import React , { createContext , useCallback , useEffect , useRef , useState , } from 'react' ; const GamepadsContext = createContext ( { } ) ; interface GamepadsProviderProps { children : React . ReactNode ; } const GamepadsProvider = ( { children } ) => { const [ gamepads , setGamepads ] = useState ( { } ) ; const requestRef = useRef < number > ( ) ; var haveEvents = 'ongamepadconnected' in window ; const addGamepad = useCallback ( gamepad => { setGamepads ( { ... gamepads , [ gamepad . index ] : { buttons : gamepad . buttons , id : gamepad . id , axes : gamepad . axes } } ) ; } , [ gamepads , setGamepads ] ) ; param { object } e const connectGamepadHandler = ( e ) => { addGamepad ( ( e as GamepadEvent ) . gamepad ) ; } ; /**
     * Finds all gamepads and adds them to context
     */ const scanGamepads = useCallback ( ( ) => { var detectedGamepads = navigator . getGamepads ? navigator . getGamepads ( ) : navigator . webkitGetGamepads ? navigator . webkitGetGamepads ( ) : [ ] ; for ( var i = 0 ; i < detectedGamepads . length ; i ++ ) { if ( detectedGamepads [ i ] ) { addGamepad ( detectedGamepads [ i ] ) ; } } } , [ addGamepad ] ) ; useEffect ( ( ) => { window . addEventListener ( 'gamepadconnected' , connectGamepadHandler ) ; return window . removeEventListener ( 'gamepadconnected' , connectGamepadHandler ) ; } ) ; const animate = useCallback ( ( ) => { if ( ! haveEvents ) scanGamepads ( ) ; requestRef . current = requestAnimationFrame ( animate ) ; } , [ requestRef , scanGamepads , haveEvents ] ) ; useEffect ( ( ) => { requestRef . current = requestAnimationFrame ( animate ) ; return ( ) => cancelAnimationFrame ( requestRef . current ! ) ; } , [ animate ] ) ; return ( < GamepadsContext . Provider value = { { gamepads , setGamepads } } > { children } < /GamepadsContext.Provider>); } ; export { GamepadsProvider , GamepadsContext } ;