class Resize

class Resize extends GDImageToolkitOperationBase {
  
  /**
   * {@inheritdoc}
   */
  protected function arguments() {
    return [
      'width' => [
        'description' => 'The new width of the resized image, in pixels',
      ],
      'height' => [
        'description' => 'The new height of the resized image, in pixels',
      ],
    ];
  }
  
  /**
   * {@inheritdoc}
   */
  protected function validateArguments(array $arguments) {
    // Assure integers for all arguments.
    $arguments['width'] = (int) round($arguments['width']);
    $arguments['height'] = (int) round($arguments['height']);
    // Fail when width or height are 0 or negative.
    if ($arguments['width'] <= 0) {
      throw new \InvalidArgumentException("Invalid width ('{$arguments['width']}') specified for the image 'resize' operation");
    }
    if ($arguments['height'] <= 0) {
      throw new \InvalidArgumentException("Invalid height ('{$arguments['height']}') specified for the image 'resize' operation");
    }
    return $arguments;
  }
  
  /**
   * {@inheritdoc}
   */
  protected function execute(array $arguments = []) {
    // Create a new image of the required dimensions, and copy and resize
    // the original image on it with resampling.
    $original_image = $this->getToolkit()
      ->getImage();
    $data = [
      'width' => $arguments['width'],
      'height' => $arguments['height'],
      'extension' => image_type_to_extension($this->getToolkit()
        ->getType(), FALSE),
      'transparent_color' => $this->getToolkit()
        ->getTransparentColor(),
      'is_temp' => TRUE,
    ];
    if ($this->getToolkit()
      ->apply('create_new', $data)) {
      if (imagecopyresampled($this->getToolkit()
        ->getImage(), $original_image, 0, 0, 0, 0, $arguments['width'], $arguments['height'], imagesx($original_image), imagesy($original_image))) {
        return TRUE;
      }
      // In case of failure, restore the original image.
      $this->getToolkit()
        ->setImage($original_image);
    }
    return FALSE;
  }

}