--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/core/model/trace-source-accessor.h	Fri Feb 18 16:05:39 2011 -0800
@@ -0,0 +1,143 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2008 INRIA
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
+ */
+#ifndef TRACE_SOURCE_ACCESSOR_H
+#define TRACE_SOURCE_ACCESSOR_H
+
+#include <stdint.h>
+#include "callback.h"
+#include "ptr.h"
+#include "simple-ref-count.h"
+
+namespace ns3 {
+
+class ObjectBase;
+
+/**
+ * \ingroup tracing
+ *
+ * \brief control access to objects' trace sources
+ *
+ * This class abstracts the kind of trace source to which we want to connect
+ * and provides services to Connect and Disconnect a sink to a trace source.
+ */
+class TraceSourceAccessor : public SimpleRefCount<TraceSourceAccessor>
+{
+public:
+  TraceSourceAccessor ();
+  virtual ~TraceSourceAccessor ();
+
+  /**
+   * \param obj the object instance which contains the target trace source.
+   * \param cb the callback to connect to the target trace source.
+   */
+  virtual bool ConnectWithoutContext (ObjectBase *obj, const CallbackBase &cb) const = 0;
+  /**
+   * \param obj the object instance which contains the target trace source.
+   * \param context the context to bind to the user callback.
+   * \param cb the callback to connect to the target trace source.
+   */
+  virtual bool Connect (ObjectBase *obj, std::string context, const CallbackBase &cb) const = 0;
+  /**
+   * \param obj the object instance which contains the target trace source.
+   * \param cb the callback to disconnect from the target trace source.
+   */
+  virtual bool DisconnectWithoutContext (ObjectBase *obj, const CallbackBase &cb) const = 0;
+  /**
+   * \param obj the object instance which contains the target trace source.
+   * \param context the context which was bound to the user callback.
+   * \param cb the callback to disconnect from the target trace source.
+   */
+  virtual bool Disconnect (ObjectBase *obj, std::string context, const CallbackBase &cb) const = 0;
+};
+
+/**
+ * \param a the trace source
+ *
+ * Create a TraceSourceAccessor which will control access to the underlying
+ * trace source. This helper template method assumes that the underlying
+ * type implements a statically-polymorphic set of Connect and Disconnect
+ * methods and creates a dynamic-polymorphic class to wrap the underlying
+ * static-polymorphic class.
+ */
+template <typename T>
+Ptr<const TraceSourceAccessor> MakeTraceSourceAccessor (T a);
+
+} // namespace ns3
+
+namespace ns3 {
+
+template <typename T, typename SOURCE>
+Ptr<const TraceSourceAccessor> 
+DoMakeTraceSourceAccessor (SOURCE T::*a)
+{
+  struct Accessor : public TraceSourceAccessor
+  {
+    virtual bool ConnectWithoutContext (ObjectBase *obj, const CallbackBase &cb) const {
+      T *p = dynamic_cast<T*> (obj);
+      if (p == 0)
+	{
+	  return false;
+	}
+      (p->*m_source).ConnectWithoutContext (cb);
+      return true;
+    }
+    virtual bool Connect (ObjectBase *obj, std::string context, const CallbackBase &cb) const {
+      T *p = dynamic_cast<T*> (obj);
+      if (p == 0)
+	{
+	  return false;
+	}
+      (p->*m_source).Connect (cb, context);
+      return true;
+    }
+    virtual bool DisconnectWithoutContext (ObjectBase *obj, const CallbackBase &cb) const {
+      T *p = dynamic_cast<T*> (obj);
+      if (p == 0)
+	{
+	  return false;
+	}
+      (p->*m_source).DisconnectWithoutContext (cb);
+      return true;      
+    }
+    virtual bool Disconnect (ObjectBase *obj, std::string context, const CallbackBase &cb) const {
+      T *p = dynamic_cast<T*> (obj);
+      if (p == 0)
+	{
+	  return false;
+	}
+      (p->*m_source).Disconnect (cb, context);
+      return true;      
+    }
+    SOURCE T::*m_source;
+  } *accessor = new Accessor ();
+  accessor->m_source = a;
+  return Ptr<const TraceSourceAccessor> (accessor, false);
+}
+
+template <typename T>
+Ptr<const TraceSourceAccessor> MakeTraceSourceAccessor (T a)
+{
+  return DoMakeTraceSourceAccessor (a);
+}
+
+} // namespace ns3
+
+
+#endif /* TRACE_SOURCE_ACCESSOR_H */