Iron out timeline issues with the new behaviour

Packages/Account/Sources/Account/AccountDetailViewModel.swift

@@ -247,7 +247,7 @@ class AccountDetailViewModel: ObservableObject, StatusesFetcher {
     }
   }
   
-  func statusDidAppear(status: Models.Status)  {
+  func statusDidAppear(status: Models.Status) { }
-    
+  
-  }
+  func statusDidDisappear(status: Status) { }
 }

Packages/Status/Sources/Status/List/StatusesFetcher.swift

@@ -17,4 +17,5 @@ public protocol StatusesFetcher: ObservableObject {
   func fetchStatuses() async
   func fetchNextPage() async
   func statusDidAppear(status: Status)
+  func statusDidDisappear(status: Status)
 }

Packages/Status/Sources/Status/List/StatusesListView.swift

@@ -59,6 +59,9 @@ public struct StatusesListView<Fetcher>: View where Fetcher: StatusesFetcher {
             .onAppear {
               fetcher.statusDidAppear(status: status)
             }
+            .onDisappear {
+              fetcher.statusDidDisappear(status: status)
+            }
           if !isEmbdedInList {
             Divider()
               .padding(.vertical, .dividerPadding)

Packages/Status/Sources/Status/Row/StatusMediaPreviewView.swift

@@ -199,6 +199,7 @@ public struct StatusMediaPreviewView: View {
             Text("status.image.alt-text.abbreviation")
               .font(theme.statusDisplayStyle == .compact ? .footnote : .body)
           }
+          .buttonStyle(.borderless)
           .padding(4)
           .background(.thinMaterial)
           .cornerRadius(4)
@@ -242,6 +243,7 @@ public struct StatusMediaPreviewView: View {
                   Text("status.image.alt-text.abbreviation")
                     .font(.scaledFootnote)
                 }
+                .buttonStyle(.borderless)
                 .padding(4)
                 .background(.thinMaterial)
                 .cornerRadius(4)
@@ -287,6 +289,7 @@ public struct StatusMediaPreviewView: View {
   private var sensitiveMediaOverlay: some View {
     ZStack {
       Rectangle()
+        .foregroundColor(.clear)
         .background(.ultraThinMaterial)
       if !isNotifications {
         Button {
@@ -294,11 +297,14 @@ public struct StatusMediaPreviewView: View {
             isHidingMedia = false
           }
         } label: {
-          if sensitive {
+          Group {
-            Label("status.media.sensitive.show", systemImage: "eye")
+            if sensitive {
-          } else {
+              Label("status.media.sensitive.show", systemImage: "eye")
-            Label("status.media.content.show", systemImage: "eye")
+            } else {
+              Label("status.media.content.show", systemImage: "eye")
+            }
           }
+          .foregroundColor(theme.labelColor)
         }
         .buttonStyle(.borderedProminent)
       }

Packages/Timeline/Sources/Timeline/PendingStatusesObserver.swift

@@ -4,8 +4,12 @@ import Models
 
 @MainActor
 class PendingStatusesObserver: ObservableObject {
+  let feedbackGenerator = UIImpactFeedbackGenerator(style: .light)
+  
   @Published var pendingStatusesCount: Int = 0
   
+  var disableUpdate: Bool = false
+  
   var pendingStatuses: [String] = [] {
     didSet {
       pendingStatusesCount = pendingStatuses.count
@@ -13,8 +17,9 @@ class PendingStatusesObserver: ObservableObject {
   }
   
   func removeStatus(status: Status) {
-    if let index = pendingStatuses.firstIndex(of: status.id) {
+    if !disableUpdate, let index = pendingStatuses.firstIndex(of: status.id) {
       pendingStatuses.removeSubrange(index...(pendingStatuses.count - 1))
+      feedbackGenerator.impactOccurred()
     }
   }
   

Packages/Timeline/Sources/Timeline/TimelineView.swift

@@ -20,7 +20,6 @@ public struct TimelineView: View {
 
   @StateObject private var viewModel = TimelineViewModel()
   
-  @State private var scrollProxy: ScrollViewProxy?
   @State private var wasBackgrounded: Bool = false
   
   @Binding var timeline: TimelineFilter
@@ -58,7 +57,7 @@ public struct TimelineView: View {
         }
       }
       .onAppear {
-        scrollProxy = proxy
+        viewModel.scrollProxy = proxy
       }
     }
     .navigationTitle(timeline.localizedTitle())
@@ -85,7 +84,7 @@ public struct TimelineView: View {
     }
     .onChange(of: scrollToTopSignal, perform: { _ in
       withAnimation {
-        scrollProxy?.scrollTo(Constants.scrollToTop, anchor: .top)
+        viewModel.scrollProxy?.scrollTo(Constants.scrollToTop, anchor: .top)
       }
     })
     .onChange(of: timeline) { newTimeline in

Packages/Timeline/Sources/Timeline/TimelineViewModel.swift

@@ -16,6 +16,10 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
 
   // Internal source of truth for a timeline.
   private var statuses: [Status] = []
+  private var visibileStatusesIds = Set<String>()
+  private var isFetchingNewPages: Bool = false
+  
+  var scrollProxy: ScrollViewProxy?
   
   var pendingStatusesObserver: PendingStatusesObserver = .init()
 
@@ -55,7 +59,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
   }
 
   func fetchStatuses(userIntent: Bool) async {
-    guard let client else { return }
+    guard let client, !isFetchingNewPages else { return }
     do {
       if statuses.isEmpty {
         pendingStatusesObserver.pendingStatuses = []
@@ -68,6 +72,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
           statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
         }
       } else if let first = statuses.first {
+        isFetchingNewPages = true
         var newStatuses: [Status] = await fetchNewPages(minId: first.id, maxPages: 20)
         if userIntent || !pendingStatusesEnabled {
           statuses.insert(contentsOf: newStatuses, at: 0)
@@ -80,14 +85,31 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
             !statuses.contains(where: { $0.id == status.id })
           }
           pendingStatusesObserver.pendingStatuses.insert(contentsOf: newStatuses.map{ $0.id }, at: 0)
-          statuses.insert(contentsOf: newStatuses, at: 0)
+          pendingStatusesObserver.feedbackGenerator.impactOccurred()
-          withAnimation {
+          
-            statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
+          // High chance the user is scrolled to the top, this is a workaround to keep scroll position when prepending statuses.
+          if let firstStatusId = statuses.first?.id, visibileStatusesIds.contains(firstStatusId) {
+            statuses.insert(contentsOf: newStatuses, at: 0)
+            pendingStatusesObserver.disableUpdate = true
+            withAnimation {
+              statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
+              DispatchQueue.main.async {
+                self.scrollProxy?.scrollTo(firstStatusId)
+                self.pendingStatusesObserver.disableUpdate = false
+              }
+            }
+          } else {
+            statuses.insert(contentsOf: newStatuses, at: 0)
+            withAnimation {
+              statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
+            }
           }
         }
+        isFetchingNewPages = false
       }
     } catch {
       statusesState = .error(error: error)
+      isFetchingNewPages = false
       print("timeline parse error: \(error)")
     }
   }
@@ -141,6 +163,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
   func handleEvent(event: any StreamEvent, currentAccount: CurrentAccount) {
     if let event = event as? StreamEventUpdate,
        pendingStatusesEnabled,
+       !isFetchingNewPages,
        !statuses.contains(where: { $0.id == event.status.id })
     {
       pendingStatusesObserver.pendingStatuses.insert(event.status.id, at: 0)
@@ -163,5 +186,10 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
 
   func statusDidAppear(status: Status) {
     pendingStatusesObserver.removeStatus(status: status)
+    visibileStatusesIds.insert(status.id)
+  }
+  
+  func statusDidDisappear(status: Status) {
+    visibileStatusesIds.remove(status.id)
   }
 }