class ScaleImageEffect

class ScaleImageEffect extends ResizeImageEffect {
  
  /**
   * {@inheritdoc}
   */
  public function applyEffect(ImageInterface $image) {
    if (!$image->scale($this->configuration['width'], $this->configuration['height'], $this->configuration['upscale'])) {
      $this->logger
        ->error('Image scale failed using the %toolkit toolkit on %path (%mimetype, %dimensions)', [
        '%toolkit' => $image->getToolkitId(),
        '%path' => $image->getSource(),
        '%mimetype' => $image->getMimeType(),
        '%dimensions' => $image->getWidth() . 'x' . $image->getHeight(),
      ]);
      return FALSE;
    }
    return TRUE;
  }
  
  /**
   * {@inheritdoc}
   */
  public function transformDimensions(array &$dimensions, $uri) {
    if ($dimensions['width'] && $dimensions['height']) {
      Image::scaleDimensions($dimensions, $this->configuration['width'], $this->configuration['height'], $this->configuration['upscale']);
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public function getSummary() {
    $summary = [
      '#theme' => 'image_scale_summary',
      '#data' => $this->configuration,
    ];
    $summary += parent::getSummary();
    return $summary;
  }
  
  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    return parent::defaultConfiguration() + [
      'upscale' => FALSE,
    ];
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
    $form = parent::buildConfigurationForm($form, $form_state);
    $form['width']['#required'] = FALSE;
    $form['height']['#required'] = FALSE;
    $form['upscale'] = [
      '#type' => 'checkbox',
      '#default_value' => $this->configuration['upscale'],
      '#title' => $this->t('Allow Upscaling'),
      '#description' => $this->t('Let scale make images larger than their original size.'),
    ];
    return $form;
  }
  
  /**
   * {@inheritdoc}
   */
  public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
    parent::validateConfigurationForm($form, $form_state);
    if ($form_state->isValueEmpty('width') && $form_state->isValueEmpty('height')) {
      $form_state->setErrorByName('data', $this->t('Width and height can not both be blank.'));
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
    parent::submitConfigurationForm($form, $form_state);
    $this->configuration['upscale'] = $form_state->getValue('upscale');
  }

}