--- /dev/null
+<?php
+
+namespace Drupal\image\Form;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\image\ImageEffectManager;
+use Drupal\image\ImageStyleInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides an add form for image effects.
+ */
+class ImageEffectAddForm extends ImageEffectFormBase {
+
+ /**
+ * The image effect manager.
+ *
+ * @var \Drupal\image\ImageEffectManager
+ */
+ protected $effectManager;
+
+ /**
+ * Constructs a new ImageEffectAddForm.
+ *
+ * @param \Drupal\image\ImageEffectManager $effect_manager
+ * The image effect manager.
+ */
+ public function __construct(ImageEffectManager $effect_manager) {
+ $this->effectManager = $effect_manager;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container) {
+ return new static(
+ $container->get('plugin.manager.image.effect')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state, ImageStyleInterface $image_style = NULL, $image_effect = NULL) {
+ $form = parent::buildForm($form, $form_state, $image_style, $image_effect);
+
+ $form['#title'] = $this->t('Add %label effect', ['%label' => $this->imageEffect->label()]);
+ $form['actions']['submit']['#value'] = $this->t('Add effect');
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function prepareImageEffect($image_effect) {
+ $image_effect = $this->effectManager->createInstance($image_effect);
+ // Set the initial weight so this effect comes last.
+ $image_effect->setWeight(count($this->imageStyle->getEffects()));
+ return $image_effect;
+ }
+
+}