Improve list updates (#522)

Author: laevandus

CHANGELOG.md

@@ -3,7 +3,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 # Upcoming
 
-### 🔄 Changed
+### 🐞 Fixed
+- Smoother and more performant view updates in channel and message lists [#522](https://github.com/GetStream/stream-chat-swiftui/pull/522)
 
 # [4.58.0](https://github.com/GetStream/stream-chat-swiftui/releases/tag/4.58.0)
 _June 27, 2024_

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelViewModel.swift

@@ -273,12 +273,19 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
             scrolledId = nil
             return true
         } else {
-            guard let baseId = messageId.components(separatedBy: "$").first else {
+            let findBaseId: String? = {
+                if StreamRuntimeCheck._isDatabaseObserverItemReusingEnabled {
+                    return messageId
+                } else {
+                    return messageId.components(separatedBy: "$").first
+                }
+            }()
+            guard let baseId = findBaseId else {
                 scrolledId = nil
                 return true
             }
             let alreadyLoaded = messages.map(\.id).contains(baseId)
-            if alreadyLoaded && baseId != messageId {
+            if alreadyLoaded {
                 if scrolledId == nil {
                     scrolledId = messageId
                 }
@@ -405,12 +412,16 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
             return
         }
 
-        let animationState = shouldAnimate(changes: changes)
-        if animationState == .animated {
+        // Set unread state before updating messages for ensuring the state is up to date before `handleMessageAppear` is called
+        if lastReadMessageId != nil && firstUnreadMessageId == nil {
+            firstUnreadMessageId = channelDataSource.firstUnreadMessageId
+        }
+        
+        if shouldAnimate(changes: changes) {
             withAnimation {
                 self.messages = messages
             }
-        } else if animationState == .notAnimated {
+        } else {
             self.messages = messages
         }
 
@@ -419,10 +430,6 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
         if !showScrollToLatestButton && scrolledId == nil && !loadingNextMessages {
             updateScrolledIdToNewestMessage()
         }
-        
-        if lastReadMessageId != nil && firstUnreadMessageId == nil {
-            firstUnreadMessageId = channelDataSource.firstUnreadMessageId
-        }
     }
 
     func dataSource(
@@ -649,42 +656,35 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
         }
     }
 
-    private func shouldAnimate(changes: [ListChange<ChatMessage>]) -> AnimationChange {
+    private func shouldAnimate(changes: [ListChange<ChatMessage>]) -> Bool {
         if !utils.messageListConfig.messageDisplayOptions.animateChanges || loadingNextMessages {
-            return .notAnimated
+            return false
         }
 
-        var skipChanges = true
         var animateChanges = false
         for change in changes {
             switch change {
             case .insert(_, index: _),
                  .remove(_, index: _):
-                return .animated
+                return true
             case let .update(message, index: index):
+                let animateReactions = message.reactionScoresId != messages[index.row].reactionScoresId
+                    && utils.messageListConfig.messageDisplayOptions.shouldAnimateReactions
                 if index.row < messages.count,
                    message.messageId != messages[index.row].messageId
                    || message.type == .ephemeral
                    || !message.linkAttachments.isEmpty {
-                    skipChanges = false
                     if index.row < messages.count
-                        && (
-                            message.reactionScoresId != messages[index.row].reactionScoresId
-                                && utils.messageListConfig.messageDisplayOptions.shouldAnimateReactions
-                        ) {
+                        && animateReactions {
                         animateChanges = message.linkAttachments.isEmpty
                     }
                 }
             default:
-                skipChanges = false
+                break
             }
         }
 
-        if skipChanges {
-            return .skip
-        }
-        
-        return animateChanges ? .animated : .notAnimated
+        return animateChanges
     }
 
     private func enableDateIndicator() {
@@ -814,12 +814,6 @@ public enum ChannelHeaderType {
     case typingIndicator
 }
 
-enum AnimationChange {
-    case animated
-    case notAnimated
-    case skip
-}
-
 let firstMessageKey = "firstMessage"
 let lastMessageKey = "lastMessage"
 

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageIdBuilder.swift

@@ -16,6 +16,9 @@ public class DefaultMessageIdBuilder: MessageIdBuilder {
     public init() { /* Public init. */ }
 
     public func makeMessageId(for message: ChatMessage) -> String {
+        if StreamRuntimeCheck._isDatabaseObserverItemReusingEnabled {
+            return message.id
+        }
         var statesId = "empty"
         if message.localState != nil {
             statesId = message.uploadingStatesId

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageView.swift

@@ -229,13 +229,19 @@ struct StreamTextView: View {
 
     @Injected(\.fonts) var fonts
 
-    var message: ChatMessage
+    let message: ChatMessage
+    private let adjustedText: String
+    
+    init(message: ChatMessage) {
+        self.message = message
+        adjustedText = message.adjustedText
+    }
 
     var body: some View {
         if #available(iOS 15, *) {
             LinkDetectionTextView(message: message)
         } else {
-            Text(message.adjustedText)
+            Text(adjustedText)
                 .foregroundColor(textColor(for: message))
                 .font(fonts.body)
         }

Sources/StreamChatSwiftUI/ChatChannel/Reactions/MessageActions/DefaultMessageActions.swift

@@ -33,7 +33,7 @@ extension MessageAction {
             )
             return messageActions
         } else if message.localState == .pendingSend
-            && message.messageId.contains("\(LocalAttachmentState.uploadingFailed)") {
+            && message.allAttachments.contains(where: { $0.uploadingState?.state == .uploadingFailed }) {
             messageActions = editAndDeleteActions(
                 for: message,
                 channel: channel,

Sources/StreamChatSwiftUI/StreamChat.swift

@@ -17,7 +17,6 @@ public class StreamChat {
         appearance: Appearance = Appearance(),
         utils: Utils = Utils()
     ) {
-        StreamRuntimeCheck._isDatabaseObserverItemReusingEnabled = false
         self.chatClient = chatClient
         self.appearance = appearance
         self.utils = utils

StreamChatSwiftUITests/Tests/ChatChannel/ChatMessageIDs_Tests.swift

@@ -8,6 +8,16 @@ import XCTest
 
 class ChatMessageIDs_Tests: StreamChatTestCase {
 
+    override func setUpWithError() throws {
+        try super.setUpWithError()
+        StreamRuntimeCheck._isDatabaseObserverItemReusingEnabled = false
+    }
+    
+    override func tearDownWithError() throws {
+        StreamRuntimeCheck._isDatabaseObserverItemReusingEnabled = true
+        try super.tearDownWithError()
+    }
+    
     func test_chatMessage_reactionScoresId() {
         // Given
         let id: String = .unique

StreamChatSwiftUITestsAppTests/Tests/Base TestCase/StreamTestCase.swift

@@ -90,7 +90,7 @@ extension StreamTestCase {
                 return
             }
             server.stop()
-            MockServerConfiguration.port = UInt16(Int.random(in: 61000..<62000))
+            MockServerConfiguration.port = UInt16.random(in: 61000..<62000)
         }
 
         mockServerCrashed = true