File: /var/www/html/tmpr/../tmpr/../tmpr/..//tmpr/../node_modules/@react-aria/utils/src/useValueEffect.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 {Dispatch, useCallback, useRef, useState} from 'react';
import {useLayoutEffect} from './';
type SetValueAction<S> = (prev: S) => Generator<any, void, unknown>;
// This hook works like `useState`, but when setting the value, you pass a generator function
// that can yield multiple values. Each yielded value updates the state and waits for the next
// layout effect, then continues the generator. This allows sequential updates to state to be
// written linearly.
export function useValueEffect<S>(defaultValue: S | (() => S)): [S, Dispatch<SetValueAction<S>>] {
let [value, setValue] = useState(defaultValue);
let valueRef = useRef(value);
let effect = useRef(null);
valueRef.current = value;
// Store the function in a ref so we can always access the current version
// which has the proper `value` in scope.
let nextRef = useRef(null);
nextRef.current = () => {
// Run the generator to the next yield.
let newValue = effect.current.next();
// If the generator is done, reset the effect.
if (newValue.done) {
effect.current = null;
return;
}
// If the value is the same as the current value,
// then continue to the next yield. Otherwise,
// set the value in state and wait for the next layout effect.
if (value === newValue.value) {
nextRef.current();
} else {
setValue(newValue.value);
}
};
useLayoutEffect(() => {
// If there is an effect currently running, continue to the next yield.
if (effect.current) {
nextRef.current();
}
});
let queue = useCallback(fn => {
effect.current = fn(valueRef.current);
nextRef.current();
}, [effect, nextRef]);
return [value, queue];
}