import { OnDestroy, QueryList } from '@angular/core';
import { Observable } from 'rxjs';
import { PageHeaderNavigationItemComponent } from './navigation-item/navigation-item.component';
import * as i0 from "@angular/core";
export declare class PageHeaderNavigationService implements OnDestroy {
    /** Store an instance of the focus key manager */
    private _focusManager;
    /** Store the query list */
    private _items;
    /**
     * Emit when focus changes. We can't directly use the FocusKeyManager
     * `change` observable as it cannot be instantiate until after the view
     * has been instantiated.
     */
    private readonly _onChange;
    /** Unsubscribe on destroy */
    private readonly _onDestroy;
    ngOnDestroy(): void;
    /** Make menu items navigable using arrow keys */
    initialize(items: QueryList<PageHeaderNavigationItemComponent>): void;
    /** Listen for keyboard events */
    onKeydown(event: KeyboardEvent): void;
    /** Get the tab index for this item as an observable */
    getTabIndex(item: PageHeaderNavigationItemComponent): Observable<number>;
    /** Determine the tab index of a given item */
    private getItemTabIndex;
    static ɵfac: i0.ɵɵFactoryDeclaration<PageHeaderNavigationService, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<PageHeaderNavigationService>;
}