import { useEffect } from '../lib/teact/teact'; export default function useBackgroundMode( onBlur?: AnyToVoidFunction, onFocus?: AnyToVoidFunction, ) { useEffect(() => { if (onBlur && !document.hasFocus()) { onBlur(); } if (onBlur) { window.addEventListener('blur', onBlur); } if (onFocus) { window.addEventListener('focus', onFocus); } return () => { if (onFocus) { window.removeEventListener('focus', onFocus); } if (onBlur) { window.removeEventListener('blur', onBlur); } }; }, [onBlur, onFocus]); }