added the avatar and the room title as subtitle in the thread timeline as a principal action

also added a fix for the erroneous reply in thread action while in a thread, and also discovered that we can lead align the principal action again on iOS 26 (so it was a beta issue)

ElementX/Sources/Other/SwiftUI/Views/RoomHeaderView.swift

@@ -11,17 +11,14 @@ import SwiftUI
 
 struct RoomHeaderView: View {
     let roomName: String
+    var roomSubtitle: String?
     let roomAvatar: RoomAvatar
     var dmRecipientVerificationState: UserIdentityVerificationState?
     
     let mediaProvider: MediaProviderProtocol?
     
     var body: some View {
-        if #available(iOS 19, *) {
-            // https://github.com/element-hq/element-x-ios/issues/4180
-            // Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSLayoutConstraint constant is not finite!
-            content
-        } else if ProcessInfo.isRunningAccessibilityTests {
+        if ProcessInfo.isRunningAccessibilityTests {
             // Accessibility tests scale up the dynamic size in real time which may break the view
             content
         } else {
@@ -37,10 +34,18 @@ struct RoomHeaderView: View {
                 .accessibilityHidden(true)
             
             HStack(spacing: 4) {
-                Text(roomName)
-                    .lineLimit(1)
-                    .font(.compound.bodyLGSemibold)
-                    .accessibilityIdentifier(A11yIdentifiers.roomScreen.name)
+                VStack(alignment: .leading, spacing: 0) {
+                    Text(roomName)
+                        .lineLimit(1)
+                        .font(.compound.bodyLGSemibold)
+                        .accessibilityIdentifier(A11yIdentifiers.roomScreen.name)
+                    if let roomSubtitle {
+                        Text(roomSubtitle)
+                            .lineLimit(1)
+                            .font(.compound.bodyXS)
+                            .foregroundStyle(.compound.textSecondary)
+                    }
+                }
                 
                 if let dmRecipientVerificationState {
                     VerificationBadge(verificationState: dmRecipientVerificationState)

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenCoordinator.swift

@@ -54,7 +54,7 @@ final class ThreadTimelineScreenCoordinator: CoordinatorProtocol {
     init(parameters: ThreadTimelineScreenCoordinatorParameters) {
         self.parameters = parameters
         
-        viewModel = ThreadTimelineScreenViewModel(roomProxy: parameters.roomProxy)
+        viewModel = ThreadTimelineScreenViewModel(roomProxy: parameters.roomProxy, userSession: parameters.userSession)
         
         timelineViewModel = TimelineViewModel(roomProxy: parameters.roomProxy,
                                               timelineController: parameters.timelineController,

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenModels.swift

@@ -10,7 +10,10 @@ import Foundation
 enum ThreadTimelineScreenViewModelAction { }
 
 struct ThreadTimelineScreenViewState: BindableState {
+    var roomTitle: String
+    var roomAvatar: RoomAvatar
     var canSendMessage = true
+    var dmRecipientVerificationState: UserIdentityVerificationState?
     
     var bindings = ThreadTimelineScreenViewStateBindings()
 }

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenViewModel.swift

@@ -12,16 +12,20 @@ typealias ThreadTimelineScreenViewModelType = StateStoreViewModel<ThreadTimeline
 
 class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTimelineScreenViewModelProtocol {
     private let roomProxy: JoinedRoomProxyProtocol
+    private let userSession: UserSessionProtocol
     
     private let actionsSubject: PassthroughSubject<ThreadTimelineScreenViewModelAction, Never> = .init()
     var actionsPublisher: AnyPublisher<ThreadTimelineScreenViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
     }
     
-    init(roomProxy: JoinedRoomProxyProtocol) {
+    init(roomProxy: JoinedRoomProxyProtocol,
+         userSession: UserSessionProtocol) {
         self.roomProxy = roomProxy
+        self.userSession = userSession
         
-        super.init(initialViewState: ThreadTimelineScreenViewState())
+        super.init(initialViewState: ThreadTimelineScreenViewState(roomTitle: roomProxy.infoPublisher.value.displayName ?? roomProxy.id,
+                                                                   roomAvatar: roomProxy.infoPublisher.value.avatar), mediaProvider: userSession.mediaProvider)
         
         roomProxy.infoPublisher
             .receive(on: DispatchQueue.main)
@@ -30,7 +34,20 @@ class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTi
             }
             .store(in: &cancellables)
         
+        let identityStatusChangesPublisher = roomProxy.identityStatusChangesPublisher.receive(on: DispatchQueue.main)
+        Task { [weak self] in
+            for await _ in identityStatusChangesPublisher.values {
+                guard !Task.isCancelled else {
+                    return
+                }
+                
+                await self?.updateVerificationBadge()
+            }
+        }
+        .store(in: &cancellables)
+        
         updateRoomInfo(roomProxy.infoPublisher.value)
+        Task { await updateVerificationBadge() }
     }
     
     // MARK: - Public
@@ -58,7 +75,26 @@ class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTi
     
     // MARK: - Private
     
+    private func updateVerificationBadge() async {
+        guard roomProxy.isDirectOneToOneRoom,
+              let dmRecipient = roomProxy.membersPublisher.value.first(where: { $0.userID != roomProxy.ownUserID }),
+              case let .success(userIdentity) = await userSession.clientProxy.userIdentity(for: dmRecipient.userID) else {
+            state.dmRecipientVerificationState = .notVerified
+            return
+        }
+        
+        guard let userIdentity else {
+            MXLog.failure("User identity should be known at this point")
+            state.dmRecipientVerificationState = .notVerified
+            return
+        }
+        
+        state.dmRecipientVerificationState = userIdentity.verificationState
+    }
+    
     private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
+        state.roomTitle = roomInfo.displayName ?? roomProxy.id
+        state.roomAvatar = roomInfo.avatar
         if let powerLevels = roomInfo.powerLevels {
             state.canSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
         }

ElementX/Sources/Screens/ThreadTimelineScreen/View/ThreadTimelineScreen.swift

@@ -23,8 +23,9 @@ struct ThreadTimelineScreen: View {
         
     var body: some View {
         TimelineView(timelineContext: timelineContext)
-            .navigationTitle("Thread")
+            .navigationTitle(L10n.commonThread)
             .navigationBarTitleDisplayMode(.inline)
+            .toolbar { toolbar }
             .background(.compound.bgCanvasDefault)
             .toolbarBackground(.visible, for: .navigationBar) // Fix the toolbar's background.
             .timelineMediaPreview(viewModel: $context.mediaPreviewViewModel)
@@ -53,6 +54,24 @@ struct ThreadTimelineScreen: View {
         }
     }
     
+    @ToolbarContentBuilder
+    private var toolbar: some ToolbarContent {
+        // .principal + .primaryAction works better than .navigation leading + trailing
+        // as the latter disables interaction in the action button for rooms with long names
+        ToolbarItem(placement: .principal) {
+            RoomHeaderView(roomName: L10n.commonThread,
+                           roomSubtitle: context.viewState.roomTitle,
+                           roomAvatar: context.viewState.roomAvatar,
+                           dmRecipientVerificationState: context.viewState.dmRecipientVerificationState,
+                           mediaProvider: context.mediaProvider)
+                // Using a button stops it from getting truncated in the navigation bar
+                .contentShape(.rect)
+        }
+        if #available(iOS 26, *) {
+            ToolbarSpacer()
+        }
+    }
+    
     private var isAtBottomAndLive: Bool {
         timelineContext.isScrolledToBottom && timelineContext.viewState.timelineState.isLive
     }

ElementX/Sources/Screens/Timeline/View/ItemMenu/TimelineItemMenuActionProvider.swift

@@ -50,7 +50,9 @@ struct TimelineItemMenuActionProvider {
 
         if item.canBeRepliedTo, canCurrentUserSendMessage {
             if let messageItem = item as? EventBasedMessageTimelineItemProtocol {
-                actions.append(.reply(isThread: messageItem.properties.isThreaded))
+                // If threads are enabled we will have the dedicated `replyInThread` action
+                // so there is no need to make the normal reply use the thread.
+                actions.append(.reply(isThread: areThreadsEnabled ? false : messageItem.properties.isThreaded))
             } else {
                 actions.append(.reply(isThread: false))
             }