import { OnInit, OnDestroy, ElementRef, AfterViewInit, TemplateRef } from '@angular/core';

interface VisibleRange {
    start: number;
    end: number;
}
interface FetchMoreCallback {
    (): Promise<any>;
}

declare class LazyScrollDirective implements OnInit, OnDestroy {
    private el;
    items: any[];
    itemHeight: number;
    viewportHeight: number;
    bufferSize: number;
    fetchMore: FetchMoreCallback;
    visibleRangeChange: any;
    loadingChange: any;
    private engine;
    private scrollListener;
    constructor(el: ElementRef);
    ngOnInit(): void;
    ngOnDestroy(): void;
    private onScroll;
    refresh(): void;
    getVisibleRange(): VisibleRange;
}

declare class LazyScrollComponent implements AfterViewInit, OnDestroy {
    items: any[];
    itemHeight: number;
    viewportHeight: number;
    bufferSize: number;
    fetchMore: () => Promise<any>;
    visibleRangeChange: any;
    loadingChange: any;
    itemTemplate: TemplateRef<any>;
    visibleRange: {
        start: number;
        end: number;
    };
    isLoading: boolean;
    get topPadding(): number;
    get bottomPadding(): number;
    get visibleItems(): any[];
    ngAfterViewInit(): void;
    ngOnDestroy(): void;
    onVisibleRangeChange(range: {
        start: number;
        end: number;
    }): void;
    onLoadingChange(loading: boolean): void;
    trackByFn(index: number, item: any): any;
}

export { LazyScrollComponent, LazyScrollDirective };