class Image

class Image extends File {
    
    /**
     * Key for "image width" metadata attribute.
     *
     * @var string
     */
    const METADATA_ATTRIBUTE_WIDTH = 'width';
    
    /**
     * Key for "image height" metadata attribute.
     *
     * @var string
     */
    const METADATA_ATTRIBUTE_HEIGHT = 'height';
    
    /**
     * The image factory service.
     *
     * @var \Drupal\Core\Image\ImageFactory
     */
    protected $imageFactory;
    
    /**
     * The file system service.
     *
     * @var \Drupal\Core\File\FileSystemInterface
     */
    protected $fileSystem;
    
    /**
     * Constructs a new class instance.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   Entity type manager service.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
     *   Entity field manager service.
     * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $field_type_manager
     *   The field type plugin manager service.
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   The config factory service.
     * @param \Drupal\Core\Image\ImageFactory $image_factory
     *   The image factory.
     * @param \Drupal\Core\File\FileSystemInterface $file_system
     *   The file system service.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $entity_field_manager, FieldTypePluginManagerInterface $field_type_manager, ConfigFactoryInterface $config_factory, ImageFactory $image_factory, FileSystemInterface $file_system) {
        parent::__construct($configuration, $plugin_id, $plugin_definition, $entity_type_manager, $entity_field_manager, $field_type_manager, $config_factory);
        $this->imageFactory = $image_factory;
        $this->fileSystem = $file_system;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity_type.manager'), $container->get('entity_field.manager'), $container->get('plugin.manager.field.field_type'), $container->get('config.factory'), $container->get('image.factory'), $container->get('file_system'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMetadataAttributes() {
        $attributes = parent::getMetadataAttributes();
        $attributes += [
            static::METADATA_ATTRIBUTE_WIDTH => $this->t('Width'),
            static::METADATA_ATTRIBUTE_HEIGHT => $this->t('Height'),
        ];
        return $attributes;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMetadata(MediaInterface $media, $name) {
        // Get the file and image data.
        
        /** @var \Drupal\file\FileInterface $file */
        $file = $media->get($this->configuration['source_field'])->entity;
        // If the source field is not required, it may be empty.
        if (!$file) {
            return parent::getMetadata($media, $name);
        }
        $uri = $file->getFileUri();
        switch ($name) {
            case static::METADATA_ATTRIBUTE_WIDTH:
                $image = $this->imageFactory
                    ->get($uri);
                return $image->getWidth() ?: NULL;
            case static::METADATA_ATTRIBUTE_HEIGHT:
                $image = $this->imageFactory
                    ->get($uri);
                return $image->getHeight() ?: NULL;
            case 'thumbnail_uri':
                return $uri;
            case 'thumbnail_alt_value':
                return $media->get($this->configuration['source_field'])->alt ?: parent::getMetadata($media, $name);
        }
        return parent::getMetadata($media, $name);
    }
    
    /**
     * {@inheritdoc}
     */
    public function createSourceField(MediaTypeInterface $type) {
        
        /** @var \Drupal\field\FieldConfigInterface $field */
        $field = parent::createSourceField($type);
        // Reset the field to its default settings so that we don't inherit the
        // settings from the parent class' source field.
        $settings = $this->fieldTypeManager
            ->getDefaultFieldSettings($field->getType());
        return $field->set('settings', $settings);
    }
    
    /**
     * {@inheritdoc}
     */
    public function prepareViewDisplay(MediaTypeInterface $type, EntityViewDisplayInterface $display) {
        parent::prepareViewDisplay($type, $display);
        // Use the `large` image style and do not link the image to anything.
        // This will prevent the out-of-the-box configuration from outputting very
        // large raw images. If the `large` image style has been deleted, do not
        // set an image style.
        $field_name = $this->getSourceFieldDefinition($type)
            ->getName();
        $component = $display->getComponent($field_name);
        $component['settings']['image_link'] = '';
        $component['settings']['image_style'] = '';
        if ($this->entityTypeManager
            ->getStorage('image_style')
            ->load('large')) {
            $component['settings']['image_style'] = 'large';
        }
        $display->setComponent($field_name, $component);
    }

}