react-use/src/useSpring.ts

/* eslint-disable */
import { useEffect, useMemo, useState } from 'react';
import { Spring, SpringSystem } from 'rebound';

const useSpring = (targetValue: number = 0, tension: number = 50, friction: number = 3) => {
  const [spring, setSpring] = useState<Spring | null>(null);
  const [value, setValue] = useState<number>(targetValue);

  // memoize listener to being able to unsubscribe later properly, otherwise
  // listener fn will be different on each re-render and wouldn't unsubscribe properly.
  const listener = useMemo(
    () => ({
      onSpringUpdate: currentSpring => {
        const newValue = currentSpring.getCurrentValue();
        setValue(newValue);
      },
    }),
    []
  );

  useEffect(() => {
    if (!spring) {
      const newSpring = new SpringSystem().createSpring(tension, friction);
      newSpring.setCurrentValue(targetValue);
      setSpring(newSpring);
      newSpring.addListener(listener);
    }

    return () => {
      if (spring) {
        spring.removeListener(listener);
        setSpring(null);
      }
    };
  }, [tension, friction, spring]);

  useEffect(() => {
    if (spring) {
      spring.setEndValue(targetValue);
    }
  }, [targetValue]);

  return value;
};

export default useSpring;