Fixed animation glitch

Author: martinmitrevski

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelViewModel.swift

@@ -155,11 +155,13 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
         if let message = messageController?.message {
             var array = Array(messages)
             array.append(message)
-            withAnimation {
-                self.messages = LazyCachedMapCollection(source: array, map: { $0 })
-            }
+            self.messages = LazyCachedMapCollection(source: array, map: { $0 })
         } else {
-            withAnimation {
+            if shouldAnimate(changes: changes) {
+                withAnimation {
+                    self.messages = messages
+                }
+            } else {
                 self.messages = messages
             }
         }
@@ -317,6 +319,20 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
         }
     }
 
+    private func shouldAnimate(changes: [ListChange<ChatMessage>]) -> Bool {
+        for change in changes {
+            switch change {
+            case .insert(_, index: _),
+                 .remove(_, index: _):
+                return true
+            default:
+                log.debug("detected non-animatable change")
+            }
+        }
+        
+        return false
+    }
+    
     deinit {
         messageCachingUtils.clearCache()
     }
@@ -355,7 +371,7 @@ extension ChatMessage: Identifiable {
         states += fileAttachments.compactMap { $0.uploadingState?.state }
 
         if states.isEmpty {
-            return ""
+            return "empty"
         }
 
         let strings = states.map { "\($0)" }

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageContainerView.swift

@@ -77,6 +77,7 @@ struct MessageContainerView<Factory: ViewFactory>: View {
                         isFirst: showsAllInfo,
                         scrolledId: $scrolledId
                     )
+                    .animation(nil)
                     .overlay(
                         reactionsShown ?
                             factory.makeMessageReactionView(
@@ -174,14 +175,10 @@ struct MessageContainerView<Factory: ViewFactory>: View {
         .padding(.horizontal, messageListConfig.messagePaddings.horizontal)
         .padding(.bottom, showsAllInfo || isMessagePinned ? paddingValue : 2)
         .padding(.top, isLast ? paddingValue : 0)
-        .background(isMessagePinned || shouldAnimateBackground ? Color(colors.pinnedBackground) : nil)
+        .background(isMessagePinned ? Color(colors.pinnedBackground) : nil)
         .padding(.bottom, isMessagePinned ? paddingValue / 2 : 0)
     }
-    
-    private var shouldAnimateBackground: Bool {
-        scrolledId == message.messageId
-    }
-    
+        
     private var isMessagePinned: Bool {
         message.pinDetails != nil
     }

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageListHelperViews.swift

@@ -43,6 +43,7 @@ struct MessageDateView: View {
         Text(dateFormatter.string(from: message.createdAt))
             .font(fonts.footnote)
             .foregroundColor(Color(colors.textLowEmphasis))
+            .animation(nil)
     }
 }