fix: add animation transition to chat message on mobile

RxCodeMobile/State/MobileAppState+Inbound.swift

@@ -106,6 +106,7 @@ extension MobileAppState {
                 } else if messagesBySession[active] == nil {
                     messagesBySession[active] = []
                 }
+                loadingThreadMessageSessions.remove(active)
                 activeSessionID = active
             }
             hasReceivedInitialSnapshot = true
@@ -362,6 +363,9 @@ extension MobileAppState {
             if loadingMoreSessions.remove(previous) != nil {
                 loadingMoreSessions.insert(update.sessionID)
             }
+            if loadingThreadMessageSessions.remove(previous) != nil {
+                loadingThreadMessageSessions.insert(update.sessionID)
+            }
             if activeSessionID == previous {
                 activeSessionID = update.sessionID
             }

RxCodeMobile/State/MobileAppState+Intents.swift

@@ -47,6 +47,12 @@ extension MobileAppState {
         loadingMoreSessions.contains(sessionID)
     }
 
+    /// Whether the initial message window for a newly opened thread is still
+    /// being refreshed from the desktop.
+    func isLoadingThreadMessages(sessionID: String) -> Bool {
+        loadingThreadMessageSessions.contains(sessionID)
+    }
+
     /// Mirror of the desktop's per-session queue, surfaced via `SessionSummary`.
     func queuedMessages(sessionID: String) -> [QueuedUserMessage] {
         sessions.first(where: { $0.id == sessionID })?.queuedMessages ?? []
@@ -187,6 +193,7 @@ extension MobileAppState {
     /// Archive a thread. Optimistically flips `isArchived` so the row drops out
     /// of the active list right away.
     func archiveThread(sessionID: String) async {
+        loadingThreadMessageSessions.remove(sessionID)
         replaceSession(sessionID: sessionID) { current in
             SessionSummary(
                 id: current.id,
@@ -210,6 +217,7 @@ extension MobileAppState {
         messagesBySession.removeValue(forKey: sessionID)
         sessionsWithMoreMessages.remove(sessionID)
         loadingMoreSessions.remove(sessionID)
+        loadingThreadMessageSessions.remove(sessionID)
         if activeSessionID == sessionID { activeSessionID = nil }
         await sendThreadAction(sessionID: sessionID, action: .delete)
     }
@@ -276,7 +284,18 @@ extension MobileAppState {
     func subscribe(to sessionID: String?) async {
         activeSessionID = sessionID
         guard isPaired else { return }
+        if let sessionID {
+            loadingThreadMessageSessions = [sessionID]
+        } else {
+            loadingThreadMessageSessions.removeAll()
+        }
         let payload = SubscribeSessionPayload(sessionID: sessionID)
-        try? await client.send(.subscribeSession(payload), toHex: pairedDesktopPubkey)
+        do {
+            try await client.send(.subscribeSession(payload), toHex: pairedDesktopPubkey)
+        } catch {
+            if let sessionID {
+                loadingThreadMessageSessions.remove(sessionID)
+            }
+        }
     }
 }

RxCodeMobile/State/MobileAppState.swift

@@ -152,6 +152,9 @@ final class MobileAppState: ObservableObject {
     @Published var sessionsWithMoreMessages: Set<String> = []
     /// Sessions with an in-flight `load_more_messages` request.
     @Published var loadingMoreSessions: Set<String> = []
+    /// Sessions whose initial message page is being refreshed after opening the
+    /// chat detail view.
+    @Published var loadingThreadMessageSessions: Set<String> = []
     /// Maps an outstanding load-more request ID to its session, so a late
     /// `more_messages` reply lands on the right thread.
     var pendingLoadMoreRequests: [UUID: String] = [:]

RxCodeMobile/Views/MobileBriefingView.swift

@@ -26,6 +26,7 @@ struct GroupedBriefing: Identifiable {
 struct MobileBriefingView: View {
     @EnvironmentObject private var state: MobileAppState
     @Namespace private var glassNamespace
+    var onCloseChat: () -> Void = {}
 
     /// Selected project ids for filtering. Empty = show every project.
     @State private var selectedProjectIds: Set<UUID> = []
@@ -84,8 +85,9 @@ struct MobileBriefingView: View {
             MobileBriefingDetailView(groupKey: key)
         }
         .navigationDestination(for: String.self) { sessionID in
-            MobileChatView(sessionID: sessionID)
+            MobileChatView(sessionID: sessionID, onClose: onCloseChat)
                 .id(sessionID)
+                .toolbar(.hidden, for: .tabBar)
                 .task(id: sessionID) {
                     if !MobileDraftSessionID.isDraft(sessionID) {
                         await state.subscribe(to: sessionID)

RxCodeMobile/Views/MobileChatView.swift

@@ -63,6 +63,7 @@ struct MobileChatView: View {
     /// and should be pinned to the top of the viewport.
     @State private var awaitingSentUserMessage = false
     @State private var distanceFromBottom: CGFloat = 0
+    @State private var minimumThreadLoadElapsed = false
 
     private static let bottomAnchorID = "message-list-bottom"
     /// Distance from the bottom past which the "scroll to bottom" button shows.
@@ -83,9 +84,13 @@ struct MobileChatView: View {
             .animation(.easeInOut(duration: 0.2), value: queuedMessages.count)
             .animation(.easeInOut(duration: 0.2), value: sessionQuestions.count)
             .animation(.easeInOut(duration: 0.2), value: pendingPlans.count)
+            .animation(.easeInOut(duration: 0.25), value: shouldShowThreadLoading)
             .navigationBarTitleDisplayMode(.inline)
             .navigationTitle(title)
             .toolbar { threadActionsToolbar }
+            .task(id: sessionID) {
+                await runThreadLoadingGate()
+            }
             .sheet(isPresented: $showingQueueSheet) {
                 QueuedMessagesSheet(
                     messages: queuedMessages,
@@ -488,6 +493,17 @@ struct MobileChatView: View {
             } action: { newValue in
                 composerMinY = newValue
             }
+
+            if shouldShowThreadLoading {
+                MobileThreadLoadingOverlay()
+                    .transition(
+                        .asymmetric(
+                            insertion: .opacity.combined(with: .scale(scale: 0.98)),
+                            removal: .opacity.combined(with: .move(edge: .bottom))
+                        )
+                    )
+                    .zIndex(3)
+            }
         }
     }
 
@@ -540,6 +556,11 @@ struct MobileChatView: View {
         state.isLoadingMoreMessages(sessionID: sessionID)
     }
 
+    private var shouldShowThreadLoading: Bool {
+        !MobileDraftSessionID.isDraft(sessionID)
+            && (!minimumThreadLoadElapsed || state.isLoadingThreadMessages(sessionID: sessionID))
+    }
+
     private var queuedMessages: [QueuedUserMessage] {
         state.queuedMessages(sessionID: sessionID)
     }
@@ -560,6 +581,21 @@ struct MobileChatView: View {
         sessionPlans.filter { !$0.isDecided && !$0.isStreaming }
     }
 
+    // MARK: - Initial loading
+
+    private func runThreadLoadingGate() async {
+        minimumThreadLoadElapsed = false
+        do {
+            try await Task.sleep(for: .seconds(1))
+        } catch {
+            return
+        }
+        guard !Task.isCancelled else { return }
+        withAnimation(.easeInOut(duration: 0.25)) {
+            minimumThreadLoadElapsed = true
+        }
+    }
+
     // MARK: - Message paging
 
     /// Spinner shown at the top of the list while an older page is loading.