import { AfterViewInit, ChangeDetectorRef, TemplateRef, OnDestroy } from '@angular/core';
import { DragDispatcher2 } from './drag-dispatcher.service';
import { Observable } from 'rxjs';
export interface PreviewItem {
    id: string;
    template: any;
    context: any;
    show: boolean;
}
export declare class DragLayer implements AfterViewInit, OnDestroy {
    private readonly dragDispatcher;
    private readonly cdRef;
    dragPreviewsEnabled$: Observable<boolean>;
    readonly previewAsArray: PreviewItem[];
    private readonly previews;
    private subscription;
    constructor(dragDispatcher: DragDispatcher2, cdRef: ChangeDetectorRef);
    ngAfterViewInit(): void;
    ngOnDestroy(): void;
    showPreview(id: string, template: TemplateRef<any>, context: any): void;
    hidePreview(id: string): void;
    trackByFn(index: number, item: PreviewItem): string;
    transform(context: any): string;
}