Add loading animation while syncing timeline position

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -213,12 +213,10 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         clearSelectionOnAppear(animated: animated)
         
         if case .notLoadedInitial = controller.state {
-            if restoreState() {
-                Task {
+            Task {
+                if await restoreState() {
                     await checkPresent(jumpImmediately: false)
-                }
-            } else {
-                Task {
+                } else {
                     await controller.loadInitial()
                 }
             }
@@ -329,18 +327,16 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         return activity
     }
     
-    func restoreState() -> Bool {
+    func restoreState() async -> Bool {
         guard persistsState,
               Preferences.shared.timelineStateRestoration,
               let position = mastodonController.persistentContainer.getTimelinePosition(timeline: timeline) else {
             return false
         }
         loadViewIfNeeded()
-        Task {
-            await controller.restoreInitial {
-                await loadStatusesToRestore(position: position)
-                applyItemsToRestore(position: position)
-            }
+        await controller.restoreInitial {
+            await loadStatusesToRestore(position: position)
+            applyItemsToRestore(position: position)
         }
         return true
     }
@@ -492,15 +488,29 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
             return false
         }
         if !alwaysPrompt {
-            _ = self.restoreState()
+            Task {
+                _ = await restoreState()
+            }
         } else {
             var config = ToastConfiguration(title: "Sync Position")
             config.edge = .top
             config.dismissAutomaticallyAfter = 5
             config.systemImageName = "arrow.triangle.2.circlepath"
             config.action = { [unowned self] toast in
-                toast.dismissToast(animated: true)
-                _ = self.restoreState()
+                toast.isUserInteractionEnabled = false
+                UIView.animateKeyframes(withDuration: 1, delay: 0, options: .repeat) {
+                    UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.5) {
+                        toast.imageView!.transform = CGAffineTransform(rotationAngle: 0.5 * .pi)
+                    }
+                    UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.5) {
+                        // the translation is because the symbol isn't perfectly centered
+                        toast.imageView!.transform = CGAffineTransform(translationX: -0.5, y: 0).rotated(by: .pi)
+                    }
+                }
+                Task {
+                    _ = await self.restoreState()
+                    toast.dismissToast(animated: true)
+                }
             }
             showToast(configuration: config, animated: true)
             UIAccessibility.post(notification: .announcement, argument: "Synced Position Updated")

Tusker/Screens/Timeline/TimelinesPageViewController.swift

@@ -59,7 +59,9 @@ class TimelinesPageViewController: SegmentedPageViewController<TimelinesPageView
                 guard let vc = currentViewController as? TimelineViewController else {
                     return false
                 }
-                _ = vc.restoreState()
+                Task {
+                    _ = await vc.restoreState()
+                }
                 return true
             }),
         ]

Tusker/Views/Toast/ToastView.swift

@@ -12,6 +12,8 @@ class ToastView: UIView {
 
     let configuration: ToastConfiguration
     
+    private(set) var imageView: UIImageView?
+    
     private var panRecognizer: UIPanGestureRecognizer!
     private var shrinkAnimator: UIViewPropertyAnimator?
     private var recognizedGesture = false
@@ -61,6 +63,7 @@ class ToastView: UIView {
             imageView.tintColor = .white
             imageView.contentMode = .scaleAspectFit
             stack.addArrangedSubview(imageView)
+            self.imageView = imageView
         }
         
         let titleLabel = UILabel()