import { MutableRefObject } from 'react';
export declare function randomID(prefix?: string, len?: number, pattern?: string): string;
export declare const getPortalContainer: (id: string, zIndex?: number) => HTMLElement;
/**
 * Z-index maping
 */
export declare const Layers: {
    default: number;
    Modal: number;
    Alerts: number;
    Toast: number;
    Select: number;
    Drawer: number;
    OverlaySurfaces: number;
};
export declare const sleep: (ms: number, clear?: MutableRefObject<(() => void) | null>) => Promise<"completed" | "canceled">;
export declare const modalCanEscape: (portalRoot: HTMLElement, backDropRef: any) => boolean;
export declare function rem2px(rem: number): number;
export declare function px2rem(pixels: number): number;
export declare function isBackdropClick(target: HTMLElement): boolean;