[Add] #244 - notificationCenter & UIApplication extension 추가

iOS-NOTTODO/iOS-NOTTODO/Global/Extensions/NotificationCenter.swift

@@ -0,0 +1,34 @@
+//
+//  NotificationCenter.swift
+//  iOS-NOTTODO
+//
+//  Created by JEONGEUN KIM on 3/21/24.
+//
+
+import UIKit
+import Combine
+
+extension NotificationCenter {
+
+    enum Notification {
+        case willEnterForeground
+        case didEnterBackground
+    }
+
+    var willEnterForeground: AnyPublisher<NotificationCenter.Notification, Never> {
+        publisher(for: UIApplication.willEnterForegroundNotification)
+            .map { _ in return .willEnterForeground }
+            .eraseToAnyPublisher()
+    }
+
+    var didEnterBackground: AnyPublisher<NotificationCenter.Notification, Never> {
+        publisher(for: UIApplication.didEnterBackgroundNotification)
+            .map { _ in return .didEnterBackground }
+            .eraseToAnyPublisher()
+    }
+
+    var applicationState: AnyPublisher<NotificationCenter.Notification, Never> {
+        Publishers.Merge(willEnterForeground, didEnterBackground)
+            .eraseToAnyPublisher()
+    }
+}

iOS-NOTTODO/iOS-NOTTODO/Global/Extensions/UIApplication+.swift

@@ -0,0 +1,29 @@
+//
+//  UIApplication+.swift
+//  iOS-NOTTODO
+//
+//  Created by JEONGEUN KIM on 3/21/24.
+//
+
+import UIKit
+
+extension UIApplication {
+    private static let notificationSettingsURL: URL? = {
+        let settingsString: String
+        if #available(iOS 16, *) {
+            settingsString = UIApplication.openNotificationSettingsURLString
+        } else if #available(iOS 15.4, *) {
+            settingsString = UIApplicationOpenNotificationSettingsURLString
+        } else {
+            settingsString = UIApplication.openSettingsURLString
+        }
+        return URL(string: settingsString)
+    }()
+
+    func openAppNotificationSettings() {
+        guard
+            let url = UIApplication.notificationSettingsURL,
+            self.canOpenURL(url) else { return }
+        return open(url)
+    }
+}