import { ViewportRuler } from '@angular/cdk/overlay';
import * as i0 from "@angular/core";
export declare class NgDocScrollService {
    private readonly document;
    private readonly viewportRuler;
    private readonly scrollStrategy;
    constructor(document: Document, viewportRuler: ViewportRuler);
    /**
     * Block global scroll
     */
    block(): void;
    /**
     * Unblock global scroll
     */
    unblock(): void;
    static ɵfac: i0.ɵɵFactoryDeclaration<NgDocScrollService, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<NgDocScrollService>;
}