feat(App): Implement Haptic Feedback for Tab switches and Timeline reload

Mastodon/Scene/HomeTimeline/HomeTimelineViewController.swift

@@ -394,7 +394,7 @@ extension HomeTimelineViewController {
     }
 
     @objc private func refreshControlValueChanged(_ sender: RefreshControl) {
-        guard viewModel.loadLatestStateMachine.enter(HomeTimelineViewModel.LoadLatestState.Loading.self) else {
+        guard viewModel.loadLatestStateMachine.enter(HomeTimelineViewModel.LoadLatestState.LoadingManually.self) else {
             sender.endRefreshing()
             return
         }

Mastodon/Scene/HomeTimeline/HomeTimelineViewModel+LoadLatestState.swift

@@ -61,7 +61,35 @@ extension HomeTimelineViewModel.LoadLatestState {
         }
         
         override func didEnter(from previousState: GKState?) {
+            didEnter(from: previousState, viewModel: viewModel, isUserInitiated: false)
+        }
+    }
+    
+    class LoadingManually: HomeTimelineViewModel.LoadLatestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Fail.self || stateClass == Idle.self
+        }
+        
+        override func didEnter(from previousState: GKState?) {
+            didEnter(from: previousState, viewModel: viewModel, isUserInitiated: true)
+        }
+    }
+    
+    class Fail: HomeTimelineViewModel.LoadLatestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Loading.self || stateClass == Idle.self
+        }
+    }
+    
+    class Idle: HomeTimelineViewModel.LoadLatestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Loading.self
+        }
+    }
+
+    private func didEnter(from previousState: GKState?, viewModel: HomeTimelineViewModel?, isUserInitiated: Bool) {
         super.didEnter(from: previousState)
+
         guard let viewModel else { return }
         
         let latestFeedRecords = viewModel.fetchedResultsController.records.prefix(APIService.onceRequestStatusMaxCount)
@@ -102,6 +130,11 @@ extension HomeTimelineViewModel.LoadLatestState {
                 }
                 viewModel.timelineIsEmpty.value = latestStatusIDs.isEmpty && statuses.isEmpty
                 
+                if !isUserInitiated {
+                    await UIImpactFeedbackGenerator(style: .light)
+                        .impactOccurred()
+                }
+                
             } catch {
                 logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public): fetch statuses failed: \(error.localizedDescription)")
                 await enter(state: Idle.self)
@@ -111,17 +144,3 @@ extension HomeTimelineViewModel.LoadLatestState {
         }   // end Task
     }
 }
-    
-    class Fail: HomeTimelineViewModel.LoadLatestState {
-        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
-            return stateClass == Loading.self || stateClass == Idle.self
-        }
-    }
-    
-    class Idle: HomeTimelineViewModel.LoadLatestState {
-        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
-            return stateClass == Loading.self
-        }
-    }
-
-}

Mastodon/Scene/HomeTimeline/HomeTimelineViewModel.swift

@@ -52,6 +52,7 @@ final class HomeTimelineViewModel: NSObject {
         let stateMachine = GKStateMachine(states: [
             LoadLatestState.Initial(viewModel: self),
             LoadLatestState.Loading(viewModel: self),
+            LoadLatestState.LoadingManually(viewModel: self),
             LoadLatestState.Fail(viewModel: self),
             LoadLatestState.Idle(viewModel: self),
         ])

Mastodon/Scene/Root/MainTab/MainTabBarController.swift

@@ -155,6 +155,9 @@ class MainTabBarController: UITabBarController {
     var avatarURLObserver: AnyCancellable?
     @Published var avatarURL: URL?
     
+    // haptic feedback
+    private let selectionFeedbackGenerator = UIImpactFeedbackGenerator(style: .medium)
+    
     init(
         context: AppContext,
         coordinator: SceneCoordinator,
@@ -378,6 +381,7 @@ extension MainTabBarController {
     
     @objc private func composeButtonDidPressed(_ sender: Any) {
         logger.log(level: .debug, "\((#file as NSString).lastPathComponent, privacy: .public)[\(#line, privacy: .public)], \(#function, privacy: .public)")
+        selectionFeedbackGenerator.impactOccurred()
         guard let authContext = self.authContext else { return }
         let composeViewModel = ComposeViewModel(
             context: context,
@@ -573,6 +577,11 @@ extension MainTabBarController: UITabBarControllerDelegate {
             return false
         }
         
+        // Different tab has been selected, send haptic feedback
+        if viewController.tabBarItem.tag != tabBarController.selectedIndex {
+            selectionFeedbackGenerator.impactOccurred()
+        }
+
         // Assert index is as same as the tab rawValue. This check needs to be done `shouldSelect`
         // because the nav controller has already popped in `didSelect`.
         if currentTab.rawValue == tabBarController.selectedIndex,