import { AfterViewInit, OnChanges, OnDestroy } from "@angular/core";
/**
 * Puts the host into the tab sequence as a labelled region while its content overflows,
 * so it can be scrolled by keyboard even without focusable descendants (WCAG 2.1.1, ACT rule 0ssw9k).
 */
export declare class FocusableScrollRegionDirective implements AfterViewInit, OnChanges, OnDestroy {
    /** Space-separated ids of the elements labelling the region */
    labelledBy: string;
    private readonly elementRef;
    private readonly renderer;
    private readonly zone;
    private resizeObserver?;
    ngAfterViewInit(): void;
    ngOnChanges(): void;
    ngOnDestroy(): void;
    private update;
}