class ScaleAndCrop

class ScaleAndCrop extends GDImageToolkitOperationBase {
  
  /**
   * {@inheritdoc}
   */
  protected function arguments() {
    return [
      'x' => [
        'description' => 'The horizontal offset for the start of the crop, in pixels',
        'required' => FALSE,
        'default' => NULL,
      ],
      'y' => [
        'description' => 'The vertical offset for the start the crop, in pixels',
        'required' => FALSE,
        'default' => NULL,
      ],
      'width' => [
        'description' => 'The target width, in pixels',
      ],
      'height' => [
        'description' => 'The target height, in pixels',
      ],
    ];
  }
  
  /**
   * {@inheritdoc}
   */
  protected function validateArguments(array $arguments) {
    $actualWidth = $this->getToolkit()
      ->getWidth();
    $actualHeight = $this->getToolkit()
      ->getHeight();
    $scaleFactor = max($arguments['width'] / $actualWidth, $arguments['height'] / $actualHeight);
    $arguments['x'] = isset($arguments['x']) ? (int) round($arguments['x']) : (int) round(($actualWidth * $scaleFactor - $arguments['width']) / 2);
    $arguments['y'] = isset($arguments['y']) ? (int) round($arguments['y']) : (int) round(($actualHeight * $scaleFactor - $arguments['height']) / 2);
    $arguments['resize'] = [
      'width' => (int) round($actualWidth * $scaleFactor),
      'height' => (int) round($actualHeight * $scaleFactor),
    ];
    // Fail when width or height are 0 or negative.
    if ($arguments['width'] <= 0) {
      throw new \InvalidArgumentException("Invalid width ('{$arguments['width']}') specified for the image 'scale_and_crop' operation");
    }
    if ($arguments['height'] <= 0) {
      throw new \InvalidArgumentException("Invalid height ('{$arguments['height']}') specified for the image 'scale_and_crop' operation");
    }
    return $arguments;
  }
  
  /**
   * {@inheritdoc}
   */
  protected function execute(array $arguments = []) {
    return $this->getToolkit()
      ->apply('resize', $arguments['resize']) && $this->getToolkit()
      ->apply('crop', $arguments);
  }

}