improved performance and battery usage on older devices

lib/view/pages/talk/widgets/chat_bubble.dart

@@ -59,6 +59,13 @@ class _ChatBubbleState extends State<ChatBubble>
     with SingleTickerProviderStateMixin, DownloadTrigger<ChatBubble> {
   late ChatMessage message;
 
+  // The parsed message and its widget are only rebuilt when their inputs
+  // change. The bubble itself rebuilds on every chat emit, swipe frame and
+  // keyboard frame; re-running rich-object parsing, linkify/Markdown and emoji
+  // detection each time is what makes long chats stutter.
+  Object? _messageKey;
+  late Widget _messageWidget;
+
   Offset _position = Offset.zero;
   Offset _dragStartPosition = Offset.zero;
   bool _swipeActionArmed = false;
@@ -185,12 +192,34 @@ class _ChatBubbleState extends State<ChatBubble>
     }
   }
 
-  @override
-  Widget build(BuildContext context) {
+  void _updateMessage(BuildContext context) {
+    final style = _messageTextStyle(context);
+    final renderMarkdown =
+        widget.bubbleData.markdown &&
+        widget.bubbleData.messageType ==
+            GetRoomResponseObjectMessageType.comment;
+    final key = (
+      widget.bubbleData,
+      widget.highlightQuery,
+      style,
+      renderMarkdown,
+    );
+    if (key == _messageKey) return;
+    _messageKey = key;
     message = ChatMessage(
       originalMessage: widget.bubbleData.message,
       originalData: widget.bubbleData.messageParameters,
     );
+    _messageWidget = message.getWidget(
+      highlightQuery: widget.highlightQuery,
+      style: style,
+      renderMarkdown: renderMarkdown,
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    _updateMessage(context);
     final showActorDisplayName =
         _rendersAsCommentBubble &&
         widget.chatData.type != GetRoomResponseObjectConversationType.oneToOne;
@@ -277,14 +306,7 @@ class _ChatBubbleState extends State<ChatBubble>
                 actorText: actorText,
                 actorWidget: actorWidget,
                 timeText: timeText,
-                messageWidget: message.getWidget(
-                  highlightQuery: widget.highlightQuery,
-                  style: _messageTextStyle(context),
-                  renderMarkdown:
-                      widget.bubbleData.markdown &&
-                      widget.bubbleData.messageType ==
-                          GetRoomResponseObjectMessageType.comment,
-                ),
+                messageWidget: _messageWidget,
                 parent: parent,
                 bubbleData: widget.bubbleData,
                 isSender: widget.isSender,
@@ -350,10 +372,12 @@ class _BubbleContent extends StatelessWidget {
   Widget build(BuildContext context) => MergeSemantics(
     child: Container(
       constraints: BoxConstraints(
-        maxWidth: MediaQuery.of(context).size.width * 0.9,
+        maxWidth: MediaQuery.sizeOf(context).width * 0.9,
         minWidth: showActorDisplayName
-            ? actorText.size.width
-            : timeText.size.width + (isSender ? spacing + timeIconSize : 0) + 3,
+            ? actorText.measuredWidth(context)
+            : timeText.measuredWidth(context) +
+                  (isSender ? spacing + timeIconSize : 0) +
+                  3,
       ),
       child: Stack(
         children: [

lib/view/pages/talk/widgets/chat_bubble_reactions.dart

@@ -34,7 +34,7 @@ class ChatBubbleReactions extends StatelessWidget {
     return Transform.translate(
       offset: const Offset(0, -10),
       child: Container(
-        width: MediaQuery.of(context).size.width,
+        width: MediaQuery.sizeOf(context).width,
         margin: const EdgeInsets.only(left: 15, right: 15),
         child: Wrap(
           alignment: isSender ? WrapAlignment.end : WrapAlignment.start,

lib/view/pages/talk/widgets/chat_textfield.dart

@@ -83,12 +83,20 @@ class _ChatTextfieldState extends State<ChatTextfield> {
     );
   }
 
+  /// Called per keystroke, so the text itself is saved silently; only a draft
+  /// appearing or disappearing notifies listeners (the chat list's marker).
   void _setDraft(String text) {
-    final talkSettings = settings.val(write: true).talkSettings;
+    final drafts = settings.val().talkSettings.drafts;
+    final hadDraft = drafts.containsKey(widget.sendToToken);
     if (text.isNotEmpty) {
-      talkSettings.drafts[widget.sendToToken] = text;
+      drafts[widget.sendToToken] = text;
     } else {
-      talkSettings.drafts.removeWhere((key, _) => key == widget.sendToToken);
+      drafts.remove(widget.sendToToken);
+    }
+    if (hadDraft != text.isNotEmpty) {
+      settings.val(write: true);
+    } else {
+      settings.saveSilently();
     }
   }
 
@@ -276,17 +284,22 @@ class _ChatTextfieldState extends State<ChatTextfield> {
 
   @override
   Widget build(BuildContext context) {
-    final chatBloc = context.watch<ChatBloc>();
-    final chatState = chatBloc.state.data;
+    final chatBloc = context.read<ChatBloc>();
+    // Only the reply reference is rendered from the chat state; loading flags
+    // and paging emits don't need to rebuild the input.
+    final (referenceMessageId, chatResponse) = context.select(
+      (ChatBloc b) => (
+        b.state.data?.referenceMessageId,
+        b.state.data?.chatResponse,
+      ),
+    );
 
     Widget replyBanner = const SizedBox.shrink();
-    if (chatState != null &&
-        chatState.referenceMessageId != null &&
-        chatState.chatResponse != null) {
+    if (referenceMessageId != null && chatResponse != null) {
       try {
-        final referenceMessage = chatState.chatResponse!
-            .sortByTimestamp()
-            .firstWhere((e) => e.id == chatState.referenceMessageId);
+        final referenceMessage = chatResponse.data.firstWhere(
+          (e) => e.id == referenceMessageId,
+        );
         replyBanner = Row(
           children: [
             Expanded(

lib/view/pages/talk/widgets/chat_tile.dart

@@ -68,15 +68,25 @@ class _ChatTileState extends State<ChatTile> {
   /// One-line preview of the last message: rich-object placeholders resolved,
   /// newlines flattened and — for Markdown messages — formatting stripped so
   /// the list shows readable text rather than raw markers.
+  ///
+  /// Memoised per last message: the tile rebuilds on every chat-list emit and
+  /// the Markdown strip is a full parse. Keyed by content, since every refresh
+  /// delivers new message objects.
   String _lastMessagePreview() {
     final last = widget.data.lastMessage;
+    final key = (last.id, last.message, last.markdown);
+    if (key == _previewFor) return _preview;
     final text = RichObjectStringProcessor.parseToString(
       last.message.replaceAll('\n', ' '),
       last.messageParameters,
     );
-    return last.markdown ? markdownToPlainText(text) : text;
+    _previewFor = key;
+    return _preview = last.markdown ? markdownToPlainText(text) : text;
   }
 
+  Object? _previewFor;
+  String _preview = '';
+
   Future<void> _setCurrentAsRead() async {
     final token = widget.data.token;
     final lastId = widget.data.lastMessage.id;
@@ -89,7 +99,11 @@ class _ChatTileState extends State<ChatTile> {
 
   @override
   Widget build(BuildContext context) {
-    final chatBloc = context.watch<ChatBloc>();
+    // Only the open token matters here (split-view highlight); watching the
+    // whole bloc rebuilt every tile on each message of the open chat.
+    final currentToken = context.select(
+      (ChatBloc b) => b.state.data?.currentToken,
+    );
     final isGroup =
         widget.data.type != GetRoomResponseObjectConversationType.oneToOne;
     final circleAvatar = UserAvatar(
@@ -100,7 +114,7 @@ class _ChatTileState extends State<ChatTile> {
     return ListTile(
       style: ListTileStyle.list,
       tileColor:
-          chatBloc.state.data?.currentToken == widget.data.token &&
+          currentToken == widget.data.token &&
               TalkNavigator.isSecondaryVisible(context)
           ? Theme.of(context).primaryColor.withAlpha(100)
           : null,