import * as React from "react" ; example internal export function useEventListener ( eventName , handler , element ) { const savedHandler = React . useRef < ( event : Event ) => void > ( ) ; React . useEffect ( ( ) => { savedHandler . current = handler ; } , [ handler ] ) ; React . useEffect ( ( ) => { if ( ! element ) { return ; } const eventListener = ( event ) => { if ( savedHandler . current ) savedHandler . current ( event ) ; } ; element . addEventListener ( eventName , eventListener ) ; return ( ) => { element . removeEventListener ( eventName , eventListener ) ; } ; } , [ eventName , element ] ) ; }