feat: Enhance drawing functionality with sender tracking and sharing capabilities

lib/providers/app_provider.dart

@@ -4,14 +4,17 @@ import 'package:shared_preferences/shared_preferences.dart';
 import 'connection_provider.dart';
 import 'contacts_provider.dart';
 import 'messages_provider.dart';
+import 'drawing_provider.dart';
 import '../services/tile_cache_service.dart';
 import '../models/contact.dart';
+import '../utils/drawing_message_parser.dart';
 
 /// Main App Provider - coordinates all other providers
 class AppProvider with ChangeNotifier {
   final ConnectionProvider connectionProvider;
   final ContactsProvider contactsProvider;
   final MessagesProvider messagesProvider;
+  final DrawingProvider drawingProvider;
   final TileCacheService tileCacheService;
 
   bool _isInitialized = false;
@@ -21,6 +24,7 @@ class AppProvider with ChangeNotifier {
     required this.connectionProvider,
     required this.contactsProvider,
     required this.messagesProvider,
+    required this.drawingProvider,
     required this.tileCacheService,
   }) {
     _setupCallbacks();
@@ -61,6 +65,20 @@ class AppProvider with ChangeNotifier {
 
     // When a message is received
     connectionProvider.onMessageReceived = (message) {
+      // Check if message is a drawing broadcast
+      if (DrawingMessageParser.isDrawingMessage(message.text)) {
+        debugPrint('🎨 [AppProvider] Drawing message received, parsing...');
+        final drawing = DrawingMessageParser.parseDrawingMessage(message.text);
+        if (drawing != null) {
+          debugPrint('🎨 [AppProvider] Drawing parsed successfully: ${drawing.type.name} from ${drawing.senderName ?? "unknown"}');
+          drawingProvider.addReceivedDrawing(drawing);
+        } else {
+          debugPrint('⚠️ [AppProvider] Failed to parse drawing message');
+        }
+        // Don't add drawing messages to the message list
+        return;
+      }
+
       // Pass contact lookup function to link channel messages with contacts
       messagesProvider.addMessage(
         message,

lib/providers/drawing_provider.dart

@@ -1,8 +1,10 @@
 import 'dart:convert';
+import 'dart:typed_data';
 import 'package:flutter/material.dart';
 import 'package:latlong2/latlong.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import '../models/map_drawing.dart';
+import '../utils/drawing_message_parser.dart';
 
 /// Drawing mode state
 enum DrawingMode {
@@ -255,4 +257,23 @@ class DrawingProvider with ChangeNotifier {
     }
     return null;
   }
+
+  /// Add received drawing from another node
+  void addReceivedDrawing(MapDrawing drawing) {
+    // Check if drawing with this ID already exists
+    if (_drawings.any((d) => d.id == drawing.id)) {
+      debugPrint('Drawing ${drawing.id} already exists, skipping');
+      return;
+    }
+
+    _drawings.add(drawing);
+    _saveDrawings();
+    notifyListeners();
+  }
+
+  /// Broadcast a drawing to contacts
+  /// Returns the formatted message string ready to send
+  String createDrawingBroadcastMessage(MapDrawing drawing, String senderName) {
+    return DrawingMessageParser.createDrawingMessage(drawing, senderName);
+  }
 }