class ImageEffectDeleteForm

class ImageEffectDeleteForm extends ConfirmFormBase {
  
  /**
   * The image style containing the image effect to be deleted.
   *
   * @var \Drupal\image\ImageStyleInterface
   */
  protected $imageStyle;
  
  /**
   * The image effect to be deleted.
   *
   * @var \Drupal\image\ImageEffectInterface
   */
  protected $imageEffect;
  
  /**
   * {@inheritdoc}
   */
  public function getQuestion() {
    return $this->t('Are you sure you want to delete the @effect effect from the %style style?', [
      '%style' => $this->imageStyle
        ->label(),
      '@effect' => $this->imageEffect
        ->label(),
    ]);
  }
  
  /**
   * {@inheritdoc}
   */
  public function getConfirmText() {
    return $this->t('Delete');
  }
  
  /**
   * {@inheritdoc}
   */
  public function getCancelUrl() {
    return $this->imageStyle
      ->toUrl('edit-form');
  }
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'image_effect_delete_form';
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state, ImageStyleInterface $image_style = NULL, $image_effect = NULL) {
    $this->imageStyle = $image_style;
    $this->imageEffect = $this->imageStyle
      ->getEffect($image_effect);
    return parent::buildForm($form, $form_state);
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $this->imageStyle
      ->deleteImageEffect($this->imageEffect);
    $this->messenger()
      ->addStatus($this->t('The image effect %name has been deleted.', [
      '%name' => $this->imageEffect
        ->label(),
    ]));
    $form_state->setRedirectUrl($this->imageStyle
      ->toUrl('edit-form'));
  }

}