Use navigation sequencing for user activity handling

Better fix for #484

Tusker/AppDelegate.swift

@@ -292,12 +292,15 @@ extension AppDelegate: UNUserNotificationCenterDelegate {
            let rootViewController = delegate.rootViewController {
             let mastodonController = MastodonController.getForAccount(account)
             
-            // if the scene is already active, then we animate the account switching if necessary
-            delegate.activateAccount(account, animated: scene.activationState == .foregroundActive)
+            // if the scene is already active, then we animate things
+            let animated = scene.activationState == .foregroundActive
             
-            rootViewController.select(route: .notifications, animated: false) {
+            delegate.activateAccount(account, animated: animated)
+            
+            rootViewController.runNavigation(animated: animated) { navigation in
+                navigation.select(route: .notifications)
                 let vc = NotificationLoadingViewController(notificationID: notificationID, mastodonController: mastodonController)
-                rootViewController.getNavigationController().pushViewController(vc, animated: false)
+                navigation.push(viewController: vc)
             }
         } else {
             let activity = UserActivityManager.showNotificationActivity(id: notificationID, accountID: accountID)

Tusker/Scenes/MainSceneDelegate.swift

@@ -83,9 +83,7 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate, TuskerSceneDelegate
         } else {
             context = ActiveAccountUserActivityHandlingContext(isHandoff: true, root: rootViewController!)
         }
-        Task(priority: .userInitiated) {
-            _ = await userActivity.handleResume(manager: UserActivityManager(scene: scene as! UIWindowScene, context: context))
-        }
+        _ = userActivity.handleResume(manager: UserActivityManager(scene: scene as! UIWindowScene, context: context))
     }
     
     func windowScene(_ windowScene: UIWindowScene, performActionFor shortcutItem: UIApplicationShortcutItem, completionHandler: @escaping (Bool) -> Void) {
@@ -193,11 +191,9 @@ class MainSceneDelegate: UIResponder, UIWindowSceneDelegate, TuskerSceneDelegate
             
             if let activity = launchActivity {
                 func doRestoreActivity(context: UserActivityHandlingContext) {
-                    Task(priority: .userInitiated) {
-                        _ = await activity.handleResume(manager: UserActivityManager(scene: window!.windowScene!, context: context))
+                    _ = activity.handleResume(manager: UserActivityManager(scene: window!.windowScene!, context: context))
                     context.finalize(activity: activity)
                 }
-                }
                 if activity.isStateRestorationActivity {
                     doRestoreActivity(context: StateRestorationUserActivityHandlingContext(root: rootViewController!))
                 } else if activity.activityType != UserActivityType.mainScene.rawValue {

Tusker/Screens/Main/AccountSwitchingContainerViewController.swift

@@ -79,13 +79,11 @@ class AccountSwitchingContainerViewController: UIViewController {
                 stateRestorationLogger.debug("AccountSwitchingContainer: reusing existing VC for \(account.id, privacy: .public)")
             } else {
                 newRoot = newRootProvider()
-                Task(priority: .userInitiated) {
                 stateRestorationLogger.debug("AccountSwitchingContainer: restoring \(activity.activityType, privacy: .public) for \(account.id, privacy: .public)")
                 let context = StateRestorationUserActivityHandlingContext(root: newRoot)
-                    _ = await activity.handleResume(manager: UserActivityManager(scene: view.window!.windowScene!, context: context))
+                _ = activity.handleResume(manager: UserActivityManager(scene: view.window!.windowScene!, context: context))
                 context.finalize(activity: activity)
             }
-            }
         } else {
             newRoot = newRootProvider()
         }

Tusker/Screens/Main/MainSplitViewController.swift

@@ -333,14 +333,14 @@ extension MainSplitViewController: UISplitViewControllerDelegate {
             // Transfer the navigation stack, dropping the search VC, to keep anything the user has opened
             transferNavigationStack(from: .tab(.explore), to: exploreNav, dropFirst: true, append: true)
             
-            tabBarViewController.select(tab: .explore, dismissPresented: false)
+            tabBarViewController.select(tab: .explore, dismissPresented: false, animated: false)
             
         case let .tab(tab):
             // sidebar items that map 1 <-> 1 can be transferred directly
-            tabBarViewController.select(tab: tab, dismissPresented: false)
+            tabBarViewController.select(tab: tab, dismissPresented: false, animated: false)
 
         case .bookmarks, .favorites, .list(_), .savedHashtag(_), .savedInstance(_):
-            tabBarViewController.select(tab: .explore, dismissPresented: false)
+            tabBarViewController.select(tab: .explore, dismissPresented: false, animated: false)
             // Make sure the Explore VC doesn't show its search bar when it appears, in case the user was previously
             // in compact mode and performing a search.
             let exploreNav = tabBarViewController.viewController(for: .explore) as! UINavigationController

Tusker/Screens/Main/MainTabBarViewController.swift

@@ -54,19 +54,22 @@ class MainTabBarViewController: BaseMainTabBarViewController {
         view.backgroundColor = .appBackground
     }
     
-    func select(tab: Tab, dismissPresented: Bool) {
+    func select(tab: Tab, dismissPresented: Bool, animated: Bool, completion: (() -> Void)? = nil) {
         if tab == .compose {
-            compose(editing: nil)
+            compose(editing: nil, completion: completion)
         } else {
             // when switching tabs, dismiss the currently presented VC
             // otherwise the selected tab changes behind the presented VC
             if presentedViewController != nil && dismissPresented {
-                dismiss(animated: true) {
+                dismiss(animated: animated) {
+                    stateRestorationLogger.info("MainTabBarViewController: selecting \(String(describing: tab), privacy: .public)")
                     self.selectedIndex = tab.rawValue
+                    completion?()
                 }
             } else {
                 stateRestorationLogger.info("MainTabBarViewController: selecting \(String(describing: tab), privacy: .public)")
                 selectedIndex = tab.rawValue
+                completion?()
             }
         }
     }
@@ -151,25 +154,24 @@ extension MainTabBarViewController: TuskerRootViewController {
     func select(route: TuskerRoute, animated: Bool, completion: (() -> Void)?) {
         switch route {
         case .timelines:
-            select(tab: .timelines, dismissPresented: true)
+            select(tab: .timelines, dismissPresented: true, animated: animated, completion: completion)
         case .notifications:
-            select(tab: .notifications, dismissPresented: true)
+            select(tab: .notifications, dismissPresented: true, animated: animated, completion: completion)
         case .myProfile:
-            select(tab: .myProfile, dismissPresented: true)
+            select(tab: .myProfile, dismissPresented: true, animated: animated, completion: completion)
         case .explore:
-            select(tab: .explore, dismissPresented: true)
+            select(tab: .explore, dismissPresented: true, animated: animated, completion: completion)
         case .bookmarks:
-            select(tab: .explore, dismissPresented: true)
+            select(tab: .explore, dismissPresented: true, animated: animated, completion: completion)
             getNavigationController().pushViewController(BookmarksViewController(mastodonController: mastodonController), animated: animated)
         case .list(id: let id):
-            select(tab: .explore, dismissPresented: true)
+            select(tab: .explore, dismissPresented: true, animated: animated, completion: completion)
             if let list = mastodonController.getCachedList(id: id) {
                 let nav = getNavigationController()
                 _ = nav.popToRootViewController(animated: animated)
                 nav.pushViewController(ListTimelineViewController(for: list, mastodonController: mastodonController), animated: animated)
             }
         }
-        completion?()
     }
     
     func getNavigationDelegate() -> TuskerNavigationDelegate? {
@@ -186,7 +188,7 @@ extension MainTabBarViewController: TuskerRootViewController {
             return
         }
         
-        select(tab: .explore, dismissPresented: true)
+        select(tab: .explore, dismissPresented: true, animated: false)
         exploreNavController.popToRootViewController(animated: false)
         
         // setting searchController.isActive directly doesn't work until the view has loaded/appeared for the first time

Tusker/Screens/Main/TuskerRootViewController.swift

@@ -20,6 +20,14 @@ protocol TuskerRootViewController: UIViewController, StateRestorableViewControll
     func presentPreferences(completion: (() -> Void)?) -> PreferencesNavigationController?
 }
 
+extension TuskerRootViewController {
+    func runNavigation(animated: Bool, _ builder: (_ navigation: TuskerNavigationSequence) -> Void) {
+        let sequence = TuskerNavigationSequence(root: self, animated: animated)
+        builder(sequence)
+        sequence.run()
+    }
+}
+
 enum TuskerRoute {
     case timelines
     case notifications
@@ -29,6 +37,67 @@ enum TuskerRoute {
     case list(id: String)
 }
 
+/// A class that manages running a sequence of navigation operations on a ``TuskerRootViewController``.
+///
+/// Use this type, rather than calling multiple methods on the root VC in a row, because it manages waiting until each previous step finishes.
+@MainActor
+final class TuskerNavigationSequence {
+    private let root: any TuskerRootViewController
+    private let animated: Bool
+    private var operations = [() -> Void]()
+    
+    init(root: any TuskerRootViewController, animated: Bool) {
+        self.root = root
+        self.animated = animated
+    }
+    
+    func select(route: TuskerRoute) {
+        operations.append {
+            self.root.select(route: route, animated: self.animated, completion: self.run)
+        }
+    }
+    
+    func push(viewController: UIViewController) {
+        operations.append {
+            let nav = self.root.getNavigationController()
+            nav.pushViewController(viewController, animated: self.animated)
+            self.run()
+        }
+    }
+    
+    func popToRoot() {
+        operations.append {
+            let nav = self.root.getNavigationController()
+            nav.popToRootViewController(animated: self.animated)
+            self.run()
+        }
+    }
+    
+    func present(viewController: UIViewController) {
+        operations.append {
+            self.root.present(viewController, animated: self.animated, completion: self.run)
+        }
+    }
+    
+    func withTopViewController(_ block: @escaping (_ topViewController: UIViewController?, _ completion: @escaping @MainActor () -> Void) -> Void) {
+        operations.append {
+            block(self.root.getNavigationController().topViewController, self.run)
+        }
+    }
+    
+    func addOperation(_ operation: @escaping (_ completion: @escaping () -> Void) -> Void) {
+        operations.append {
+            operation(self.run)
+        }
+    }
+    
+    func run() {
+        if !operations.isEmpty {
+            operations.removeFirst()()
+        }
+    }
+}
+
 @MainActor
 protocol NavigationControllerProtocol: UIViewController {
     var viewControllers: [UIViewController] { get set }

Tusker/Shortcuts/NSUserActivity+Extensions.swift

@@ -43,9 +43,9 @@ extension NSUserActivity {
     }
     
     @MainActor
-    func handleResume(manager: UserActivityManager) async -> Bool {
+    func handleResume(manager: UserActivityManager) -> Bool {
         guard let type = UserActivityType(rawValue: activityType) else { return false }
-        await type.handle(manager)(self)
+        type.handle(manager)(self)
         return true
     }
     

Tusker/Shortcuts/UserActivityHandlingContext.swift

@@ -16,93 +16,94 @@ import ComposeUI
 protocol UserActivityHandlingContext {
     var isHandoff: Bool { get }
     
-    func select(route: TuskerRoute) async
-    func select(route: TuskerRoute, completion: (() -> Void)?)
-    func present(_ vc: UIViewController)
-    
-    var topViewController: UIViewController? { get }
+    func select(route: TuskerRoute)
     func popToRoot()
     func push(_ vc: UIViewController)
+    func withTopViewController(_ block: @escaping (_ topViewController: UIViewController?, _ completion: @escaping @MainActor () -> Void) -> Void)
 
+    func present(_ vc: UIViewController)
     func compose(editing draft: Draft)
     
     func finalize(activity: NSUserActivity)
 }
 
-extension UserActivityHandlingContext {
-    func select(route: TuskerRoute) async {
-        await withCheckedContinuation { continuation in
-            select(route: route) {
-                continuation.resume()
-            }
-        }
-    }
-}
-
 struct ActiveAccountUserActivityHandlingContext: UserActivityHandlingContext {
     let isHandoff: Bool
-    let root: TuskerRootViewController
-    var navigationDelegate: TuskerNavigationDelegate {
-        root.getNavigationDelegate()!
+    private let root: TuskerRootViewController
+    private let navigation: TuskerNavigationSequence
+    
+    init(isHandoff: Bool, root: TuskerRootViewController) {
+        self.isHandoff = isHandoff
+        self.root = root
+        self.navigation = TuskerNavigationSequence(root: root, animated: true)
     }
     
-    func select(route: TuskerRoute, completion: (() -> Void)?) {
-        root.select(route: route, animated: true, completion: completion)
+    func select(route: TuskerRoute) {
+        navigation.select(route: route)
     }
     
     func present(_ vc: UIViewController) {
-        navigationDelegate.present(vc, animated: true)
+        navigation.present(viewController: vc)
     }
     
-    var topViewController: UIViewController? { root.getNavigationController().topViewController }
-    
     func popToRoot() {
-        _ = root.getNavigationController().popToRootViewController(animated: true)
+        navigation.popToRoot()
     }
     
     func push(_ vc: UIViewController) {
-        navigationDelegate.show(vc, sender: nil)
+        navigation.push(viewController: vc)
+    }
+    
+    func withTopViewController(_ block: @escaping (_ topViewController: UIViewController?, _ completion: @escaping @MainActor () -> Void) -> Void) {
+        navigation.withTopViewController(block)
     }
 
     func compose(editing draft: Draft) {
-        navigationDelegate.compose(editing: draft, animated: true, isDucked: true)
+        navigation.addOperation { completion in
+            root.compose(editing: draft, animated: true, isDucked: true, completion: completion)
+        }
     }
     
     func finalize(activity: NSUserActivity) {
+        navigation.run()
     }
 }
 
 class StateRestorationUserActivityHandlingContext: UserActivityHandlingContext {
     private var state = State.initial
-    let root: TuskerRootViewController
+    private let root: TuskerRootViewController
+    private let navigation: TuskerNavigationSequence
     
     init(root: TuskerRootViewController) {
         self.root = root
+        self.navigation = TuskerNavigationSequence(root: root, animated: false)
     }
     
-    var isHandoff: Bool { false }
-    
-    func select(route: TuskerRoute, completion: (() -> Void)?) {
-        root.select(route: route, animated: false) {
-            self.state = .selectedRoute
-            completion?()
-        }
+    var isHandoff: Bool {
+        false
     }
     
-    var topViewController: UIViewController? { root.getNavigationController().topViewController }
+    func select(route: TuskerRoute) {
+        navigation.select(route: route)
+        state = .selectedRoute
+    }
     
     func popToRoot() {
-        // unnecessary during state restoration
+        navigation.popToRoot()
     }
     
     func push(_ vc: UIViewController) {
         precondition(state >= .selectedRoute)
-        root.getNavigationController().pushViewController(vc, animated: false)
+        navigation.push(viewController: vc)
         state = .pushed
     }
     
+    func withTopViewController(_ block: @escaping (_ topViewController: UIViewController?, _ completion: @escaping @MainActor () -> Void) -> Void) {
+        navigation.withTopViewController(block)
+    }
+
     func present(_ vc: UIViewController) {
-        root.present(vc, animated: false)
+        navigation.present(viewController: vc)
         state = .presented
     }
     
@@ -120,6 +121,7 @@ class StateRestorationUserActivityHandlingContext: UserActivityHandlingContext {
     
     func finalize(activity: NSUserActivity) {
         precondition(state > .initial)
+        navigation.run()
         #if !os(visionOS)
         if #available(iOS 16.0, *),
            let duckedDraft = UserActivityManager.getDuckedDraft(from: activity) {

Tusker/Shortcuts/UserActivityManager.swift

@@ -133,13 +133,16 @@ class UserActivityManager {
         return activity
     }
     
-    func handleCheckNotifications(activity: NSUserActivity) async {
-        await context.select(route: .notifications)
+    func handleCheckNotifications(activity: NSUserActivity) {
+        context.select(route: .notifications)
         context.popToRoot()
-        if let notificationsPageController = context.topViewController as? NotificationsPageViewController {
+        context.withTopViewController { topViewController, completion in
+            if let notificationsPageController = topViewController as? NotificationsPageViewController {
                 notificationsPageController.loadViewIfNeeded()
                 notificationsPageController.selectMode(Self.getNotificationsMode(from: activity) ?? Preferences.shared.defaultNotificationsMode)
             }
+            completion()
+        }
     }
     
     static func getNotificationsMode(from activity: NSUserActivity) -> NotificationsMode? {
@@ -204,32 +207,41 @@ class UserActivityManager {
         return (timeline, positionInfo)
     }
     
-    func handleShowTimeline(activity: NSUserActivity) async {
+    func handleShowTimeline(activity: NSUserActivity) {
         guard let (timeline, positionInfo) = Self.getTimeline(from: activity) else { return }
         
-        var timelineVC: TimelineViewController?
         if let pinned = PinnedTimeline(timeline: timeline),
            mastodonController.accountPreferences.pinnedTimelines.contains(pinned) {
-            await context.select(route: .timelines)
+            context.select(route: .timelines)
             context.popToRoot()
-            let pageController = context.topViewController as! TimelinesPageViewController
+            context.withTopViewController { topViewController, completion in
+                let pageController = topViewController as! TimelinesPageViewController
                 pageController.selectTimeline(pinned, animated: false)
-            timelineVC = pageController.currentViewController as? TimelineViewController
+            }
         } else if case .list(let id) = timeline {
-            await context.select(route: .list(id: id))
-            timelineVC = context.topViewController as? TimelineViewController
+            context.select(route: .list(id: id))
         } else {
-            await context.select(route: .explore)
+            context.select(route: .explore)
             context.popToRoot()
-            timelineVC = TimelineViewController(for: timeline, mastodonController: mastodonController)
-            context.push(timelineVC!)
+            let timelineVC = TimelineViewController(for: timeline, mastodonController: mastodonController)
+            context.push(timelineVC)
         }
         
-        if let timelineVC,
-           let positionInfo,
+        if let positionInfo,
            context.isHandoff {
+            context.withTopViewController { topViewController, completion in
+                let timelineVC: TimelineViewController
+                if let topViewController = topViewController as? TimelineViewController {
+                    timelineVC = topViewController
+                } else if let topViewController = topViewController as? TimelinesPageViewController {
+                    timelineVC = topViewController.currentViewController as! TimelineViewController
+                } else {
+                    return
+                }
                 Task {
                     await timelineVC.restoreStateFromHandoff(statusIDs: positionInfo.statusIDs, centerStatusID: positionInfo.centerStatusID)
+                    completion()
+                }
             }
         }
     }
@@ -249,11 +261,11 @@ class UserActivityManager {
         return activity.userInfo?["mainStatusID"] as? String
     }
     
-    func handleShowConversation(activity: NSUserActivity) async {
+    func handleShowConversation(activity: NSUserActivity) {
         guard let mainStatusID = Self.getConversationStatus(from: activity) else {
             return
         }
-        await context.select(route: .timelines)
+        context.select(route: .timelines)
         context.push(ConversationViewController(for: mainStatusID, state: .unknown, mastodonController: mastodonController))
     }
     
@@ -274,18 +286,19 @@ class UserActivityManager {
         return activity.userInfo?["query"] as? String
     }
     
-    func handleSearch(activity: NSUserActivity) async {
-        await context.select(route: .explore)
+    func handleSearch(activity: NSUserActivity) {
+        context.select(route: .explore)
         context.popToRoot()
         
+        context.withTopViewController { topViewController, completion in
             let searchController: UISearchController
             let resultsController: SearchResultsViewController
-        if let explore = context.topViewController as? ExploreViewController {
+            if let explore = topViewController as? ExploreViewController {
                 explore.loadViewIfNeeded()
                 explore.searchControllerStatusOnAppearance = true
                 searchController = explore.searchController
                 resultsController = explore.resultsController
-        } else if let inlineTrends = context.topViewController as? InlineTrendsViewController {
+            } else if let inlineTrends = topViewController as? InlineTrendsViewController {
                 inlineTrends.loadViewIfNeeded()
                 inlineTrends.searchControllerStatusOnAppearance = true
                 searchController = inlineTrends.searchController
@@ -302,6 +315,7 @@ class UserActivityManager {
                 searchController.searchBar.becomeFirstResponder()
             }
         }
+    }
 
     static func bookmarksActivity(accountID: String) -> NSUserActivity {
         let activity = NSUserActivity(type: .bookmarks, accountID: accountID)
@@ -311,8 +325,8 @@ class UserActivityManager {
         return activity
     }
     
-    func handleBookmarks(activity: NSUserActivity) async {
-        await context.select(route: .bookmarks)
+    func handleBookmarks(activity: NSUserActivity) {
+        context.select(route: .bookmarks)
     }
     
     // MARK: - My Profile
@@ -325,8 +339,8 @@ class UserActivityManager {
         return activity
     }
     
-    func handleMyProfile(activity: NSUserActivity) async {
-        await context.select(route: .myProfile)
+    func handleMyProfile(activity: NSUserActivity) {
+        context.select(route: .myProfile)
     }
     
     // MARK: - Show Profile
@@ -344,11 +358,11 @@ class UserActivityManager {
         return activity.userInfo?["profileID"] as? String
     }
     
-    func handleShowProfile(activity: NSUserActivity) async {
+    func handleShowProfile(activity: NSUserActivity) {
         guard let accountID = Self.getProfile(from: activity) else {
             return
         }
-        await context.select(route: .timelines)
+        context.select(route: .timelines)
         context.push(ProfileViewController(accountID: accountID, mastodonController: mastodonController))
     }
     
@@ -361,11 +375,11 @@ class UserActivityManager {
         return activity
     }
     
-    func handleShowNotification(activity: NSUserActivity) async {
+    func handleShowNotification(activity: NSUserActivity) {
         guard let notificationID = activity.userInfo?["notificationID"] as? String else {
             return
         }
-        await context.select(route: .notifications)
+        context.select(route: .notifications)
         context.push(NotificationLoadingViewController(notificationID: notificationID, mastodonController: mastodonController))
     }
     

Tusker/Shortcuts/UserActivityType.swift

@@ -23,7 +23,7 @@ enum UserActivityType: String {
 
 extension UserActivityType {
     @MainActor
-    var handle: (UserActivityManager) -> @MainActor (NSUserActivity) async -> Void {
+    var handle: (UserActivityManager) -> @MainActor (NSUserActivity) -> Void {
         switch self {
         case .mainScene:
             fatalError("cannot handle main scene activity")