handle access to selected photos & optimise the process of request photo library permission

Session/Conversations/ConversationVC+Interaction.swift

@@ -92,12 +92,14 @@ extension ConversationVC : InputViewDelegate, MessageCellDelegate, ContextMenuAc
     }
     
     func handleLibraryButtonTapped() {
-        // FIXME: We're not yet handling the case where the user only gives access to selected photos/videos
-        guard requestLibraryPermissionIfNeeded() else { return }
+        requestLibraryPermissionIfNeeded { [weak self] in
+            DispatchQueue.main.async {
                 let sendMediaNavController = SendMediaNavigationController.showingMediaLibraryFirst()
                 sendMediaNavController.sendMediaNavDelegate = self
                 sendMediaNavController.modalPresentationStyle = .fullScreen
-        present(sendMediaNavController, animated: true, completion: nil)
+                self?.present(sendMediaNavController, animated: true, completion: nil)
+            }
+        }
     }
     
     func handleGIFButtonTapped() {
@@ -727,43 +729,46 @@ extension ConversationVC : InputViewDelegate, MessageCellDelegate, ContextMenuAc
         }
     }
 
-    func requestLibraryPermissionIfNeeded() -> Bool {
+    func requestLibraryPermissionIfNeeded(handler: @escaping () -> Void) {
         let authorizationStatus: PHAuthorizationStatus
         if #available(iOS 14, *) {
             authorizationStatus = PHPhotoLibrary.authorizationStatus(for: .readWrite)
             if (authorizationStatus == .notDetermined) {
-                PHPhotoLibrary.requestAuthorization(for: .readWrite) { newStatus in
-                    switch newStatus {
-                    case .authorized:
-                        print("RYAN: Full access.")
-                        break
-                    case .limited:
-                        print("RYAN: Limited access.")
-                        break
-                    case .denied:
-                        break
-                    default:
-                        break
+                // When the user chooses to select photos (which is the .limit status),
+                // the PHPhotoUI will present the picker view on the top of the front view.
+                // Since we have this ScreenLockUI showing when we request premissions,
+                // the picker view will be presented on the top of ScreenLockUI.
+                // However, the ScreenLockUI will dismiss with the permission request alert view,
+                // the picker view then will dissmiss, too. The selection process cannot be finished
+                // this way. So we add a flag (isRequestingPermission) to prevent the ScreenLockUI
+                // from showing when we request the photo library permission.
+                Environment.shared.isRequestingPermission = true
+                PHPhotoLibrary.requestAuthorization(for: .readWrite) { status in
+                    Environment.shared.isRequestingPermission = false
+                    if ([PHAuthorizationStatus.authorized, PHAuthorizationStatus.limited].contains(status)) {
+                        handler()
                     }
                 }
-                return false
             }
         } else {
             authorizationStatus = PHPhotoLibrary.authorizationStatus()
             if (authorizationStatus == .notDetermined) {
-                PHPhotoLibrary.requestAuthorization { _ in }
-                return false
+                PHPhotoLibrary.requestAuthorization { status in
+                    if (status == .authorized) {
+                        handler()
+                    }
+                }
             }
         }
         switch authorizationStatus {
-        case .authorized, .limited: return true
+        case .authorized, .limited:
+            handler()
         case .denied, .restricted:
             let modal = PermissionMissingModal(permission: "library") { }
             modal.modalPresentationStyle = .overFullScreen
             modal.modalTransitionStyle = .crossDissolve
             present(modal, animated: true, completion: nil)
-            return false
-        default: return false
+        default: return
         }
     }
 

Session/Shared/OWSScreenLockUI.m

@@ -348,6 +348,10 @@ NS_ASSUME_NONNULL_BEGIN
         return ScreenLockUIStateNone;
     }
     
+    if (Environment.shared.isRequestingPermission) {
+        return ScreenLockUIStateNone;
+    }
+
     if (Environment.shared.preferences.screenSecurityIsEnabled) {
         OWSLogVerbose(@"desiredUIState: screen protection 4.");
         return ScreenLockUIStateScreenProtection;

SessionMessagingKit/Utilities/Environment.h

@@ -29,6 +29,8 @@
 @property (nonatomic, readonly) OWSPreferences *preferences;
 @property (nonatomic, readonly) OWSSounds *sounds;
 @property (nonatomic, readonly) OWSWindowManager *windowManager;
+// We don't want to cover the window when we request the photo library permission
+@property (nonatomic, readwrite) BOOL isRequestingPermission;
 
 @property (class, nonatomic) Environment *shared;
 

SessionMessagingKit/Utilities/Environment.m

@@ -58,6 +58,7 @@ static Environment *sharedEnvironment = nil;
     _proximityMonitoringManager = proximityMonitoringManager;
     _sounds = sounds;
     _windowManager = windowManager;
+    _isRequestingPermission = false;
 
     return self;
 }