Reconfigure visible updates when refreshing

Closes #300

Tusker/Screens/Notifications/NotificationsCollectionViewController.swift

@@ -25,6 +25,8 @@ class NotificationsCollectionViewController: UIViewController, TimelineLikeColle
     private(set) var collectionView: UICollectionView!
     private(set) var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
     
+    var reconfigureVisibleItemsOnEndDecelerating: Bool = false
+    
     private var newer: RequestRange?
     private var older: RequestRange?
     
@@ -662,6 +664,13 @@ extension NotificationsCollectionViewController: UICollectionViewDelegate {
     func collectionView(_ collectionView: UICollectionView, willPerformPreviewActionForMenuWith configuration: UIContextMenuConfiguration, animator: UIContextMenuInteractionCommitAnimating) {
         MenuPreviewHelper.willPerformPreviewAction(animator: animator, presenter: self)
     }
+    
+    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+        if reconfigureVisibleItemsOnEndDecelerating {
+            reconfigureVisibleItemsOnEndDecelerating = false
+            reconfigureVisibleCells()
+        }
+    }
 }
 
 extension NotificationsCollectionViewController: UICollectionViewDragDelegate {

Tusker/Screens/Profile/ProfileStatusesViewController.swift

@@ -32,6 +32,8 @@ class ProfileStatusesViewController: UIViewController, TimelineLikeCollectionVie
     private(set) var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
     private(set) var headerCell: ProfileHeaderCollectionViewCell?
     
+    var reconfigureVisibleItemsOnEndDecelerating: Bool = false
+    
     private(set) var state: State = .unloaded
     
     init(accountID: String?, kind: Kind, owner: ProfileViewController) {
@@ -627,6 +629,13 @@ extension ProfileStatusesViewController: UICollectionViewDelegate {
             return true
         }
     }
+    
+    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+        if reconfigureVisibleItemsOnEndDecelerating {
+            reconfigureVisibleItemsOnEndDecelerating = false
+            reconfigureVisibleCells()
+        }
+    }
 }
 
 extension ProfileStatusesViewController: UICollectionViewDragDelegate {

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -42,6 +42,8 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
     private(set) var collectionView: UICollectionView!
     private(set) var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
     
+    var reconfigureVisibleItemsOnEndDecelerating: Bool = false
+    
     private var cancellables = Set<AnyCancellable>()
     private var userActivityNeedsUpdate = PassthroughSubject<Void, Never>()
     // the last time this VC disappeared or the scene was backgrounded while it was active, used to decide if we want to check for present when reappearing
@@ -1317,6 +1319,11 @@ extension TimelineViewController: UICollectionViewDelegate {
     
     func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
         userActivityNeedsUpdate.send()
+        
+        if reconfigureVisibleItemsOnEndDecelerating {
+            reconfigureVisibleItemsOnEndDecelerating = false
+            reconfigureVisibleCells()
+        }
     }
     
     func scrollViewDidScroll(_ scrollView: UIScrollView) {

Tusker/Screens/Utilities/TimelineLikeCollectionViewController.swift

@@ -21,6 +21,8 @@ protocol TimelineLikeCollectionViewController: UIViewController, TimelineLikeCon
     
     var collectionView: UICollectionView! { get }
     var dataSource: UICollectionViewDiffableDataSource<Section, Item>! { get }
+    
+    var reconfigureVisibleItemsOnEndDecelerating: Bool { get set }
 }
 
 protocol TimelineLikeCollectionViewSection: Hashable, Sendable {
@@ -125,6 +127,18 @@ extension TimelineLikeCollectionViewController {
         var config: ToastConfiguration
         if let error = error as? Self.Error,
            error == .allCaughtUp {
+            // Reconfigure visible items to update timestamps.
+            #if targetEnvironment(macCatalyst)
+            let isRefreshing = false
+            #else
+            let isRefreshing = collectionView.refreshControl?.isRefreshing ?? false
+            #endif
+            if isRefreshing {
+                reconfigureVisibleItemsOnEndDecelerating = true
+            } else {
+                reconfigureVisibleCells()
+            }
+            
             config = ToastConfiguration(title: "You're all caught up")
             config.edge = .top
             config.dismissAutomaticallyAfter = 2
@@ -204,6 +218,16 @@ extension TimelineLikeCollectionViewController {
         await task.value
     }
     
+    @MainActor
+    func reconfigureVisibleCells() {
+        let items = collectionView.indexPathsForVisibleItems.compactMap { dataSource.itemIdentifier(for: $0) }
+        if !items.isEmpty {
+            var snapshot = dataSource.snapshot()
+            snapshot.reconfigureItems(items)
+            dataSource.apply(snapshot, animatingDifferences: false)
+        }
+    }
+    
     func registerTimelineLikeCells() {
         collectionView.register(LoadingCollectionViewCell.self, forCellWithReuseIdentifier: "loadingIndicator")
         collectionView.register(ConfirmLoadMoreCollectionViewCell.self, forCellWithReuseIdentifier: "confirmLoadMore")