fix deprecated code

Closes #3074366

src/Plugin/CKEditorPlugin/Detail.php

@@ -4,6 +4,8 @@ namespace Drupal\lucidutil\Plugin\CKEditorPlugin;
 
 use Drupal\ckeditor\CKEditorPluginBase;
 use Drupal\editor\Entity\Editor;
+use Drupal\Core\Extension\ModuleExtensionList;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Defines the "detail" plugin.
@@ -19,6 +21,30 @@ use Drupal\editor\Entity\Editor;
  */
 class Detail extends CKEditorPluginBase {
 
+  /**
+   * Provides a list of available modules.
+   *
+   * @var \Drupal\Core\Extension\ModuleExtensionList
+   */
+  protected $service;
+
+  /**
+   * Class constructor.
+   */
+  public function __construct(ModuleExtensionList $service) {
+    $this->service = $service;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    // Instantiates this form class.
+    return new static(
+      // Load the service required to construct this class.
+      $container->get('extension.list.module')
+    );
+  }
 
   /**
    * {@inheritdoc}
@@ -33,7 +59,7 @@ class Detail extends CKEditorPluginBase {
     return [
       'Detail' => [
         'label' => t('Detail'),
-        'image' => drupal_get_path('module', 'lucidutil') . '/js/plugins/detail/icons/detail.png',
+        'image' => $this->service->getPath('lucidutil') . '/js/plugins/detail/icons/detail.png',
       ],
     ];
   }
@@ -44,7 +70,7 @@ class Detail extends CKEditorPluginBase {
   public function getFile() {
     // Make sure that the path to the plugin.js matches the file structure of
     // the CKEditor plugin you are implementing.
-    return drupal_get_path('module', 'lucidutil') . '/js/plugins/detail/plugin.js';
+    return $this->service->getPath('lucidutil') . '/js/plugins/detail/plugin.js';
   }
 
   /**