useResizeDetector.tsx

import React, { useEffect, useState, useCallback } from "react";
import { useResizeDetector } from "react-resize-detector";
const AppGamma = () => {
  const [widthA, setWidthA] = useState<number>(800);

  const onResize = useCallback(() => {
    // on resize logic
  }, []);

  const { width, ref } = useResizeDetector({
    onResize,
    refreshMode: "debounce"
  });

  useEffect(() => {
    //do something with the width, remember to use debounce
    console.log(width);
  }, [width]);

  return (
    <>
      <h3> App Gamma </h3>
      <div>
        <button onClick={() => setWidthA(widthA + 100)}> ++ width </button>
        <button onClick={() => setWidthA(widthA - 100)}> -- width </button>
      </div>
      <div className="container-gamma">
        <div className="child-app-A" style={{ width: widthA }}>
          Widget A
        </div>
        <div className="child-app-B" ref={ref}>
          Widget B width: <div>{width} px</div>
        </div>
      </div>
    </>
  );
};

export default AppGamma;