      '#theme' => $this->themeFunctions($this->getWrapperType()),
       '#fields' => $this->children,
       '#show_fieldset' => $show_fieldset,
       '#legend' => Markup::create($this->getLegend()),
@@ -176,4 +175,39 @@ class RowFieldset {
     $this->children[$field_name] = $fields[$field_name];
   }
 
+  /**
+   * Generate a list of theme hook suggestions.
+   *
+   * @param string $type
+   *   Fieldset type.
+   *
+   * @return array
+   *   List of theme suggestions.
+   */
+  public function themeFunctions(string $type): array {
+    $themes = [];
+    $hook = 'views_fieldsets_' . $type;
+
+    $display = $this->handler->view->display_handler->display;
+
+    if (!empty($display)) {
+      $themes[] = $hook . '__' . $this->handler->view->storage->id() . '__' . $display['id'] . '__' . $this->handler->options['id'];
+      $themes[] = $hook . '__' . $this->handler->view->storage->id() . '__' . $display['id'];
+      $themes[] = $hook . '__' . $display['id'] . '__' . $this->handler->options['id'];
+      $themes[] = $hook . '__' . $display['id'];
+      if ($display['id'] != $display['display_plugin']) {
+        $themes[] = $hook . '__' . $this->handler->view->storage->id() . '__' . $display['display_plugin'] . '__' . $this->handler->options['id'];
+        $themes[] = $hook . '__' . $this->handler->view->storage->id() . '__' . $display['display_plugin'];
+        $themes[] = $hook . '__' . $display['display_plugin'] . '__' . $this->handler->options['id'];
+        $themes[] = $hook . '__' . $display['display_plugin'];
+      }
+    }
+    $themes[] = $hook . '__' . $this->handler->view->storage->id() . '__' . $this->handler->options['id'];
+    $themes[] = $hook . '__' . $this->handler->view->storage->id();
+    $themes[] = $hook . '__' . $this->handler->options['id'];
+    $themes[] = $hook;
+
+    return $themes;
+  }
+
 }

views_fieldsets.module

@@ -245,3 +245,18 @@ function views_fieldsets_views_ui_rearrange_form_submit($form, $form_state) {
   $display->setOption('fields', $display_fields);
   $ui_view->cacheSet();
 }
+
+/**
+ * Implements hook_theme_suggestions_HOOK().
+ */
+function views_fieldsets_theme_suggestions_paragraph(array $variables) {
+  $suggestions = [];
+  $paragraph = $variables['elements']['#paragraph'];
+  $sanitized_view_mode = strtr($variables['elements']['#view_mode'], '.', '_');
+
+  $suggestions[] = 'paragraph__' . $sanitized_view_mode;
+  $suggestions[] = 'paragraph__' . $paragraph->bundle();
+  $suggestions[] = 'paragraph__' . $paragraph->bundle() . '__' . $sanitized_view_mode;
+
+  return $suggestions;
+}