import { ComponentRef, ViewRef } from '@angular/core';
import { Observable } from 'rxjs';
export declare const FOCUS = "focus";
export declare enum Key {
    Tab = 9,
    Enter = 13,
    Escape = 27,
    Space = 32,
    PageUp = 33,
    PageDown = 34,
    End = 35,
    Home = 36,
    ArrowLeft = 37,
    ArrowUp = 38,
    ArrowRight = 39,
    ArrowDown = 40
}
export declare const isDefined: (value: any) => boolean;
export declare class ContentRef {
    nodes: any[];
    viewRef?: ViewRef;
    componentRef?: ComponentRef<any>;
    constructor(nodes: any[], viewRef?: ViewRef, componentRef?: ComponentRef<any>);
}
/**
 * Returns first and last focusable elements inside of a given element based on specific CSS selector
 */
export declare const getFocusableBoundaryElements: (element: HTMLElement) => HTMLElement[];
/**
 * Function that enforces browser focus to be trapped inside a DOM element.
 *
 * Works only for clicks inside the element and navigation with 'Tab', ignoring clicks outside of the element
 *
 * @param element The element around which focus will be trapped inside
 * @param stopFocusTrap$ The observable stream. When completed the focus trap will clean up listeners
 * and free internal resources
 * @param refocusOnClick Put the focus back to the last focused element whenever a click occurs on element (default to
 * false)
 */
export declare const focusTrap: (element: HTMLElement, stopFocusTrap$: Observable<any>, refocusOnClick?: boolean) => void;