implemented in-chat search with text highlighting, added search navigation UI, and integrated scrollable list for message jumping

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

@@ -1,12 +1,12 @@
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_linkify/flutter_linkify.dart';
 
 import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
 import '../../../../model/account_data.dart';
 import '../../../../model/endpoint_data.dart';
 import '../../../../utils/url_opener.dart';
+import '../widgets/highlighted_linkify.dart';
 
 class ChatMessage {
   String originalMessage;
@@ -27,8 +27,13 @@ class ChatMessage {
     );
   }
 
-  Widget getWidget() {
-    var contentWidget = Linkify(text: content, onOpen: UrlOpener.onOpen);
+  Widget getWidget({String? highlightQuery, TextStyle? style}) {
+    var contentWidget = HighlightedLinkify(
+      text: content,
+      onOpen: UrlOpener.onOpen,
+      highlight: highlightQuery,
+      style: style,
+    );
 
     if (originalData?['object']?.type == RichObjectStringObjectType.talkPoll) {
       return ListTile(

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

@@ -0,0 +1,49 @@
+import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
+import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
+import '../../../../api/marianumcloud/talk/room/get_room_response.dart';
+
+class ChatSearchMatch {
+  final int messageId;
+  final int timestamp;
+
+  const ChatSearchMatch({required this.messageId, required this.timestamp});
+}
+
+class ChatSearchController {
+  static List<ChatSearchMatch> findMatches(
+    GetChatResponse response,
+    String query,
+  ) {
+    final q = query.trim().toLowerCase();
+    if (q.isEmpty) return const [];
+
+    final matches = <ChatSearchMatch>[];
+    for (final element in response.sortByTimestamp()) {
+      if (element.systemMessage.contains('reaction')) continue;
+      if (element.systemMessage.contains('poll_voted')) continue;
+
+      final haystackText = RichObjectStringProcessor.parseToString(
+        element.message,
+        element.messageParameters,
+      ).toLowerCase();
+
+      var matched = haystackText.contains(q);
+      if (!matched &&
+          element.messageType != GetRoomResponseObjectMessageType.system) {
+        matched = element.actorDisplayName.toLowerCase().contains(q);
+      }
+
+      if (matched) {
+        matches.add(
+          ChatSearchMatch(
+            messageId: element.id,
+            timestamp: element.timestamp,
+          ),
+        );
+      }
+    }
+
+    matches.sort((a, b) => b.timestamp.compareTo(a.timestamp));
+    return matches;
+  }
+}