import { Injector } from '@angular/core';
export interface InjectIsIntersectingOptions {
    injector?: Injector;
    element?: Element;
}
/**
 * Injects an observable that emits whenever the element is intersecting the viewport.
 * The observable will complete when the element is destroyed.
 * @param options
 *
 * @example
 * export class MyComponent {
 *   private destroyRef = inject(DestroyRef);
 *
 *   isIntersecting$ = injectIsIntersecting();
 *   isInViewport$ = this.isIntersecting$.pipe(
 *     filter(x => x.intersectionRatio > 0),
 *     take(1),
 *   );
 *
 *   ngOnInit() {
 *     this.getData().subscribe();
 *   }
 *
 *   getData() {
 *     // Only fetch data when the element is in the viewport
 *     return this.isInViewport$.pipe(
 *       switchMap(() => this.service.getData()),
 *       takeUntil(this.destroy$)
 *     );
 *   }
 * }
 */
export declare const injectIsIntersecting: ({ injector, element, }?: InjectIsIntersectingOptions) => import("rxjs").Subject<IntersectionObserverEntry>;