react-test/docs/data/material/components/popper/SpringPopper.tsx

import * as React from 'react';
import Box from '@mui/material/Box';
import Popper from '@mui/material/Popper';
import { useSpring, animated } from '@react-spring/web';

interface FadeProps {
  children?: React.ReactElement<unknown>;
  in?: boolean;
  onEnter?: () => void;
  onExited?: () => void;
}

const Fade = React.forwardRef<HTMLDivElement, FadeProps>(function Fade(props, ref) {
  const { in: open, children, onEnter, onExited, ...other } = props;
  const style = useSpring({
    from: { opacity: 0 },
    to: { opacity: open ? 1 : 0 },
    onStart: () => {
      if (open && onEnter) {
        onEnter();
      }
    },
    onRest: () => {
      if (!open && onExited) {
        onExited();
      }
    },
  });

  return (
    <animated.div ref={ref} style={style} {...other}>
      {children}
    </animated.div>
  );
});

export default function SpringPopper() {
  const [open, setOpen] = React.useState(false);
  const [anchorEl, setAnchorEl] = React.useState<null | HTMLElement>(null);

  const handleClick = (event: React.MouseEvent<HTMLElement>) => {
    setAnchorEl(event.currentTarget);
    setOpen((previousOpen) => !previousOpen);
  };

  const canBeOpen = open && Boolean(anchorEl);
  const id = canBeOpen ? 'spring-popper' : undefined;

  return (
    <div>
      <button aria-describedby={id} type="button" onClick={handleClick}>
        Toggle Popper
      </button>
      <Popper id={id} open={open} anchorEl={anchorEl} transition>
        {({ TransitionProps }) => (
          <Fade {...TransitionProps}>
            <Box sx={{ border: 1, p: 1, bgcolor: 'background.paper' }}>
              The content of the Popper.
            </Box>
          </Fade>
        )}
      </Popper>
    </div>
  );
}