import { OnDestroy } from '@angular/core';
import { Subject } from 'rxjs';
import { NavigationItem } from './navigation-item.interface';
import * as i0 from "@angular/core";
export declare class NavigationService implements OnDestroy {
    /** The navigation items to populate the menu with */
    items: NavigationItem[];
    /** Whether to collapse other menu items when expanding a menu item. */
    autoCollapse: boolean;
    /** Emit when the expanded state has changed */
    expanded$: Subject<void>;
    ngOnDestroy(): void;
    /** Set the expanded state of an item */
    setExpanded(source: NavigationItem, expanded: boolean): void;
    /** Collapse all siblings nodes */
    private collapseSiblings;
    /** Collapse an item and all its children */
    private collapseAll;
    /** Get a nodes parent if it has one */
    private getParent;
    static ɵfac: i0.ɵɵFactoryDeclaration<NavigationService, never>;
    static ɵprov: i0.ɵɵInjectableDeclaration<NavigationService>;
}