Restore ScrollToTop on timeline tab

IceCubesApp/App/Main/AppView.swift

@@ -26,6 +26,7 @@ struct AppView: View {
 
   @State var iosTabs = iOSTabs.shared
   @State var sidebarTabs = SidebarTabs.shared
+  @State var selectedTabScrollToTop: Int = -1
 
   var body: some View {
     #if os(visionOS)
@@ -75,6 +76,7 @@ struct AppView: View {
     }
     .id(appAccountsManager.currentClient.id)
     .withSheetDestinations(sheetDestinations: $appRouterPath.presentedSheet)
+    .environment(\.selectedTabScrollToTop, selectedTabScrollToTop)
   }
   
   private func updateTab(with newTab: AppTab) {
@@ -90,6 +92,15 @@ struct AppView: View {
     HapticManager.shared.fireHaptic(.tabSelection)
     SoundEffectManager.shared.playSound(.tabSelection)
 
+    if selectedTab == newTab {
+      selectedTabScrollToTop = newTab.rawValue
+      DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+        selectedTabScrollToTop = -1
+      }
+    } else {
+      selectedTabScrollToTop = -1
+    }
+    
     selectedTab = newTab
   }
 

Packages/Env/Sources/Env/CustomEnvValues.swift

@@ -12,4 +12,5 @@ extension EnvironmentValues {
   @Entry public var isStatusFocused: Bool = false
   @Entry public var isHomeTimeline: Bool = false
   @Entry public var indentationLevel: UInt = 0
+  @Entry public var selectedTabScrollToTop: Int = -1
 }

Packages/Timeline/Sources/Timeline/View/TimelineView.swift

@@ -11,6 +11,8 @@ import SwiftUIIntrospect
 @MainActor
 public struct TimelineView: View {
   @Environment(\.scenePhase) private var scenePhase
+  @Environment(\.selectedTabScrollToTop) private var selectedTabScrollToTop
+  
   @Environment(Theme.self) private var theme
   @Environment(CurrentAccount.self) private var account
   @Environment(StreamWatcher.self) private var watcher
@@ -45,6 +47,7 @@ public struct TimelineView: View {
 
   public var body: some View {
     ZStack(alignment: .top) {
+      ScrollViewReader { proxy in
         List {
           scrollToTopView
           TimelineTagGroupheaderView(group: $selectedTagGroup, timeline: $timeline)
@@ -60,6 +63,13 @@ public struct TimelineView: View {
         .id(client.id)
         .environment(\.defaultMinListRowHeight, 1)
         .listStyle(.plain)
+        .onChange(of: selectedTabScrollToTop) { _, newValue in
+          if newValue == 0, routerPath.path.isEmpty {
+            withAnimation {
+              proxy.scrollTo(ScrollToView.Constants.scrollToTop, anchor: .top)
+            }
+          }
+        }
         #if !os(visionOS)
           .scrollContentBackground(.hidden)
           .background(theme.primaryBackgroundColor)
@@ -72,6 +82,7 @@ public struct TimelineView: View {
             collectionView.isPrefetchingEnabled = true
             collectionView.prefetchDataSource = prefetcher
           }
+      }
       if viewModel.timeline.supportNewestPagination {
         TimelineUnreadStatusesView(observer: viewModel.pendingStatusesObserver)
       }