import { PdfDict, PdfStream, PdfValue } from '../pdf/objects.js';
import { PdfFile } from './document.js';
/**
 * The optional-content groups the file's DEFAULT configuration turns off
 * (§8.11.4.3).
 *
 * `/BaseState` says what an unlisted group does — `/ON` unless the file says
 * `/OFF` — and the `/ON` and `/OFF` arrays name the exceptions, `/OFF` last.
 *
 * @param file The document.
 * @returns The resolved OCG dictionaries that are hidden.
 */
export declare function hiddenGroups(file: PdfFile): ReadonlySet<PdfValue>;
/**
 * Whether an `/OC` entry names something the page does not show.
 *
 * The entry is either a group itself or an `/OCMD` — a membership dictionary
 * naming several groups and a `/P` policy over them (§8.11.2.3). `AnyOn` is the
 * default and the common case: the content shows if any of its groups does.
 *
 * @param file The document.
 * @param oc   The `/OC` value, unresolved.
 * @returns `true` where the content it guards is hidden.
 */
export declare function hiddenByOc(file: PdfFile, oc: PdfValue | undefined): boolean;
/**
 * The `/Properties` names a page's content may name in `/OC … BDC` that are
 * hidden (§8.11.3.2).
 *
 * @param file      The document.
 * @param resources The resource dictionary in force.
 * @returns Name → hidden, for the names that ARE hidden.
 */
export declare function hiddenProperties(file: PdfFile, resources: PdfDict | undefined): Set<string>;
/** Whether an XObject carries an `/OC` that hides it (§8.11.3.1). */
export declare function hiddenXObject(file: PdfFile, stream: PdfStream): boolean;