All files / src/util FunctionalComponentUtils.tsx

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3x
 
 
3x
 
 
 
 
3x
 
 
 
 
 
 
 
 
 
/*
 * Copyright 2019 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed 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 CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { useEffect, useRef } from 'react';
 
// From https://overreacted.io/making-setinterval-declarative-with-react-hooks/
export function useInterval(callback: Function, delay: number|null) {
  const savedCallback = useRef<Function>();
  
  // Remember the latest callback.
  useEffect(() => {
    savedCallback.current = callback;
  }, [callback]);
  
  // Set up the interval.
  useEffect(() => {
    function tick() {
      (savedCallback.current as Function)();
    }
    if (delay !== null) {
      let id = setInterval(tick, delay);
      return () => clearInterval(id);
    }
  }, [delay]);
}