44 lines
1.7 KiB
Plaintext
44 lines
1.7 KiB
Plaintext
import * as React from 'react';
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import { assignRef } from './assignRef';
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import { useCallbackRef } from './useRef';
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const useIsomorphicLayoutEffect = typeof window !== 'undefined' ? React.useLayoutEffect : React.useEffect;
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const currentValues = new WeakMap();
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/**
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* Merges two or more refs together providing a single interface to set their value
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* @param {RefObject|Ref} refs
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* @returns {MutableRefObject} - a new ref, which translates all changes to {refs}
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*
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* @see {@link mergeRefs} a version without buit-in memoization
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* @see https://github.com/theKashey/use-callback-ref#usemergerefs
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* @example
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* const Component = React.forwardRef((props, ref) => {
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* const ownRef = useRef();
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* const domRef = useMergeRefs([ref, ownRef]); // 👈 merge together
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* return <div ref={domRef}>...</div>
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* }
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*/
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export function useMergeRefs(refs, defaultValue) {
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const callbackRef = useCallbackRef(defaultValue || null, (newValue) => refs.forEach((ref) => assignRef(ref, newValue)));
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// handle refs changes - added or removed
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useIsomorphicLayoutEffect(() => {
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const oldValue = currentValues.get(callbackRef);
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if (oldValue) {
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const prevRefs = new Set(oldValue);
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const nextRefs = new Set(refs);
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const current = callbackRef.current;
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prevRefs.forEach((ref) => {
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if (!nextRefs.has(ref)) {
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assignRef(ref, null);
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}
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});
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nextRefs.forEach((ref) => {
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if (!prevRefs.has(ref)) {
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assignRef(ref, current);
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}
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});
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}
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currentValues.set(callbackRef, refs);
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}, [refs]);
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return callbackRef;
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}
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