import { WebApp } from '../WebApp';
import { Bridge } from '../Bridge';
import { EventEmitter } from 'twa-core';
import { BackButtonEventsMap } from './events';
declare const ee: EventEmitter<BackButtonEventsMap>;
/**
 * Class which controls the back button, which can be displayed in the header
 * of the Web App in the Telegram interface.
 *
 * TODO: Component requires event which states, button was hidden or shown
 *  from outside.
 *
 * TODO: BackButton works explicitly in case, modal is not expanded. It means,
 *  when you call show(), it looks like nothing happens, but in case, you
 *  expand a Web App modal, back button shows up.
 */
export declare class BackButton {
    private bridge;
    private webApp;
    private ee;
    private _isVisible;
    /**
     * Updates current visibility state.
     *
     * @since Web App version 6.1+
     * @private
     */
    private set isVisible(value);
    constructor(bridge: Bridge, webApp: WebApp);
    /**
     * Hides the button.
     */
    hide: () => void;
    /**
     * Shows whether the button is visible.
     */
    get isVisible(): boolean;
    /**
     * Adds new event listener.
     *
     * @param event - event name.
     * @param listener - event listener.
     */
    on: typeof ee['on'];
    /**
     * Removes event listener.
     *
     * @param event - event name.
     * @param listener - event listener.
     */
    off: typeof ee['off'];
    /**
     * Shows the button.
     */
    show: () => void;
}
export {};