Switches to UIScene-based lifecycle

AltStore/SceneDelegate.swift

@@ -0,0 +1,52 @@
+//
+//  SceneDelegate.swift
+//  AltStore
+//
+//  Created by Riley Testut on 7/6/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import UIKit
+import AltStoreCore
+
+@available(iOS 13, *)
+class SceneDelegate: UIResponder, UIWindowSceneDelegate
+{
+    var window: UIWindow?
+
+    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions)
+    {
+        // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
+        // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
+        // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
+        guard let _ = (scene as? UIWindowScene) else { return }
+    }
+
+    func sceneWillEnterForeground(_ scene: UIScene)
+    {
+        // Called as the scene transitions from the background to the foreground.
+        // Use this method to undo the changes made on entering the background.
+        
+        // applicationWillEnterForeground is _not_ called when launching app,
+        // whereas sceneWillEnterForeground _is_ called when launching.
+        // As a result, DatabaseManager might not be started yet, so just return if it isn't
+        // (since all these methods are called separately during app startup).
+        guard DatabaseManager.shared.isStarted else { return }
+        
+        AppManager.shared.update()
+        ServerManager.shared.startDiscovering()
+        
+        PatreonAPI.shared.refreshPatreonAccount()
+    }
+    
+    func sceneDidEnterBackground(_ scene: UIScene)
+    {
+        // Called as the scene transitions from the foreground to the background.
+        // Use this method to save data, release shared resources, and store enough scene-specific state information
+        // to restore the scene back to its current state.
+        
+        guard UIApplication.shared.applicationState == .background else { return }
+        
+        ServerManager.shared.stopDiscovering()
+    }
+}