class MediaSource

class MediaSource extends Plugin {
    
    /**
     * The plugin ID.
     *
     * @var string
     */
    public $id;
    
    /**
     * The human-readable name of the media source.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $label;
    
    /**
     * A brief description of the media source.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $description = '';
    
    /**
     * The field types that can be used as a source field for this media source.
     *
     * @var string[]
     */
    public $allowed_field_types = [];
    
    /**
     * The classes used to define media source-specific forms.
     *
     * An array of form class names, keyed by ID. The ID represents the operation
     * the form is used for.
     *
     * @var string[]
     */
    public $forms = [];
    
    /**
     * A filename for the default thumbnail.
     *
     * The thumbnails are placed in the directory defined by the config setting
     * 'media.settings.icon_base_uri'. When using custom icons, make sure the
     * module provides a hook_install() implementation to copy the custom icons
     * to this directory. The media_install() function provides a clear example
     * of how to do this.
     *
     * @var string
     *
     * @see media_install()
     */
    public $default_thumbnail_filename = 'generic.png';
    
    /**
     * The metadata attribute name to provide the thumbnail URI.
     *
     * @var string
     */
    public $thumbnail_uri_metadata_attribute = 'thumbnail_uri';
    
    /**
     * The metadata attribute name to provide the thumbnail width.
     *
     * @var string
     */
    public $thumbnail_width_metadata_attribute = 'thumbnail_width';
    
    /**
     * The metadata attribute name to provide the thumbnail height.
     *
     * @var string
     */
    public $thumbnail_height_metadata_attribute = 'thumbnail_height';
    
    /**
     * (optional) The metadata attribute name to provide the thumbnail alt.
     *
     * "Thumbnail" will be used if the attribute name is not provided.
     *
     * @var string|null
     */
    public $thumbnail_alt_metadata_attribute;
    
    /**
     * (optional) The metadata attribute name to provide the thumbnail title.
     *
     * The name of the media item will be used if the attribute name is not
     * provided.
     *
     * @var string|null
     */
    public $thumbnail_title_metadata_attribute;
    
    /**
     * The metadata attribute name to provide the default name.
     *
     * @var string
     */
    public $default_name_metadata_attribute = 'default_name';

}