Add thread selection logic to iPad

Author: nuno-vieira

Sources/StreamChatSwiftUI/ChatThreadList/ChatThreadList.swift

@@ -11,6 +11,9 @@ public struct ThreadList<Factory: ViewFactory, HeaderView: View, FooterView: Vie
     var threads: LazyCachedMapCollection<ChatThread>
     private var factory: Factory
     private var threadDestination: (ChatThread) -> Factory.ThreadDestination
+    @Binding private var selectedThread: ThreadSelectionInfo?
+    
+    private var onItemTap: (ChatThread) -> Void
     private var onItemAppear: (Int) -> Void
 
     @ViewBuilder
@@ -23,13 +26,17 @@ public struct ThreadList<Factory: ViewFactory, HeaderView: View, FooterView: Vie
         factory: Factory,
         threads: LazyCachedMapCollection<ChatThread>,
         threadDestination: @escaping (ChatThread) -> Factory.ThreadDestination,
+        selectedThread: Binding<ThreadSelectionInfo?>,
+        onItemTap: @escaping (ChatThread) -> Void,
         onItemAppear: @escaping (Int) -> Void,
         headerView: @escaping () -> HeaderView,
         footerView: @escaping () -> FooterView
     ) {
         self.factory = factory
         self.threads = threads
         self.threadDestination = threadDestination
+        self._selectedThread = selectedThread
+        self.onItemTap = onItemTap
         self.onItemAppear = onItemAppear
         self.headerView = headerView
         self.footerView = footerView
@@ -42,6 +49,8 @@ public struct ThreadList<Factory: ViewFactory, HeaderView: View, FooterView: Vie
                 factory: factory,
                 threads: threads,
                 threadDestination: threadDestination,
+                selectedThread: $selectedThread, 
+                onItemTap: onItemTap,
                 onItemAppear: onItemAppear
             )
             footerView()
@@ -54,27 +63,38 @@ public struct ThreadsLazyVStack<Factory: ViewFactory>: View {
     private var factory: Factory
     var threads: LazyCachedMapCollection<ChatThread>
     private var threadDestination: (ChatThread) -> Factory.ThreadDestination
+    @Binding private var selectedThread: ThreadSelectionInfo?
+    private var onItemTap: (ChatThread) -> Void
     private var onItemAppear: (Int) -> Void
 
     public init(
         factory: Factory,
         threads: LazyCachedMapCollection<ChatThread>,
         threadDestination: @escaping (ChatThread) -> Factory.ThreadDestination,
+        selectedThread: Binding<ThreadSelectionInfo?>,
+        onItemTap: @escaping (ChatThread) -> Void,
         onItemAppear: @escaping (Int) -> Void
     ) {
         self.factory = factory
         self.threads = threads
         self.threadDestination = threadDestination
+        self.onItemTap = onItemTap
         self.onItemAppear = onItemAppear
+        self._selectedThread = selectedThread
     }
 
     public var body: some View {
         LazyVStack(spacing: 0) {
             ForEach(threads) { thread in
                 factory.makeThreadListItem(
                     thread: thread,
-                    threadDestination: threadDestination
+                    threadDestination: threadDestination,
+                    selectedThread: $selectedThread
                 )
+                .contentShape(Rectangle())
+                .onTapGesture {
+                    onItemTap(thread)
+                }
                 .onAppear {
                     if let index = threads.firstIndex(where: { chatThread in
                         chatThread.id == thread.id

Sources/StreamChatSwiftUI/ChatThreadList/ChatThreadListNavigatableItem.swift

@@ -12,31 +12,60 @@ public struct ChatThreadListNavigatableItem<ThreadListItem: View, ThreadDestinat
     private var threadListItem: ThreadListItem
     private var threadDestination: (ChatThread) -> ThreadDestination
     private var handleTabBarVisibility: Bool
+    @Binding private var selectedThread: ThreadSelectionInfo?
 
     public init(
         thread: ChatThread,
         threadListItem: ThreadListItem,
         threadDestination: @escaping (ChatThread) -> ThreadDestination,
+        selectedThread: Binding<ThreadSelectionInfo?>,
         handleTabBarVisibility: Bool
     ) {
         self.thread = thread
         self.threadListItem = threadListItem
         self.threadDestination = threadDestination
+        self._selectedThread = selectedThread
         self.handleTabBarVisibility = handleTabBarVisibility
     }
 
     public var body: some View {
-        NavigationLink(
-            destination: {
-                threadDestination(thread)
-                    .modifier(HideTabBarModifier(
-                        handleTabBarVisibility: handleTabBarVisibility
-                    ))
-            },
-            label: {
-                threadListItem
+        ZStack {
+            threadListItem
+            NavigationLink(
+                tag: ThreadSelectionInfo(thread: thread),
+                selection: $selectedThread
+            ) {
+                LazyView(
+                    threadDestination(thread)
+                        .modifier(HideTabBarModifier(
+                            handleTabBarVisibility: handleTabBarVisibility
+                        ))
+                )
+            } label: {
+                EmptyView()
             }
-        )
+        }
         .foregroundColor(.black)
     }
 }
+
+public struct ThreadSelectionInfo: Identifiable {
+    public let id: String
+    public let thread: ChatThread
+
+    public init(thread: ChatThread) {
+        self.thread = thread
+        self.id = thread.id
+    }
+}
+
+extension ThreadSelectionInfo: Hashable, Equatable {
+
+    public static func == (lhs: ThreadSelectionInfo, rhs: ThreadSelectionInfo) -> Bool {
+        lhs.id == rhs.id
+    }
+
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(id)
+    }
+}

Sources/StreamChatSwiftUI/ChatThreadList/ChatThreadListView.swift

@@ -111,7 +111,11 @@ public struct ChatThreadListContentView<Factory: ViewFactory>: View {
         ThreadList(
             factory: viewFactory,
             threads: viewModel.threads,
-            threadDestination: viewFactory.makeThreadDestination(),
+            threadDestination: viewFactory.makeThreadDestination(), 
+            selectedThread: $viewModel.selectedThread,
+            onItemTap: { thread in
+                viewModel.selectedThread = .init(thread: thread)
+            },
             onItemAppear: { index in
                 viewModel.didAppearThread(at: index)
             }, 

Sources/StreamChatSwiftUI/ChatThreadList/ChatThreadListViewModel.swift

@@ -23,6 +23,9 @@ open class ChatThreadListViewModel: ObservableObject, ChatThreadListControllerDe
     /// A boolean value indicating if the initial threads have been loaded.
     public private(set) var hasLoadedThreads = false
 
+    /// The current selected thread.
+    @Published public var selectedThread: ThreadSelectionInfo?
+
     /// The list of threads.
     @Published public var threads = LazyCachedMapCollection<ChatThread>()
 
@@ -108,12 +111,14 @@ open class ChatThreadListViewModel: ObservableObject, ChatThreadListControllerDe
         isLoading = threadListController.threads.isEmpty == true
         failedToLoadThreads = false
         isReloading = !isEmpty
+        preselectThreadIfNeeded()
         threadListController.synchronize { [weak self] error in
             self?.isLoading = false
             self?.isReloading = false
             self?.hasLoadedThreads = error == nil
             self?.failedToLoadThreads = error != nil
             self?.isEmpty = self?.threadListController.threads.isEmpty == true
+            self?.preselectThreadIfNeeded()
             self?.hasLoadedAllThreads = self?.threadListController.hasLoadedAllThreads ?? false
             if error == nil {
                 self?.newAvailableThreadIds = []
@@ -172,4 +177,12 @@ open class ChatThreadListViewModel: ObservableObject, ChatThreadListControllerDe
     private func makeDefaultEventsController() {
         eventsController = chatClient.eventsController()
     }
+
+    private func preselectThreadIfNeeded() {
+        guard isIPad else { return }
+        guard let firstThread = threads.first else { return }
+        guard selectedThread == nil else { return }
+
+        selectedThread = .init(thread: firstThread)
+    }
 }

Sources/StreamChatSwiftUI/DefaultViewFactory.swift

@@ -981,12 +981,14 @@ extension ViewFactory {
 
     public func makeThreadListItem(
         thread: ChatThread,
-        threadDestination: @escaping (ChatThread) -> ThreadDestination
+        threadDestination: @escaping (ChatThread) -> ThreadDestination,
+        selectedThread: Binding<ThreadSelectionInfo?>
     ) -> some View {
         ChatThreadListNavigatableItem(
             thread: thread,
             threadListItem: ChatThreadListItem(thread: thread),
-            threadDestination: threadDestination,
+            threadDestination: threadDestination, 
+            selectedThread: selectedThread,
             handleTabBarVisibility: true
         )
     }

Sources/StreamChatSwiftUI/ViewFactory.swift

@@ -997,9 +997,11 @@ public protocol ViewFactory: AnyObject {
     /// - Parameters:
     ///  - thread: The thread being displayed.
     ///  - threadDestination: A closure that creates the thread destination.
+    ///  - selectedThread: The binding of the currently selected thread.
     func makeThreadListItem(
         thread: ChatThread,
-        threadDestination: @escaping (ChatThread) -> ThreadDestination
+        threadDestination: @escaping (ChatThread) -> ThreadDestination,
+        selectedThread: Binding<ThreadSelectionInfo?>
     ) -> ThreadListItemType
 
     associatedtype NoThreads: View