@react-aria/utils/src/useObjectRef.ts

Spectrum UI components in React

/*
 * Copyright 2021 Adobe. All rights reserved.
 * This file is licensed to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under
 * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

import {MutableRefObject, useMemo, useRef} from 'react';

/**
 * Offers an object ref for a given callback ref or an object ref. Especially
 * helfpul when passing forwarded refs (created using `React.forwardRef`) to
 * React Aria Hooks.
 *
 * @param forwardedRef The original ref intended to be used.
 * @returns An object ref that updates the given ref.
 * @see https://reactjs.org/docs/forwarding-refs.html
 */
export function useObjectRef<T>(forwardedRef?: ((instance: T | null) => void) | MutableRefObject<T | null> | null): MutableRefObject<T> {
  const objRef = useRef<T>();
  return useMemo(() => ({
    get current() {
      return objRef.current;
    },
    set current(value) {
      objRef.current = value;
      if (typeof forwardedRef === 'function') {
        forwardedRef(value);
      } else if (forwardedRef) {
        forwardedRef.current = value;
      }
    }
  }), [forwardedRef]);
}