Smoother scrolling up in the Timeline

Packages/Account/Sources/Account/AccountDetailViewModel.swift

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

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

@@ -16,5 +16,5 @@ public protocol StatusesFetcher: ObservableObject {
   var statusesState: StatusesState { get }
   func fetchStatuses() async
   func fetchNextPage() async
-  func statusDidAppear(status: Status) async
+  func statusDidAppear(status: Status)
 }

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

@@ -56,9 +56,7 @@ public struct StatusesListView<Fetcher>: View where Fetcher: StatusesFetcher {
                                  bottom: 12,
                                  trailing: .layoutPadding))
             .onAppear {
-              Task {
+              fetcher.statusDidAppear(status: status)
-                await fetcher.statusDidAppear(status: status)
-              }
             }
           if !isEmbdedInList {
             Divider()

Packages/Timeline/Sources/Timeline/PendingStatusesObserver.swift

@@ -0,0 +1,22 @@
+import Foundation
+import SwiftUI
+import Models
+
+@MainActor
+class PendingStatusesObserver: ObservableObject {
+  @Published var pendingStatusesCount: Int = 0
+  
+  var pendingStatuses: [String] = [] {
+    didSet {
+      pendingStatusesCount = pendingStatuses.count
+    }
+  }
+  
+  func removeStatus(status: Status) {
+    if let index = pendingStatuses.firstIndex(of: status.id) {
+      pendingStatuses.removeSubrange(index...(pendingStatuses.count - 1))
+    }
+  }
+  
+  init() { }
+}

Packages/Timeline/Sources/Timeline/TimelineView.swift

@@ -19,8 +19,10 @@ public struct TimelineView: View {
   @EnvironmentObject private var routerPath: RouterPath
 
   @StateObject private var viewModel = TimelineViewModel()
+  @StateObject private var pendingStatusesObserver = PendingStatusesObserver()
 
   @State private var scrollProxy: ScrollViewProxy?
+  
   @Binding var timeline: TimelineFilter
   @Binding var scrollToTopSignal: Int
 
@@ -62,9 +64,14 @@ public struct TimelineView: View {
     .navigationTitle(timeline.localizedTitle())
     .navigationBarTitleDisplayMode(.inline)
     .onAppear {
+      viewModel.pendingStatusesObserver = pendingStatusesObserver
       if viewModel.client == nil {
         viewModel.client = client
         viewModel.timeline = timeline
+      } else {
+        Task {
+          await viewModel.fetchStatuses(userIntent: false)
+        }
       }
     }
     .refreshable {
@@ -105,15 +112,15 @@ public struct TimelineView: View {
 
   @ViewBuilder
   private func makePendingNewPostsView(proxy: ScrollViewProxy) -> some View {
-    if !viewModel.pendingStatuses.isEmpty {
+    if pendingStatusesObserver.pendingStatusesCount > 0 {
       HStack(spacing: 6) {
         Spacer()
         Button {
           withAnimation {
-            proxy.scrollTo(viewModel.pendingStatuses.last?.id, anchor: .bottom)
+            proxy.scrollTo(pendingStatusesObserver.pendingStatuses.last, anchor: .bottom)
           }
         } label: {
-          Text(viewModel.pendingStatusesButtonTitle)
+          Text("\(pendingStatusesObserver.pendingStatusesCount)")
         }
         .buttonStyle(.bordered)
         .background(.thinMaterial)

Packages/Timeline/Sources/Timeline/TimelineViewModel.swift

@@ -17,13 +17,15 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
   // Internal source of truth for a timeline.
   private var statuses: [Status] = []
   
+  var pendingStatusesObserver: PendingStatusesObserver?
+
   @Published var statusesState: StatusesState = .loading
   @Published var timeline: TimelineFilter = .federated {
     didSet {
       Task {
         if oldValue != timeline {
           statuses = []
-          pendingStatuses = []
+          pendingStatusesObserver?.pendingStatuses = []
           tag = nil
         }
         await fetchStatuses(userIntent: false)
@@ -38,11 +40,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
   }
 
   @Published var tag: Tag?
-  @Published var pendingStatuses: [Status] = []
+  @Published var pendingStatusesCount: Int = 0
-
-  var pendingStatusesButtonTitle: LocalizedStringKey {
-    "\(pendingStatuses.count)"
-  }
 
   var pendingStatusesEnabled: Bool {
     timeline == .home
@@ -60,7 +58,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
     guard let client else { return }
     do {
       if statuses.isEmpty {
-        pendingStatuses = []
+        pendingStatusesObserver?.pendingStatuses = []
         statusesState = .loading
         statuses = try await client.get(endpoint: timeline.endpoint(sinceId: nil,
                                                                     maxId: nil,
@@ -69,11 +67,11 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
         withAnimation {
           statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
         }
-      } else if let first = pendingStatuses.first ?? statuses.first {
+      } else if let first = statuses.first {
         var newStatuses: [Status] = await fetchNewPages(minId: first.id, maxPages: 20)
         if userIntent || !pendingStatusesEnabled {
-          statuses.insert(contentsOf: pendingStatuses, at: 0)
+          statuses.insert(contentsOf: newStatuses, at: 0)
-          pendingStatuses = []
+          pendingStatusesObserver?.pendingStatuses = []
           withAnimation {
             statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
           }
@@ -81,7 +79,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
           newStatuses = newStatuses.filter { status in
             !statuses.contains(where: { $0.id == status.id })
           }
-          pendingStatuses.insert(contentsOf: newStatuses, at: 0)
+          pendingStatusesObserver?.pendingStatuses.insert(contentsOf: newStatuses.map{ $0.id }, at: 0)
           statuses.insert(contentsOf: newStatuses, at: 0)
           withAnimation {
             statusesState = .display(statuses: statuses, nextPageState: statuses.count < 20 ? .none : .hasNextPage)
@@ -145,7 +143,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
        pendingStatusesEnabled,
        !statuses.contains(where: { $0.id == event.status.id })
     {
-      pendingStatuses.insert(event.status, at: 0)
+      pendingStatusesObserver?.pendingStatuses.insert(event.status.id, at: 0)
       statuses.insert(event.status, at: 0)
       withAnimation {
         statusesState = .display(statuses: statuses, nextPageState: .hasNextPage)
@@ -163,9 +161,7 @@ class TimelineViewModel: ObservableObject, StatusesFetcher {
     }
   }
 
-  func statusDidAppear(status: Status) async {
+  func statusDidAppear(status: Status) {
-    if let index = pendingStatuses.firstIndex(of: status) {
+    pendingStatusesObserver?.removeStatus(status: status)
-      pendingStatuses.remove(at: index)
-    }
   }
 }