status-web/packages/components/hooks/use-blur.ts

69 lines
1.6 KiB
TypeScript

import { useEffect, useState } from 'react'
import { useThrottle } from './use-throttle'
interface UseBlurReturn {
shouldBlurBottom: boolean
shouldBlurTop: boolean
}
type UseBlurProps = {
ref: React.RefObject<HTMLDivElement>
marginBlurBottom?: number
heightTop?: number
throttle?: number
}
const useBlur = (props: UseBlurProps): UseBlurReturn => {
const {
marginBlurBottom = 32,
heightTop = 56,
throttle = 100,
ref,
} = props || {}
const [shouldBlurTop, setShouldBlurTop] = useState(false)
const [shouldBlurBottom, setShouldBlurBottom] = useState(false)
const handleScroll = useThrottle(() => {
const scrollPosition = ref.current!.scrollTop
const elementHeight = ref.current!.clientHeight
const scrollHeight = ref.current?.scrollHeight || 0
if (scrollPosition >= heightTop) {
setShouldBlurTop(true)
}
if (scrollPosition < heightTop) {
setShouldBlurTop(false)
}
if (scrollPosition < scrollHeight - (elementHeight + marginBlurBottom)) {
setShouldBlurBottom(true)
}
if (scrollPosition >= scrollHeight - (elementHeight + marginBlurBottom)) {
setShouldBlurBottom(false)
}
}, throttle)
useEffect(() => {
const element = props.ref
if (!element.current) {
throw new Error('useBlur ref not set correctly')
}
element.current!.addEventListener('scroll', handleScroll, { passive: true })
handleScroll()
return () => {
element.current!.removeEventListener('scroll', handleScroll)
}
}, [handleScroll, props.ref])
return { shouldBlurBottom, shouldBlurTop }
}
export { useBlur }