import { BehaviorSubjectable } from '../abstract/behavior.subjectable';
export declare const enum ScrollDirections {
    none = 0,
    up = 1,
    down = 2
}
export declare const enum ScrollSpeeds {
    slow = 1,
    regular = 2,
    fast = 3
}
export declare type ScrollDirection = ScrollDirections.up | ScrollDirections.down | ScrollDirections.none;
export declare type ScrollSpeed = ScrollSpeeds.regular | ScrollSpeeds.fast;
export interface IScrollInformation {
    direction: ScrollDirection;
    speed: ScrollSpeed;
}
/**
 * ScrollDirection
 * ===============
 *
 * ## Usage
 *
 * ```typescript
 * import {
 *   ScrollDirectionSubject
 * } from '@mralexandernickel/frontend-subjects/dist/scroll.direction/scroll.direction';
 *
 * export default new ScrollDirectionSubject();
 * ```
 *
 * ```typescript
 * import ScrollDirection from './ScrollDirection';
 * ScrollDirection.get().subscribe(scrollDirection => {
 *   console.log('Direction is now:', scrollDirection);
 * });
 * ```
 */
export declare class ScrollDirectionSubject extends BehaviorSubjectable {
    /**
     * SetTimeout handle
     */
    private timer;
    /**
     * Initial scroll information
     */
    private scrollInformation;
    /**
     * Last saved offset of window
     */
    private lastScrollTop;
    /**
     * @constructor
     */
    constructor();
    /**
     * Detect if the user has stopped scrolling
     */
    private detectStop;
    /**
     * Detect in which direction the user is scrolling
     * @param scrollTop current scrollTop
     */
    private detectDirection;
    /**
     * Detect how fast the user is scrolling
     * @param scrollTop current scrollTop
     */
    private detectSpeed;
    /**
     * Find out if the body been scrolled to top
     * @param scrollTop current scrollTop position
     */
    static scrolledToTop(scrollTop: number): boolean;
    /**
     * Find out if the body been scrolled to bottom
     * @param scrollTop current scrollTop position
     */
    static scrolledToBottom(scrollTop: number): boolean;
    /**
     * Check if one boundary is reached
     * @param scrollTop current scrollTop position
     */
    static boundaryReached(scrollTop: number): boolean;
    /**
     * Reset scroll information
     */
    private reset;
    /**
     * Callback function for the onscroll event-listener
     * @return {void}
     */
    private scrollHandler;
}