markdown support for talk messages

lib/view/pages/talk/data/chat_message.dart

@@ -8,6 +8,7 @@ import '../../../../model/endpoint_data.dart';
 import '../../../../utils/emoji_detection.dart';
 import '../../../../utils/url_opener.dart';
 import '../widgets/highlighted_linkify.dart';
+import '../widgets/message_markdown.dart';
 
 class ChatMessage {
   String originalMessage;
@@ -26,7 +27,11 @@ class ChatMessage {
     );
   }
 
-  Widget getWidget({String? highlightQuery, TextStyle? style}) {
+  Widget getWidget({
+    String? highlightQuery,
+    TextStyle? style,
+    bool renderMarkdown = false,
+  }) {
     final emojiFontSize = standaloneEmojiFontSize(content);
     final effectiveStyle = emojiFontSize == null
         ? style
@@ -35,12 +40,21 @@ class ChatMessage {
             height: 1.15,
           );
 
-    Widget contentWidget = HighlightedLinkify(
-      text: content,
-      onOpen: UrlOpener.onOpen,
-      highlight: highlightQuery,
-      style: effectiveStyle,
-    );
+    // Markdown replaces the plain linkified text only for regular messages.
+    // Emoji-only bodies keep their enlarged rendering, and while searching we
+    // fall back to the linkify path so matches can still be highlighted (the
+    // search highlight can't be threaded through Markdown formatting).
+    final hasQuery = highlightQuery?.trim().isNotEmpty ?? false;
+    final useMarkdown = renderMarkdown && emojiFontSize == null && !hasQuery;
+
+    var contentWidget = useMarkdown
+        ? MessageMarkdown(data: content, style: effectiveStyle)
+        : HighlightedLinkify(
+            text: content,
+            onOpen: UrlOpener.onOpen,
+            highlight: highlightQuery,
+            style: effectiveStyle,
+          );
 
     // Enlarged emoji glyphs otherwise sit flush against the bubble edges.
     if (emojiFontSize != null) {