import { ReactNode } from 'react';
import { Observable } from 'rxjs';
/**
 * unwrap an observable value, return it to the component for rendering, and
 * trigger re-render when value changes
 *
 * **IMPORTANT**. Parent and child components better not subscribe to the same
 * observable, otherwise unnecessary re-render would be triggered. Instead, the
 * top-most component should subscribe and pass value of the observable to
 * its offspring, by props or context. Please consider using `useDependencyContext` and
 * `useDependencyContextValue` in this case.
 *
 * @deprecated Please use `useObservable` instead.
 */
export declare function useDependencyValue<T>(depValue$: Observable<T>, defaultValue?: T): T | undefined;
type ObservableOrFn<T> = Observable<T> | (() => Observable<T>);
type Nullable<T> = T | undefined | null;
export declare function useObservable<T>(observable: Nullable<ObservableOrFn<T>>): T | undefined;
export declare function useObservable<T>(observable: Nullable<ObservableOrFn<T>>, defaultValue: T): T;
export declare function useObservable<T>(observable: Nullable<ObservableOrFn<T>>, defaultValue: undefined, shouldHaveSyncValue: true, deps?: any[]): T;
export declare function useObservable<T>(observable: Nullable<ObservableOrFn<T>>, defaultValue?: undefined, shouldHaveSyncValue?: true, deps?: any[]): T | undefined;
/**
 * subscribe to a signal that emits whenever data updates and re-render
 *
 * @param update$ a signal that the data the functional component depends has updated
 */
export declare function useUpdateBinder(update$: Observable<void>): void;
/**
 * subscribe to an observable value from a service, creating a context for it so
 * it child component won't have to subscribe again and cause unnecessary
 */
export declare function useDependencyContext<T>(depValue$: Observable<T>, defaultValue?: T): {
    Provider: (props: {
        initialState?: T;
        children: ReactNode;
    }) => JSX.Element;
    value: T | undefined;
};
export declare function useDependencyContextValue<T>(depValue$: Observable<T>): T | undefined;
export {};