interface IconExtractorInterface

interface IconExtractorInterface extends PluginFormInterface {
    
    /**
     * Get a list of all the icons discovered by this extractor.
     *
     * The icons must be provided as an associative array keyed by the icon id
     * with values used to load the icon: source and group.
     *
     * @return array
     *   List of icons that are found by this extractor. Keyed by icon full id.
     */
    public function discoverIcons() : array;
    
    /**
     * Load an icon object.
     *
     * @param array $icon_data
     *   The icon data build in the discoverIcons() method.
     *
     * @return \Drupal\Core\Theme\Icon\IconDefinitionInterface|null
     *   The icon.
     */
    public function loadIcon(array $icon_data) : ?IconDefinitionInterface;
    
    /**
     * Returns the translated plugin label.
     */
    public function label() : string;
    
    /**
     * Returns the translated plugin description.
     */
    public function description() : string;
    
    /**
     * Create the icon definition from an extractor plugin.
     *
     * @param string $icon_id
     *   The id of the icon.
     * @param string|null $source
     *   The source, url or path of the icon.
     * @param string|null $group
     *   The group of the icon.
     * @param array|null $data
     *   The icon data.
     *
     * @return \Drupal\Core\Theme\Icon\IconDefinitionInterface
     *   The icon definition.
     *
     * @see \Drupal\Core\Theme\Icon\IconDefinition::create()
     */
    public function createIcon(string $icon_id, ?string $source = NULL, ?string $group = NULL, ?array $data = NULL) : IconDefinitionInterface;

}