Make it possible to alter the rendered editor.

src/Controller/EditorController.php

@@ -3,10 +3,8 @@
 namespace Drupal\image_canvas_editor_api\Controller;
 
 use Drupal\Core\Controller\ControllerBase;
-use Drupal\Core\Datetime\DateFormatterInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\Url;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\image_canvas_editor_api\Plugin\EditorPluginManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\JsonResponse;
@@ -28,13 +26,11 @@ class EditorController extends ControllerBase {
 
   /**
    * Constructs the controller object.
-   *
-   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
-   *   The date formatter service.
    */
-  public function __construct(EntityTypeManagerInterface $entity_manager, EditorPluginManager $manager) {
+  public function __construct(EntityTypeManagerInterface $entity_manager, EditorPluginManager $manager, ModuleHandlerInterface $module_handler) {
     $this->entityTypeManager = $entity_manager;
     $this->pluginManager = $manager;
+    $this->moduleHandler = $module_handler;
   }
 
   /**
@@ -43,7 +39,8 @@ class EditorController extends ControllerBase {
   public static function create(ContainerInterface $container) {
     return new static(
       $container->get('entity_type.manager'),
-      $container->get('plugin.manager.image_editor_plugin')
+      $container->get('plugin.manager.image_editor_plugin'),
+      $container->get('module_handler')
     );
   }
 
@@ -75,7 +72,9 @@ class EditorController extends ControllerBase {
     /** @var \Drupal\file\Entity\File $file */
     $image_url = file_create_url($file->getFileUri());
 
-    $build['editor'] = $instance->renderEditor($image_url);
+    $editor = $instance->renderEditor($image_url);
+    $this->moduleHandler->alter('image_canvas_editor_api_editor_render', $editor);
+    $build['editor'] = $editor;
     $build['save'] = [
       '#type' => 'inline_template',
       '#template' => '<button class="btn button image-canvas-editor-save">{{ save }}</button>',