function ColorizeImageEffect::applyEffect

Overrides ImageEffectInterface::applyEffect

File

modules/image_example/src/Plugin/ImageEffect/ColorizeImageEffect.php, line 26

Class

ColorizeImageEffect

Colorizes an image resource.

Namespace

Code

public function applyEffect(ImageInterface $image) {
    $data = $this->configuration;
    // Verify that Drupal is using the PHP GD library for image manipulations
    // since this effect depends on functions implemented by the GD extension.
    if ($image->getToolkitId() != 'gd') {
        $this->logger
            ->info('Image colorize failed on %file. The image does not use the GD toolkit.', [
            '%file' => $image->getSource(),
        ]);
        return FALSE;
    }
    // phpcs:disable Drupal.Commenting.InlineComment.InvalidEndChar
    // Not all GD installations are created equal. It is a good idea to check
    // for the existence of image manipulation functions before using them.
    // PHP installations using non-bundled GD do not have imagefilter(). See the
    // @link http://www.php.net/manual/en/book.image.php PHP manual @endlink for
    // more information about image manipulation functions.
    // phpcs:enable
    if (!function_exists('imagefilter')) {
        $this->logger
            ->error('The image %image could not be colorized because the imagefilter() function is not available in this PHP installation.', [
            '%file' => $image->getSource(),
        ]);
        return FALSE;
    }
    if (!Color::validateHex($data['color'])) {
        // Use the default value, if the stored value is invalid.
        $data['color'] = '#FF6633';
    }
    $rgb = Color::hexToRgb($data['color']);
    // $source contains the \GdImage instance passed to GD functions.
    // This line only works with the GD toolkit implemented by Drupal core.
    // Other toolkits could not implement getImage(), or that method could
    // return a different value.
    $source = $image->getToolkit()
        ->getImage();
    // First desaturate the image, and then apply the new color.
    imagefilter($source, IMG_FILTER_GRAYSCALE);
    imagefilter($source, IMG_FILTER_COLORIZE, $rgb['red'], $rgb['green'], $rgb['blue']);
    return TRUE;
}