import { type IEvent } from './event.js';
import type { DisposeFunction, IDisposable } from '../functions/disposer.js';
import { Getter } from '../types/getter.js';
import type { Nullable } from '../types/misc.js';
import { Loggable } from '../logger/loggable.js';
export type TransitionReaction<T> = (getter: Getter<T>, handler: (v: T) => any) => DisposeFunction;
export declare class TransitionObserver<T> extends Loggable implements IDisposable {
    protected readonly reaction: TransitionReaction<T>;
    private _event;
    private _getter;
    private _filter;
    private _disposer;
    private _prev;
    private _from;
    private _to;
    private _cb;
    private _fireOnce;
    private _promise;
    private _promiseReject;
    constructor(reaction: TransitionReaction<T>, getter?: () => T);
    get event(): IEvent<T>;
    get currentValue(): Nullable<T>;
    get isObserving(): boolean;
    private get isPromising();
    observe(getter: () => T): this;
    from(from: Getter<T>): this;
    to(to: Getter<T>): this;
    filter(filter: (next: T, prev: Nullable<T>) => boolean): this;
    cb(cb: (v: Nullable<T>) => any): this;
    forceCall(): this;
    fireOnce(enable?: boolean): this;
    forceCheck(): boolean;
    andForceCheck(): this;
    getPromise(timeout?: number | null): Promise<Nullable<T>>;
    reverse(): TransitionObserver<T>;
    dispose: () => void;
    private _checkValue;
    private _finishPromise;
}
export declare function waitFor<T>(reaction: TransitionReaction<T>, current: () => T, toBe: T): Promise<Nullable<T>>;