@itwin/itwinui-react/esm/utils/hooks/useResizeObserver.js

A react component library for iTwinUI

import * as React from 'react';
import { getWindow } from '../functions/dom.js';
export const useResizeObserver = (onResize) => {
  let resizeObserver = React.useRef(void 0);
  let elementRef = React.useCallback(
    (element) => {
      if (!getWindow()?.ResizeObserver) return;
      resizeObserver.current?.disconnect?.();
      if (element) {
        resizeObserver.current = new ResizeObserver((entries) => {
          window.requestAnimationFrame(() => {
            if (!Array.isArray(entries) || !entries.length) return;
            let [{ contentRect }] = entries;
            return onResize(contentRect);
          });
        });
        resizeObserver.current?.observe?.(element);
      }
    },
    [onResize],
  );
  return [elementRef, resizeObserver.current];
};