[iOS - swift] safeArea 크기 구하는 방법(#'keyWindow' was deprecated in iOS 13.0, #safeAreaInsets)

safe area 경고 표출

• 보통 아래처럼 keyWindow로 구하면 warning 문구가 표출

// 'keyWindow' was deprecated in iOS 13.0: Should not be used for applications that support multiple scenes as it returns a key window across all connected scenes
let window = UIApplication.shared.keyWindow
let safeAreaInsets = window?.safeAreaInsets

• iOS 13부터 Scene이라는 개념이 생겼는데, 이 scene에 접근해서 window를 가져와야함

safeAreaInset 구하는 방법

• connectedScenes에 접근하여 첫번째 scene 가져오기

let connectedScene = UIApplication.shared.connectedScenes.first

• UIWindowScene으로 캐스팅

let windowScene = connectedScene as? UIWindowScene

• 첫번째 window 가져오기

let window = windowScene?.windows.first

• safeAreaInset 획득

let safeAreaInset = window?.safeAreaInsets ?? .zero
print(safeAreaInset) // UIEdgeInsets(top: 59.0, left: 0.0, bottom: 34.0, right: 0.0)

• 고차함수를 사용하여 표현

let safeAreaInset = UIApplication.shared.connectedScenes.first
    .flatMap { ($0 as? UIWindowScene)?.windows.first }?
    .flatMap { $0.safeAreaInsets }