import { CdkScrollable, ScrollDispatcher } from '@angular/cdk/scrolling';
import { Subscription } from 'rxjs';
/**
 * Define a interface to guarantee a subscription instance to be managed
 * in seupScrollSubscription.
 */
export interface Scrollable {
    /**
     * The subscription for *Scrolldispatcher.scrolled* method call.
     */
    scrolledSubs: Subscription;
}
export declare type Edge = 'top' | 'left' | 'right' | 'bottom' | 'start' | 'end';
/**
 * Setups a new scroll subscription, also unsubscribe from previous subscriptions
 * if needed.
 *
 * @param activate indicates if a new subscription must be created
 * @param componentRef a **scrollable** component that implements `Scrollable` interface
 * @param scrollDispatcher the responsible to listen for scroll events
 * @param windowScrollFn a callback for scroll subscription
 */
export declare const setupScrollSubscription: <C extends Scrollable>(activate: boolean, componentRef: C, scrollDispatcher: ScrollDispatcher, windowScrollFn: Function) => void;
/**
 * A interface to provide information about the last scroll event received.
 */
export interface ScrollInfo {
    /**
     * How many pixels was scrolled.
     */
    offset: number;
    /**
     * Indicates that the scroll was detected.
     */
    scrolled: boolean;
}
export declare const onWindowScroll: (event: CdkScrollable, edge?: "left" | "right" | "start" | "end" | "top" | "bottom", previousScroll?: number, minDif?: number, departureOffset?: number, returnOffset?: number) => ScrollInfo;