네비게이션 바 fade animation

extension HomeViewController: UIScrollViewDelegate { func scrollViewDidScroll(_ scrollView: UIScrollView) { //스크롤뷰의 현재 위치 let offset = scrollView.contentOffset.y //MARK: 이미지 stick to top 애니메이션 if offset < 0 { slideShow.heightConstraint?.constant = 240 - offset headerTopConstraint.constant = offset } else { slideShow.heightConstraint?.constant = 240 } //MARK: 네비게이션 바 fade animation var proportionalOffset = offset / 60 if proportionalOffset > 1 { proportionalOffset = 1 let color = UIColor(red: 1, green: 1, blue: 1, alpha: proportionalOffset) self.navigationController?.navigationBar.tintColor = UIColor(hue: 1, saturation: 0, brightness: 1 - proportionalOffset, alpha: 1) self.navigationController?.navigationBar.backgroundColor = color UIApplication.statusBarBackgroundColor = color } else { let color = UIColor(red: 1, green: 1, blue: 1, alpha: proportionalOffset) self.navigationController?.navigationBar.tintColor = UIColor(hue: 1, saturation: 0, brightness: 1 - proportionalOffset, alpha: 1) self.navigationController?.navigationBar.backgroundColor = color UIApplication.statusBarBackgroundColor = color } } }