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React useAutoScrollToBottom.ts
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| import React from 'react'; | |
| export default function useAutoScrollToBottom(deps) { | |
| const pause = React.useRef(false); | |
| const element = React.useRef<HTMLDivElement | null>(null); | |
| const ref = React.useCallback((el) => { | |
| function onWheel() { | |
| const { scrollTop, scrollHeight, offsetHeight } = element.current || { | |
| scrollTop: 0, | |
| scrollHeight: 0, | |
| offsetHeight: 0, | |
| }; | |
| pause.current = scrollHeight - (scrollTop + offsetHeight) > 4; | |
| } | |
| if (el) { | |
| element.current = el; | |
| el.addEventListener('wheel', onWheel, { passive: true }); | |
| } else if (element.current !== null) { | |
| element.current.removeEventListener('wheel', onWheel); | |
| element.current = null; | |
| } | |
| }, []); | |
| React.useLayoutEffect(() => { | |
| if (element.current && !pause.current) { | |
| element.current.scrollTop = element.current.scrollHeight; | |
| } | |
| }, deps); | |
| return { ref }; | |
| } |
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