import { useState, useEffect } from 'react'
import Link from 'next/link'
import ThemePicker from 'shared/components/theme-picker.js'
import LocalePicker from 'shared/components/locale-picker.js'
import PatternPicker from 'site/components/pattern-picker.js'
import VersionPicker from 'site/components/version-picker.js'
import CloseIcon from 'shared/components/icons/close.js'
import MenuIcon from 'shared/components/icons/menu.js'
const Right = props => (
)
const Left = props => (
)
const Header = ({ app }) => {
const [prevScrollPos, setPrevScrollPos] = useState(0)
const [show, setShow] = useState(true)
useEffect(() => {
if (typeof window !== 'undefined') {
const handleScroll = () => {
const curScrollPos = (typeof window !== 'undefined') ? window.pageYOffset : 0
if (curScrollPos >= prevScrollPos) {
if (show && curScrollPos > 20) setShow(false)
}
else setShow(true)
setPrevScrollPos(curScrollPos)
}
window.addEventListener('scroll', handleScroll)
return () => window.removeEventListener('scroll', handleScroll)
}
}, [prevScrollPos, show])
return (
)
}
export default Header