import * as i0 from "@angular/core";
/**
 * Multiple viewers on one page: the live viewers, in the order they were created.
 *
 * Each <ngx-extended-pdf-viewer> has its own PDFNotificationService and
 * NgxExtendedPdfViewerService. The instances an application injects (root or module
 * level) follow the primary viewer - the oldest live one - so applications with a
 * single viewer work exactly as before.
 *
 * Internal - not part of the public API.
 */
export declare class PdfViewerRegistry {
    private readonly viewers;
    /** the oldest live viewer, or undefined if there's none */
    readonly primary: import("@angular/core").Signal<object>;
    /** the number of live viewers */
    readonly count: import("@angular/core").Signal<number>;
    private readonly lastUsed;
    /** the browser's window.print(), saved before the first viewer replaces it with `print` */
    readonly nativePrint: (() => void) | undefined;
    /**
     * The viewer the user works with: the one clicked or focused last, else the primary viewer.
     * Keyboard shortcuts typed outside every viewer go to this one.
     */
    readonly active: import("@angular/core").Signal<object>;
    /**
     * window.print() while ngx-extended-pdf-viewer prints with pdf.js (`replaceBrowserPrint`): prints the
     * active viewer. One function for all viewers, so it doesn't matter which viewer installed it last.
     */
    readonly print: () => void;
    /** whether a live viewer prints with pdf.js (`replaceBrowserPrint`), so window.print() must stay `print` */
    someViewerPrintsWithPdfJs(): boolean;
    activate(viewer: object): void;
    register(viewer: object): void;
    unregister(viewer: object): void;
    static ɵfac: i0.ɵɵFactoryDeclaration<PdfViewerRegistry, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<PdfViewerRegistry>;
}