--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Messages/IObservable.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,54 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 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 "../StoneEnumerations.h"
+#include "ICallable.h"
+#include "IObserver.h"
+
+#include <set>
+#include <map>
+
+namespace OrthancStone 
+{
+  class IObservable : public boost::noncopyable
+  {
+  private:
+    typedef std::map<MessageIdentifier, std::set<ICallable*> >  Callables;
+
+    Callables       callables_;
+
+    void EmitMessageInternal(const IObserver* receiver,
+                             const IMessage& message);
+
+  public:
+    virtual ~IObservable();
+
+    // Takes ownership of the callable
+    void RegisterCallable(ICallable* callable);
+
+    void BroadcastMessage(const IMessage& message);
+
+    void EmitMessage(boost::weak_ptr<IObserver> observer,
+                     const IMessage& message);
+  };
+}