jiuyiUniapp/service/node_modules/react-native/Libraries/Utilities/useMergeRefs.js

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2025-02-13 09:59:20 +08:00
/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow strict
* @format
*/
import useRefEffect from './useRefEffect';
import * as React from 'react';
import {useCallback} from 'react';
/**
* Constructs a new ref that forwards new values to each of the given refs. The
* given refs will always be invoked in the order that they are supplied.
*
* WARNING: A known problem of merging refs using this approach is that if any
* of the given refs change, the returned callback ref will also be changed. If
* the returned callback ref is supplied as a `ref` to a React element, this may
* lead to problems with the given refs being invoked more times than desired.
*/
export default function useMergeRefs<Instance>(
...refs: $ReadOnlyArray<?React.RefSetter<Instance>>
): React.RefSetter<Instance> {
const refEffect = useCallback(
(current: Instance) => {
const cleanups: $ReadOnlyArray<void | (() => void)> = refs.map(ref => {
if (ref == null) {
return undefined;
} else {
if (typeof ref === 'function') {
// $FlowIssue[incompatible-type] - Flow does not understand ref cleanup.
const cleanup: void | (() => void) = ref(current);
return typeof cleanup === 'function'
? cleanup
: () => {
ref(null);
};
} else {
ref.current = current;
return () => {
ref.current = null;
};
}
}
});
return () => {
for (const cleanup of cleanups) {
cleanup?.();
}
};
},
[...refs], // eslint-disable-line react-hooks/exhaustive-deps
);
return useRefEffect(refEffect);
}