import { SingleSubject } from '../types/signal';
import { BalElementStateInfo, BalElementStateObserver } from './element-states.interfaces';
export declare class BalElementStateSubject extends SingleSubject<BalElementStateObserver, BalElementStateInfo> {
    private listener;
    constructor();
    attach(observer: BalElementStateObserver): void;
    detach(): void;
}
