68 lines
2.1 KiB
TypeScript
68 lines
2.1 KiB
TypeScript
/*
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Copyright 2020 The Matrix.org Foundation C.I.C.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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import {useEffect, useRef, useState} from "react";
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type Handler = () => void;
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// Hook to simplify timeouts in functional components
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export const useTimeout = (handler: Handler, timeoutMs: number) => {
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// Create a ref that stores handler
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const savedHandler = useRef<Handler>();
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// Update ref.current value if handler changes.
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useEffect(() => {
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savedHandler.current = handler;
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}, [handler]);
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// Set up timer
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useEffect(() => {
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const timeoutID = setTimeout(() => {
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savedHandler.current();
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}, timeoutMs);
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return () => clearTimeout(timeoutID);
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}, [timeoutMs]);
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};
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// Hook to simplify intervals in functional components
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export const useInterval = (handler: Handler, intervalMs: number) => {
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// Create a ref that stores handler
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const savedHandler = useRef<Handler>();
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// Update ref.current value if handler changes.
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useEffect(() => {
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savedHandler.current = handler;
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}, [handler]);
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// Set up timer
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useEffect(() => {
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const intervalID = setInterval(() => {
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savedHandler.current();
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}, intervalMs);
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return () => clearInterval(intervalID);
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}, [intervalMs]);
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};
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// Hook to simplify a variable counting down to 0, handler called when it reached 0
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export const useExpiringCounter = (handler: Handler, intervalMs: number, initialCount: number) => {
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const [count, setCount] = useState(initialCount);
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useInterval(() => setCount(c => c - 1), intervalMs);
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if (count === 0) {
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handler();
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}
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return count;
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};
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