36 lines
1.3 KiB
TypeScript
36 lines
1.3 KiB
TypeScript
// Copyright 2021 Signal Messenger, LLC
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// SPDX-License-Identifier: AGPL-3.0-only
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import type { MutableRefObject, Ref } from 'react';
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import memoizee from 'memoizee';
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/**
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* Merges multiple refs.
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*
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* Returns a new function each time, which may cause unnecessary re-renders. Try
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* `createRefMerger` if you want to cache the function.
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*/
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export function refMerger<T>(
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...refs: Array<Ref<unknown>>
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): (topLevelRef: T) => void {
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return (el: T) => {
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refs.forEach(ref => {
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// This is a simplified version of [what React does][0] to set a ref.
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// [0]: https://github.com/facebook/react/blob/29b7b775f2ecf878eaf605be959d959030598b07/packages/react-reconciler/src/ReactFiberCommitWork.js#L661-L677
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if (typeof ref === 'function') {
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ref(el);
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} else if (ref) {
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// I believe the types for `ref` are wrong in this case, as `ref.current` should
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// not be `readonly`. That's why we do this cast. See [the React source][1].
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// [1]: https://github.com/facebook/react/blob/29b7b775f2ecf878eaf605be959d959030598b07/packages/shared/ReactTypes.js#L78-L80
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// eslint-disable-next-line no-param-reassign
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(ref as MutableRefObject<T>).current = el;
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}
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});
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};
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}
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export function createRefMerger(): typeof refMerger {
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return memoizee(refMerger, { length: false, max: 1 });
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}
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