import { ElementRef, EventEmitter, OnDestroy, OnInit } from '@angular/core';
import { RcInviewService } from '../../../rc-utils/rc-inview/rc-inview.service';
/**
 * Rc inview directive - emit a callback function with true / false each time the element enter or out the screen
 * Support a margin value - in order to prevent the content to be seen loaded
 *
 * @example
 * <div lib-rc-inview [rcInviewMargin]="200" (rcInviewCallback)="inview($event)">some content</div>
 */
export declare class RcInviewDirective implements OnInit, OnDestroy {
    private elem;
    private rcInviewService;
    /**
     * element margin to trigger the callback
     */
    rcInviewMargin: number;
    /**
     * a callback function trigger once the element enter or our the screen
     */
    rcInviewCallback: EventEmitter<any>;
    private inside;
    private scrollSubscriber;
    constructor(elem: ElementRef, rcInviewService: RcInviewService);
    /**
     * subscribe to scrolling event and calculate init state of element
     */
    ngOnInit(): void;
    /**
     * calculate if the element got out or into the screen and emit a callback accordingly
     */
    isInViewport(): void;
    /**
     * unsubscribe from event
     */
    ngOnDestroy(): void;
}