import { Reader } from '../../reader';
import { Observable } from 'rxjs';
export type State = ReturnType<typeof observeState>;
export declare const observeState: (reader: Reader) => Observable<{
    canTurnLeft: boolean;
    canTurnRight: boolean;
    canGoTopSpineItem: boolean;
    canGoBottomSpineItem: boolean;
    canGoLeftSpineItem: boolean;
    canGoRightSpineItem: boolean;
}>;