--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Messages/ICallable.h	Fri Sep 14 16:44:01 2018 +0200
@@ -0,0 +1,92 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "IMessage.h"
+
+#include <boost/noncopyable.hpp>
+
+namespace OrthancStone {
+
+  class IObserver;
+
+  // This is referencing an object and member function that can be notified
+  // by an IObservable.  The object must derive from IO
+  // The member functions must be of type "void Function(const IMessage& message)" or reference a derived class of IMessage
+  class ICallable : public boost::noncopyable
+  {
+  public:
+    virtual ~ICallable()
+    {
+    }
+
+    virtual void Apply(const IMessage& message) = 0;
+
+    virtual MessageType GetMessageType() const = 0;
+    virtual IObserver* GetObserver() const = 0;
+  };
+
+  template <typename TMessage>
+  class MessageHandler: public ICallable
+  {
+  };
+
+
+  template <typename TObserver,
+            typename TMessage>
+  class Callable : public MessageHandler<TMessage>
+  {
+  private:
+    typedef void (TObserver::* MemberFunction) (const TMessage&);
+
+    TObserver&      observer_;
+    MemberFunction  function_;
+
+  public:
+    Callable(TObserver& observer,
+             MemberFunction function) :
+      observer_(observer),
+      function_(function)
+    {
+    }
+
+    void ApplyInternal(const TMessage& message)
+    {
+      (observer_.*function_) (message);
+    }
+
+    virtual void Apply(const IMessage& message)
+    {
+      ApplyInternal(dynamic_cast<const TMessage&>(message));
+    }
+
+    virtual MessageType GetMessageType() const
+    {
+      return static_cast<MessageType>(TMessage::Type);
+    }
+
+    virtual IObserver* GetObserver() const
+    {
+      return &observer_;
+    }
+  };
+}