Fix passcode not shown

- add small dismiss animation

Instead of modally displaying the passcode on top of the current VC use the privacy window to display the passcode on top of it.
This allows us to keep whatever VCs are below that intact and active (including system modals like QuickLook markup, Photo select, UIActivityVC, etc.), because the window can be displayed on top of everything (even alerts).
It also improves privacy, because tho the blur effect on top of whatever file is opened looks kinda cool, the purpose of adding a passcode is so that others can't see my files. The blur view gave away more information about what files are there / how many.

Signed-off-by: Henrik Storch <henrik.storch@nextcloud.com>

iOSClient/AppDelegate.swift

@@ -188,14 +188,12 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
 
     // L' applicazione entrerà in primo piano (attivo sempre)
     func applicationDidBecomeActive(_ application: UIApplication) {
-        
+
         if !NCAskAuthorization.shared.isRequesting {
             // Privacy
             hidePrivacyProtectionWindow()
         }
-        
-        NCSettingsBundleHelper.setVersionAndBuildNumber()
-        
+
         NCSettingsBundleHelper.setVersionAndBuildNumber()
 
         if account == "" { return }
@@ -247,9 +245,11 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
 
         if account == "" { return }
 
-        // Privacy
-        showPrivacyProtectionWindow()
-                
+        if CCUtility.getPrivacyScreenEnabled() {
+            // Privacy
+            showPrivacyProtectionWindow()
+        }
+
         // Clear operation queue
         NCOperationQueue.shared.cancelAllQueue()
         // Clear download
@@ -268,20 +268,20 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     func applicationDidEnterBackground(_ application: UIApplication) {
 
         if account == "" { return }
-        
+
         // STOP TIMER UPLOAD PROCESS
         if NCUtility.shared.isSimulator() {
             networkingProcessUpload?.stopTimer()
         }
-                
+
         if #available(iOS 13.0, *) {
             scheduleAppRefresh()
             scheduleBackgroundProcessing()
         }
-        
+
         // Passcode
         presentPasscode { }
-        
+
         NotificationCenter.default.postOnMainThread(name: NCGlobal.shared.notificationCenterApplicationDidEnterBackground)
     }
 
@@ -299,7 +299,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
         if account == "" { return }
 
         NCCommunicationCommon.shared.writeLog("initialize Main")
-                
+
         // Registeration push notification
         NCPushNotification.shared().pushNotification()
 
@@ -657,17 +657,16 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     // MARK: - Account Request
 
     func accountRequestChangeAccount(account: String) {
-
         changeAccount(account)
     }
     
     func requestAccount() {
-              
+
         if isPasscodePresented() { return }
         if !CCUtility.getAccountRequest() { return }
-        
+
         let accounts = NCManageDatabase.shared.getAllAccount()
-        
+
         if accounts.count > 1 {
             
             if let vcAccountRequest = UIStoryboard(name: "NCAccountRequest", bundle: nil).instantiateInitialViewController() as? NCAccountRequest {
@@ -694,30 +693,21 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     }
 
     // MARK: - Passcode
-    
+
     func presentPasscode(completion: @escaping () -> ()) {
 
         let laContext = LAContext()
         var error: NSError?
 
-        defer {
-            self.requestAccount()
-        }
-
-        guard !account.isEmpty, CCUtility.isPasscodeAtStartEnabled() else { return }
-        
-        // If activated hide the privacy protection
-        hidePrivacyProtectionWindow()
+        defer { self.requestAccount() }
 
-        // Dismiss present window?.rootViewController? [ONLY PASSCODE]
         let presentedViewController = window?.rootViewController?.presentedViewController
-        if presentedViewController is NCLoginNavigationController {
-            return
-        } else {
-            presentedViewController?.dismiss(animated: false)
-        }
+        guard !account.isEmpty, CCUtility.isPasscodeAtStartEnabled(), !(presentedViewController is NCLoginNavigationController) else { return }
+
+        // Make sure we have a privacy window (in case it's not enabled)
+        showPrivacyProtectionWindow()
 
-        let passcodeViewController = TOPasscodeViewController.init(passcodeType: .sixDigits, allowCancel: false)
+        let passcodeViewController = TOPasscodeViewController(passcodeType: .sixDigits, allowCancel: false)
         passcodeViewController.delegate = self
         passcodeViewController.keypadButtonShowLettering = false
         if CCUtility.getEnableTouchFaceID() && laContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
@@ -731,8 +721,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
                 passcodeViewController.automaticallyPromptForBiometricValidation = false
             }
         }
-        
-        window?.rootViewController?.present(passcodeViewController, animated: true, completion: {
+
+        // show passcode on top of privacy window
+        privacyProtectionWindow?.rootViewController?.present(passcodeViewController, animated: true, completion: {
             completion()
         })
     }
@@ -763,6 +754,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     func didInputCorrectPasscode(in passcodeViewController: TOPasscodeViewController) {
         DispatchQueue.main.async {
             passcodeViewController.dismiss(animated: true) {
+                self.hidePrivacyProtectionWindow()
                 self.requestAccount()
             }
         }
@@ -775,23 +767,30 @@ class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterD
     // MARK: - Privacy Protection
        
     private func showPrivacyProtectionWindow() {
-        
-        guard CCUtility.getPrivacyScreenEnabled() else { return }
-        
+        guard privacyProtectionWindow == nil else {
+            privacyProtectionWindow?.isHidden = false
+            return
+        }
+
         privacyProtectionWindow = UIWindow(frame: UIScreen.main.bounds)
-          
+
         let storyboard = UIStoryboard(name: "LaunchScreen", bundle: nil)
         let initialViewController = storyboard.instantiateInitialViewController()
 
         self.privacyProtectionWindow?.rootViewController = initialViewController
-        
+
         privacyProtectionWindow?.windowLevel = .alert + 1
         privacyProtectionWindow?.makeKeyAndVisible()
     }
 
     func hidePrivacyProtectionWindow() {
-        privacyProtectionWindow?.isHidden = true
-        privacyProtectionWindow = nil
+        guard !(privacyProtectionWindow?.rootViewController?.presentedViewController is TOPasscodeViewController) else { return }
+        UIWindow.animate(withDuration: 0.25) {
+            self.privacyProtectionWindow?.alpha = 0
+        } completion: { _ in
+            self.privacyProtectionWindow?.isHidden = true
+            self.privacyProtectionWindow = nil
+        }
     }
     
     // MARK: - Open URL