import { QueryList } from '@angular/core';
import { ScrollSpyItemDirective } from '../scroll-spy-item/scroll-spy-item.directive';
import { Spy } from '../shared/spy.model';
/**
 * Service that stores a list of `Spy`'s and the state
 * of their nav items `inViewport` and `active` state
 *
 */
export declare class ScrollSpyService {
    /**
     * List of `Spy`'s
     *
     * @memberof ScrollSpyService
     */
    spys: Spy[];
    /**
     * Stores requests to add items to spy when spy hasn't been created
     * yet. Once spy has been added then request will be made again.
     *
     * @memberof ScrollSpyService
     */
    buffer: any[];
    /**
     * Add spy to list of `spys`
     *
     * @memberof ScrollSpyService
     */
    addSpy(id: string, items: QueryList<ScrollSpyItemDirective>): void;
    /**
     * Remove spy from list of `spys`
     *
     * @memberof ScrollSpyService
     */
    removeSpy(id: string): void;
    /**
     * Set the `inViewport` status for a spy item then sets the active
     * to true for the first item in the list that has `inViewport`
     * set to true
     *
     * @memberof ScrollSpyService
     */
    setSpySectionStatus(sectionId: string, spyId: string, inViewport: boolean): void;
}