/**
 * The event interface for {@link IEventEmitter}.
 */
export interface IEvent {
    /**
     * Event type.
     */
    type: string;
}
/**
 * Event emitter interface.
 */
export interface IEventEmitter {
    /**
     * Registers a new listener for the event type.
     *
     * @param type - The type of event to listen to.
     * @param listener - The function that gets called when the event is fired.
     */
    addEventListener(type: string, listener: (event: IEvent) => void): this;
    /**
     * Removes the listener for the event type.
     *
     * @param type - The type of the event that gets removed.
     * @param listener - The listener function that gets removed.
     */
    removeEventListener(type: string, listener: (event: IEvent) => void): this;
    /**
     * If `type` is specified, removes all registered listeners for type, otherwise removes all registered
     * listeners.
     *
     * @param type - The type of the listener that gets removed.
     */
    removeAllListeners(type?: string): this;
    /**
     * Fires the event. Calls each of the listeners registered for the event type `event.type`, in the
     * order they were registered.
     *
     * @param event - The event that gets fired.
     */
    emitEvent(event: IEvent): boolean;
    /**
     * Registers a new listener for the event type. Alias to {@link addEventListener | addEventListener()}
     *
     * @param type - The type of event to listen to.
     * @param listener - The function that gets called when the event is fired.
     */
    on(type: string, listener: (event: any) => void): this;
    /**
     * Removes the listener from an event type. Alias to
     * {@link removeEventListener | removeEventListener()}.
     *
     * @param type - The type of the event that gets removed.
     * @param listener - The listener function that gets removed.
     */
    off(type: string, listener: (event: any) => void): this;
    /**
     * Fires the event. Alias to {@link emitEvent | emitEvent()}.
     *
     * @param type - The type of event that gets fired.
     * @param args - The event properties.
     */
    emit(type: string | object, ...args: any[]): boolean;
}
/**
 * The minimal basic event that can be emitted by a {@link EventEmitter2}.
 */
export interface Event<T extends string = string> extends IEvent {
    /**
     * Event type.
     */
    type: T;
}
/**
 * Event emitter for custom objects.
 */
export declare class EventEmitter2<EventMap extends Record<string, any> = Record<string, any>> implements IEventEmitter {
    private _listeners;
    addEventListener<T extends keyof EventMap>(type: T, listener: (event: EventMap[T]) => void): this;
    removeEventListener<T extends keyof EventMap>(type: T, listener: (event: EventMap[T]) => void): this;
    removeAllListeners<T extends keyof EventMap>(type?: T): this;
    emitEvent<T extends keyof EventMap>(event: Event<Extract<T, string>> & EventMap[T]): boolean;
    on(type: string, listener: (event: any) => void): this;
    off(type: string, listener: (event: any) => void): this;
    emit(type: string | object, ...args: any[]): boolean;
}