Bubble up child messages

Ooui/EventTarget.cs

@@ -100,9 +100,12 @@ namespace Ooui
             return $"{IdPrefix}{id}";
         }
 
-        public virtual void Send (Message message)
+        public void Send (Message message)
         {
-            SaveStateMessageIfNeeded (message);
+            if (message == null)
+                return;
+            if (message.TargetId == Id)
+                SaveStateMessageIfNeeded (message);
             MessageSent?.Invoke (message);
         }
 
@@ -121,7 +124,7 @@ namespace Ooui
             });
         }
 
-        public virtual void Receive (Message message)
+        public void Receive (Message message)
         {
             if (message == null)
                 return;
@@ -194,7 +197,7 @@ namespace Ooui
 
         public override object ReadJson (Newtonsoft.Json.JsonReader reader, Type objectType, object existingValue, Newtonsoft.Json.JsonSerializer serializer)
         {
-            throw new NotImplementedException ();
+            throw new NotSupportedException ();
         }
 
         public override bool CanConvert (Type objectType)

Ooui/Node.cs

@@ -43,13 +43,15 @@ namespace Ooui
         public Node InsertBefore (Node newChild, Node referenceChild)
         {
             if (referenceChild == null) {
+                newChild.MessageSent += HandleChildMessageSent;
                 children.Add (newChild);                
             }
             else {
                 var index = children.IndexOf (referenceChild);
                 if (index < 0) {
-                    throw new ArgumentException ("Reference must be a child of this element", nameof(referenceChild));
-                }
+                    throw new ArgumentException ("Reference must be a child of this element", nameof (referenceChild));
+                }                
+                newChild.MessageSent += HandleChildMessageSent;
                 children.Insert (index, newChild);
             }
             SendCall ("insertBefore", newChild, referenceChild);
@@ -58,9 +60,12 @@ namespace Ooui
 
         public Node RemoveChild (Node child)
         {
+            if (child == null)
+                return null;
             if (!children.Remove (child)) {
                 throw new ArgumentException ("Child not contained in this element", nameof(child));
             }
+            child.MessageSent -= HandleChildMessageSent;
             SendCall ("removeChild", child);
             return child;
         }
@@ -73,6 +78,11 @@ namespace Ooui
             InsertBefore (newNode, null);
         }
 
+        void HandleChildMessageSent (Message message)
+        {
+            Send (message);
+        }
+
         protected override void SaveStateMessageIfNeeded (Message message)
         {
             switch (message.MessageType) {