/* -*- 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"

 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:

   TraceSourceAccessor ();

   virtual ~TraceSourceAccessor ();

   void Ref (void) const;

   void Unref (void) const;

   /**

    * \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;

 private:

   mutable uint32_t m_count;

 };

 /**

  * \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 */