Proyectos de Subversion LeadersLinked - SPA

import { useState, useEffect, useRef } from 'react'

export function useNearScreen({

  externalRef,

  once = true,

  rootMargin = '100px'

}) {

  const [isNearScreen, setShow] = useState(false)

  const fromRef = useRef(null)

  useEffect(() => {

    const element = externalRef ? externalRef.current : fromRef.current

    const onChange = (entries, observer) => {

      const el = entries[0]

      if (el.isIntersecting) {

        setShow(true)

        once && observer.disconnect()

      } else {

        !once && setShow(false)

      }

    }

    const observer = new IntersectionObserver(onChange, {

      rootMargin

    })

    if (element) observer.observe(element)

    return () => observer && observer.disconnect()

  }, [externalRef, fromRef])

  return [isNearScreen, fromRef]

}