@lancecummings/use-scroll-position v1.1.45

use-scroll-position

use-scroll-position is a React hook that returns the browser viewport X and Y scroll position. It is highly optimized and using the special technics to avoid unnecessary rerenders!

It uses the default react hooks rendering lifecycle, which allows you to fully control its behavior and prevent unnecessary renders.

Demo

• Hide navbar on scroll
• Hide/Show sidebar on scroll
• Display viewport scroll position

Install

yarn add @n8tb1t/use-scroll-position

Usage

useScrollPosition(effect,deps, element, useWindow, wait)

The useScrollPosition returns prevPos and currPos.

Examples

Log current scroll position

import { useScrollPosition } from '@n8tb1t/use-scroll-position'
  
useScrollPosition(({ prevPos, currPos }) => {
  console.log(currPos.x)
  console.log(currPos.y)
})

Change state based on scroll position - Inline CSS

import React, { useState } from 'react'
import { useScrollPosition } from '@n8tb1t/use-scroll-position'

const [headerStyle, setHeaderStyle] = useState({
  transition: 'all 200ms ease-in'
})

useScrollPosition(
  ({ prevPos, currPos }) => {
    const isVisible = currPos.y > prevPos.y

    const shouldBeStyle = {
      visibility: isVisible ? 'visible' : 'hidden',
      transition: `all 200ms ${isVisible ? 'ease-in' : 'ease-out'}`,
      transform: isVisible ? 'none' : 'translate(0, -100%)'
    }

    if (JSON.stringify(shouldBeStyle) === JSON.stringify(headerStyle)) return

    setHeaderStyle(shouldBeStyle)
  },
  [headerStyle]
)

const Header = <header style={{ ...headerStyle }} />

Change state based on scroll position - Styled Components

import React, { useState } from 'react'
import { useScrollPosition } from '@n8tb1t/use-scroll-position'

const [hideOnScroll, setHideOnScroll] = useState(true)
  
useScrollPosition(({ prevPos, currPos }) => {
  const isShow = currPos.y > prevPos.y
  if (isShow !== hideOnScroll) setHideOnScroll(isShow)
}, [hideOnScroll])

Get scroll position for custom element

  const [elementPosition, setElementPosition] = useState({ x: 20, y: 150 })
  const elementRef = useRef()
  
    // Element scroll position
  useScrollPosition(
    ({ currPos }) => {
      setElementPosition(currPos)
    }, [], elementRef
  )

Why to use

use-scroll-position returns the scroll position of the browser window, using a modern, stable and performant implementation.

Most of the time scroll listeners do very expensive work, such as querying dom elements, reading height / width and so on. use-scroll-position solves this by using throttling technic to avoid too many reflows (the browser to recalculate everything).