import { ApplicationRef, ComponentFactoryResolver, Injector } from '@angular/core';
export interface OverlayOptions {
    opacity: number;
    zIndex?: number;
    onClick?: () => void;
    getContainer?: () => HTMLElement;
}
/** @dynamic */
export declare class OverlayHelper {
    private appRef;
    private cfr;
    private injector;
    private document;
    constructor(appRef: ApplicationRef, cfr: ComponentFactoryResolver, injector: Injector, document: Document);
    open(options: OverlayOptions): () => void;
    private getDefaultOptions;
    private setListener;
}