initial work on message threads

Author: martinmitrevski

Sources/StreamChatSwiftUI/ChatChannel/ChannelHeader/MessageThreadHeaderViewModifier.swift

@@ -0,0 +1,37 @@
+//
+// Copyright © 2021 Stream.io Inc. All rights reserved.
+//
+
+import StreamChat
+import SwiftUI
+
+/// View modifier for customizing the message thread header.
+public protocol MessageThreadHeaderViewModifier: ViewModifier {}
+
+/// The default message thread header.
+public struct DefaultMessageThreadHeader: ToolbarContent {
+    @Injected(\.fonts) private var fonts
+    @Injected(\.colors) private var colors
+    
+    public var body: some ToolbarContent {
+        ToolbarItem(placement: .principal) {
+            VStack {
+                Text(L10n.Message.Actions.threadReply)
+                    .font(fonts.bodyBold)
+                Text(L10n.Message.Threads.subtitle)
+                    .font(fonts.footnote)
+                    .foregroundColor(Color(colors.textLowEmphasis))
+            }
+        }
+    }
+}
+
+/// The default message thread header modifier.
+public struct DefaultMessageThreadHeaderModifier: MessageThreadHeaderViewModifier {
+    
+    public func body(content: Content) -> some View {
+        content.toolbar {
+            DefaultMessageThreadHeader()
+        }
+    }
+}

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelDataSource.swift

@@ -0,0 +1,117 @@
+//
+// Copyright © 2021 Stream.io Inc. All rights reserved.
+//
+
+import StreamChat
+
+protocol MessagesDataSource: AnyObject {
+    
+    func dataSource(
+        channelDataSource: ChannelDataSource,
+        didUpdateMessages messages: LazyCachedMapCollection<ChatMessage>
+    )
+    
+    func dataSource(
+        channelDataSource: ChannelDataSource,
+        didUpdateChannel channel: EntityChange<ChatChannel>,
+        channelController: ChatChannelController
+    )
+}
+
+protocol ChannelDataSource: AnyObject {
+    
+    var delegate: MessagesDataSource? { get set }
+    
+    var messages: LazyCachedMapCollection<ChatMessage> { get }
+    
+    func loadPreviousMessages(
+        before messageId: MessageId?,
+        limit: Int,
+        completion: ((Error?) -> Void)?
+    )
+}
+
+class ChatChannelDataSource: ChannelDataSource, ChatChannelControllerDelegate {
+
+    let controller: ChatChannelController
+    weak var delegate: MessagesDataSource?
+    var messages: LazyCachedMapCollection<ChatMessage> {
+        controller.messages
+    }
+    
+    init(controller: ChatChannelController) {
+        self.controller = controller
+        self.controller.delegate = self
+    }
+    
+    public func channelController(
+        _ channelController: ChatChannelController,
+        didUpdateMessages changes: [ListChange<ChatMessage>]
+    ) {
+        delegate?.dataSource(
+            channelDataSource: self,
+            didUpdateMessages: channelController.messages
+        )
+    }
+    
+    func channelController(
+        _ channelController: ChatChannelController,
+        didUpdateChannel channel: EntityChange<ChatChannel>
+    ) {
+        delegate?.dataSource(
+            channelDataSource: self,
+            didUpdateChannel: channel,
+            channelController: channelController
+        )
+    }
+    
+    func loadPreviousMessages(
+        before messageId: MessageId?,
+        limit: Int,
+        completion: ((Error?) -> Void)?
+    ) {
+        controller.loadPreviousMessages(
+            before: messageId,
+            limit: limit,
+            completion: completion
+        )
+    }
+}
+
+class MessageThreadDataSource: ChannelDataSource, ChatMessageControllerDelegate {
+    
+    let channelController: ChatChannelController
+    let messageController: ChatMessageController
+    weak var delegate: MessagesDataSource?
+    var messages: LazyCachedMapCollection<ChatMessage> {
+        messageController.replies
+    }
+
+    init(
+        channelController: ChatChannelController,
+        messageController: ChatMessageController
+    ) {
+        self.channelController = channelController
+        self.messageController = messageController
+        self.messageController.delegate = self
+    }
+    
+    func messageController(
+        _ controller: ChatMessageController,
+        didChangeReplies changes: [ListChange<ChatMessage>]
+    ) {
+        delegate?.dataSource(channelDataSource: self, didUpdateMessages: controller.replies)
+    }
+    
+    func loadPreviousMessages(
+        before messageId: MessageId?,
+        limit: Int,
+        completion: ((Error?) -> Void)?
+    ) {
+        messageController.loadPreviousReplies(
+            before: messageId,
+            limit: limit,
+            completion: completion
+        )
+    }
+}

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelView.swift

@@ -14,21 +14,28 @@ public struct ChatChannelView<Factory: ViewFactory>: View {
     @State private var messageDisplayInfo: MessageDisplayInfo?
 
     private var factory: Factory
+    private var isInThread: Bool
 
     public init(
         viewFactory: Factory,
-        channelController: ChatChannelController
+        channelController: ChatChannelController,
+        messageController: ChatMessageController? = nil
     ) {
         _viewModel = StateObject(
-            wrappedValue: ViewModelsFactory.makeChannelViewModel(with: channelController)
+            wrappedValue: ViewModelsFactory.makeChannelViewModel(
+                with: channelController,
+                messageController: messageController
+            )
         )
         factory = viewFactory
+        isInThread = messageController != nil
     }
 
     public var body: some View {
         VStack(spacing: 0) {
             MessageListView(
                 factory: factory,
+                channel: viewModel.channel,
                 messages: viewModel.messages,
                 messagesGroupingInfo: viewModel.messagesGroupingInfo,
                 scrolledId: $viewModel.scrolledId,
@@ -52,12 +59,16 @@ public struct ChatChannelView<Factory: ViewFactory>: View {
                 .if(viewModel.reactionsShown, transform: { view in
                     view.navigationBarHidden(true)
                 })
-                .if(!viewModel.reactionsShown) { view in
+                .if(!viewModel.reactionsShown && !isInThread) { view in
                     view.modifier(factory.makeChannelHeaderViewModifier(for: viewModel.channel))
                 }
+                .if(!viewModel.reactionsShown && isInThread) { view in
+                    view.modifier(factory.makeMessageThreadHeaderViewModifier())
+                }
 
             factory.makeMessageComposerViewType(
                 with: viewModel.channelController,
+                messageController: viewModel.messageController,
                 onMessageSent: viewModel.scrollToLastMessage
             )
         }

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelViewModel.swift

@@ -7,10 +7,12 @@ import Nuke
 import StreamChat
 import SwiftUI
 
-public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelegate {
+public class ChatChannelViewModel: ObservableObject, MessagesDataSource {
+    
     @Injected(\.chatClient) private var chatClient
     @Injected(\.utils) private var utils
 
+    private var channelDataSource: ChannelDataSource
     private var cancellables = Set<AnyCancellable>()
     private var lastRefreshThreshold = 200
     private let refreshThreshold = 200
@@ -38,6 +40,7 @@ public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelega
     @Atomic private var lastMessageRead: String?
 
     var channelController: ChatChannelController
+    var messageController: ChatMessageController?
 
     @Published var scrolledId: String?
     @Published var listId = UUID().uuidString
@@ -85,9 +88,24 @@ public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelega
         channelController.channel!
     }
 
-    public init(channelController: ChatChannelController) {
+    public init(
+        channelController: ChatChannelController,
+        messageController: ChatMessageController? = nil
+    ) {
         self.channelController = channelController
-        setupChannelController()
+        channelController.synchronize()
+        if let messageController = messageController {
+            self.messageController = messageController
+            messageController.synchronize()
+            channelDataSource = MessageThreadDataSource(
+                channelController: channelController,
+                messageController: messageController
+            )
+        } else {
+            channelDataSource = ChatChannelDataSource(controller: channelController)
+        }
+        channelDataSource.delegate = self
+        messages = channelDataSource.messages
 
         NotificationCenter.default.addObserver(
             self,
@@ -117,13 +135,13 @@ public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelega
         }
     }
 
-    public func channelController(
-        _ channelController: ChatChannelController,
-        didUpdateMessages changes: [ListChange<ChatMessage>]
+    func dataSource(
+        channelDataSource: ChannelDataSource,
+        didUpdateMessages messages: LazyCachedMapCollection<ChatMessage>
     ) {
-        messages = channelController.messages
+        self.messages = messages
 
-        let count = channelController.messages.count
+        let count = messages.count
         if count > lastRefreshThreshold {
             lastRefreshThreshold = lastRefreshThreshold + refreshThreshold
             listId = UUID().uuidString
@@ -134,13 +152,14 @@ public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelega
         }
     }
 
-    public func channelController(
-        _ channelController: ChatChannelController,
-        didUpdateChannel channel: EntityChange<ChatChannel>
+    func dataSource(
+        channelDataSource: ChannelDataSource,
+        didUpdateChannel channel: EntityChange<ChatChannel>,
+        channelController: ChatChannelController
     ) {
         messages = channelController.messages
     }
-    
+
     func showReactionOverlay() {
         guard let view: UIView = topVC()?.view else {
             currentSnapshot = UIImage(systemName: "photo")
@@ -154,19 +173,14 @@ public class ChatChannelViewModel: ObservableObject, ChatChannelControllerDelega
 
     // MARK: - private
 
-    private func setupChannelController() {
-        channelController.delegate = self
-        channelController.synchronize()
-        messages = channelController.messages
-    }
-    
     private func checkForNewMessages(index: Int) {
-        if index < channelController.messages.count - 25 {
+        if index < channelDataSource.messages.count - 25 {
             return
         }
 
         if _loadingPreviousMessages.compareAndSwap(old: false, new: true) {
-            channelController.loadPreviousMessages(
+            channelDataSource.loadPreviousMessages(
+                before: nil,
                 limit: refreshThreshold,
                 completion: { [weak self] _ in
                     guard let self = self else { return }
@@ -222,13 +236,22 @@ extension ChatMessage: Identifiable {
             }
         }
 
-        return baseId + statesId + reactionScoresId
+        return baseId + statesId + reactionScoresId + repliesCountId
     }
 
     private var baseId: String {
         isDeleted ? "\(id)-deleted" : id
     }
 
+    var repliesCountId: String {
+        var repliesCountId = ""
+        if replyCount > 0 {
+            repliesCountId = "\(replyCount)"
+        }
+
+        return repliesCountId
+    }
+    
     var uploadingStatesId: String {
         var states = imageAttachments.compactMap { $0.uploadingState?.state }
         states += giphyAttachments.compactMap { $0.uploadingState?.state }

Sources/StreamChatSwiftUI/ChatChannel/Composer/MessageComposerView.swift

@@ -17,11 +17,15 @@ public struct MessageComposerView<Factory: ViewFactory>: View, KeyboardReadable
     public init(
         viewFactory: Factory,
         channelController: ChatChannelController,
+        messageController: ChatMessageController?,
         onMessageSent: @escaping () -> Void
     ) {
         factory = viewFactory
         _viewModel = StateObject(
-            wrappedValue: ViewModelsFactory.makeMessageComposerViewModel(with: channelController)
+            wrappedValue: ViewModelsFactory.makeMessageComposerViewModel(
+                with: channelController,
+                messageController: messageController
+            )
         )
         self.onMessageSent = onMessageSent
     }
@@ -53,6 +57,13 @@ public struct MessageComposerView<Factory: ViewFactory>: View, KeyboardReadable
             }
             .padding(.all, 8)
 
+            if viewModel.sendInChannelShown {
+                SendInChannelView(
+                    sendInChannel: $viewModel.showReplyInChannel,
+                    isDirectMessage: viewModel.isDirectChannel
+                )
+            }
+            
             factory.makeAttachmentPickerView(
                 attachmentPickerState: $viewModel.pickerState,
                 filePickerShown: $viewModel.filePickerShown,