placement.hpp

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/*
  PLACEMENT.hpp  -  Key Abstraction: a way to place and locate a Media Object

  Copyright (C)         Lumiera.org
    2008,               Hermann Vosseler <Ichthyostega@web.de>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/


#ifndef MOBJECT_PLACEMENT_H
#define MOBJECT_PLACEMENT_H

#include "lib/error.hpp"
#include "lib/hash-indexed.hpp"
#include "lib/time/timevalue.hpp"
#include "steam/mobject/session/locatingpin.hpp"

#include "steam/asset/pipe.hpp"   

#include <memory>


namespace steam {
namespace mobject {
  
  namespace session{ class MObjectFactory; }
  
  class MObject;
  class ExplicitPlacement;
  
  using std::shared_ptr;
  using std::static_pointer_cast;
  using lib::HashIndexed;
  
  
  
  template<class MO, class B =MObject>
  class Placement ;
  
  
  template<>
  class Placement<MObject,MObject>
    : protected shared_ptr<MObject>
    , public HashIndexed<Placement<MObject>, lib::hash::LuidH >
    {
    protected:
      typedef HashIndexed<Placement<MObject>, lib::hash::LuidH> HashInd;
      typedef shared_ptr<MObject> _SmartPtr;
      typedef void (*Deleter)(MObject*);
      typedef lib::time::Time Time;
      typedef asset::shared_ptr<asset::Pipe> Pipe;   
      
      
      
    public:
      MObject *
      operator->()  const
        {
          ENSURE (*this);
          return _SmartPtr::operator->();
        }
      
      template<class Y>
      bool
      isCompatible ()  const
        {
          return 0 != dynamic_cast<Y*> (get());
        }
      
      template<class Y>
      void
      extendOwnershipTo (shared_ptr<Y>& target)  const
        {
          REQUIRE (isCompatible<Y>());
          target = static_pointer_cast<Y>(*this);
        }
      
      friend bool
      isSharedPointee (Placement const& p1, Placement const& p2)
      {
        return static_cast<const void*> (p1.get())
            == static_cast<const void*> (p2.get());
      }
      
      
      operator string()   const ;
      size_t use_count()  const { return _SmartPtr::use_count(); }
      bool   isValid()    const { return _SmartPtr::use_count(); }
      
      
      virtual ~Placement() {};
      
      
      
      session::LocatingPin chain;
      
      virtual ExplicitPlacement resolve ()  const;
      
      
      Placement (Placement const& ref)
        : _SmartPtr (ref)
        , HashInd()    // creating a new ID!
        , chain(ref.chain)
        { }
      
    protected:
      Placement (MObject & subject, Deleter killer)
        : _SmartPtr (&subject, killer) { };
        
      friend class session::MObjectFactory;
      
      
//  private:
//    /** copy assignment prohibited */
//    Placement& operator= (Placement const&);
    };
  
  
  template<class MO, class B>
  class Placement
    : public Placement<B>
    {
    protected:
      typedef Placement<B> _Parent;
      typedef typename _Parent::template Id<MO> const& _Id;
      typedef typename _Parent::Deleter Deleter;
      typedef typename _Parent::_SmartPtr _SmartPtr;
      
      
      Placement (MO & mo, Deleter killer)
        : _Parent (mo, killer)
        { };
      friend class session::MObjectFactory;
      
    public:
      MO*
      operator-> ()  const
        {
          ENSURE (INSTANCEOF (MO, this->get()));
          return static_cast<MO*>
            (_SmartPtr::operator-> ());
        }
      
      _Id
      getID ()  const  
        {
          return _Parent::template recastID<MO>();
        }
      
    };
  
  
  typedef Placement<MObject> PlacementMO;
  typedef Placement<MObject> PMO;
  
  
  
  /* == free functions == */

  string
  format_PlacementID (PlacementMO const&) ;
  
  
  bool
  isSameDef (PlacementMO const&, PlacementMO const&);
  
  
  
}} // namespace steam::mobject
#endif