refactor: Improve message handling in Unity example by parsing JSON data

This commit enhances the message handling logic in the Unity example by parsing incoming messages as JSON. It updates the method checks to use parsed data, improving robustness and error handling. The changes ensure that speed and state updates are processed correctly, providing a more reliable interaction between Flutter and Unity.

Author: juicycleff

example/lib/main.dart

@@ -537,34 +537,45 @@ class _UnityExampleScreenState extends State<UnityExampleScreen> {
   }
 
   void _onMessage(GameMessage message) {
-    _log('Message received: ${message.method}');
+    _log('Message received: ${message.data}');
 
-    if (message.method == 'onReady') {
+    // Parse the message data
+    final json = message.asJson();
+    if (json == null) return;
+    
+    final method = json['method'] as String?;
+    if (method == null) return;
+    
+    _log('Method: $method');
+    
+    if (method == 'onReady') {
       setState(() {
         _isReady = true;
         _lastMessage = 'Unity cube demo ready!';
         _direction = '← FROM UNITY';
       });
-    } else if (message.method == 'onSpeedChanged') {
+    } else if (method == 'onSpeedChanged') {
       try {
-        final data = message.data as Map<String, dynamic>;
-        setState(() {
-          _currentSpeed = (data['speed'] as num).toDouble();
-          _currentRpm = (data['rpm'] as num).toDouble();
-          _lastMessage = 'Speed updated';
-          _direction = '← FROM UNITY';
-        });
+        final data = json['data'] as Map<String, dynamic>?;
+        if (data != null) {
+          setState(() {
+            _currentSpeed = (data['speed'] as num?)?.toDouble() ?? 0;
+            _currentRpm = (data['rpm'] as num?)?.toDouble() ?? 0;
+            _lastMessage = 'Speed updated';
+            _direction = '← FROM UNITY';
+          });
+        }
       } catch (e) {
         _log('Error parsing speed data: $e');
       }
-    } else if (message.method == 'onReset') {
+    } else if (method == 'onReset') {
       setState(() {
         _rotationSpeed = 50;
         _rotationAxis = 'Y';
         _lastMessage = 'Cube reset';
         _direction = '← FROM UNITY';
       });
-    } else if (message.method == 'onState') {
+    } else if (method == 'onState') {
       setState(() {
         _lastMessage = 'State received';
         _direction = '← FROM UNITY';