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

/*
 * Copyright 2020 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, RefObject} from 'react';
import {useLayoutEffect} from './';

interface ContextValue<T> {
  ref?: MutableRefObject<T>
}

// Syncs ref from context with ref passed to hook
export function useSyncRef<T>(context: ContextValue<T>, ref: RefObject<T>) {
  useLayoutEffect(() => {
    if (context && context.ref && ref) {
      context.ref.current = ref.current;
      return () => {
        context.ref.current = null;
      };
    }
  }, [context, ref]);
}