import { IEventBus } from "../Models/IImageViewer";
export declare type EventBusAttachOptions = {
    external?: boolean;
    once?: boolean;
};
export declare type EventBusEventName = "before-open" | "after-open" | "before-close" | "after-close" | "zoom-changed" | "frame-index-changed" | "animation-started" | "animation-stopped" | "keydown" | "keyup";
export declare class EventBus implements IEventBus {
    private _listeners;
    constructor();
    on(eventName: EventBusEventName, listener: any, options?: EventBusAttachOptions): void;
    off(eventName: EventBusEventName, listener: any): void;
    offAll(eventName: EventBusEventName): void;
    dispatch(eventName: EventBusEventName, data: any): void;
    _on(eventName: EventBusEventName, listener: any, options?: EventBusAttachOptions): void;
    _off(eventName: EventBusEventName, listener: Function | false): void;
}