Use navigation sequencing for user activity handling

Tusker/Screens/Main/TuskerRootViewController.swift

@@ -42,8 +42,8 @@ enum TuskerRoute {
 /// 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 {
-    let root: any TuskerRootViewController
+    private let root: any TuskerRootViewController
-    let animated: Bool
+    private let animated: Bool
     private var operations = [() -> Void]()
     
     init(root: any TuskerRootViewController, animated: Bool) {
@@ -73,6 +73,24 @@ final class TuskerNavigationSequence {
         }
     }
     
+    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()()

Tusker/Shortcuts/UserActivityHandlingContext.swift

@@ -17,12 +17,11 @@ protocol UserActivityHandlingContext {
     var isHandoff: Bool { get }
     
     func select(route: TuskerRoute)
-    func present(_ vc: UIViewController)
-    
-    var topViewController: UIViewController? { get }
     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)
@@ -30,66 +29,81 @@ protocol UserActivityHandlingContext {
 
 struct ActiveAccountUserActivityHandlingContext: UserActivityHandlingContext {
     let isHandoff: Bool
-    let root: TuskerRootViewController
+    private let root: TuskerRootViewController
-    var navigationDelegate: TuskerNavigationDelegate {
+    private let navigation: TuskerNavigationSequence
-        root.getNavigationDelegate()!
+    
+    init(isHandoff: Bool, root: TuskerRootViewController) {
+        self.isHandoff = isHandoff
+        self.root = root
+        self.navigation = TuskerNavigationSequence(root: root, animated: true)
     }
     
     func select(route: TuskerRoute) {
-        root.select(route: route, animated: true, completion: nil)
+        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 }
+    var isHandoff: Bool {
+        false
+    }
     
     func select(route: TuskerRoute) {
-        root.select(route: route, animated: false, completion: nil)
+        navigation.select(route: route)
         state = .selectedRoute
     }
     
-    var topViewController: UIViewController? { root.getNavigationController().topViewController }
-    
     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
     }
     
@@ -107,6 +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

@@ -136,10 +136,13 @@ class UserActivityManager {
     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? {
@@ -207,29 +210,38 @@ class UserActivityManager {
     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) {
             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 {
             context.select(route: .list(id: id))
-            timelineVC = context.topViewController as? TimelineViewController
         } else {
             context.select(route: .explore)
             context.popToRoot()
-            timelineVC = TimelineViewController(for: timeline, mastodonController: mastodonController)
+            let timelineVC = TimelineViewController(for: timeline, mastodonController: mastodonController)
-            context.push(timelineVC!)
+            context.push(timelineVC)
         }
         
-        if let timelineVC,
+        if let positionInfo,
-           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()
+                }
             }
         }
     }
@@ -278,14 +290,15 @@ class UserActivityManager {
         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)