PythonQtMisc.h

#ifndef _PYTHONQTMISC_H
#define _PYTHONQTMISC_H

/*
 *
 *  Copyright (C) 2010 MeVis Medical Solutions AG All Rights Reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  Further, this software is distributed without any warranty that it is
 *  free of the rightful claim of any third person regarding infringement
 *  or the like.  Any license provided herein, whether implied or
 *  otherwise, applies only to this software file.  Patent licenses, if
 *  any, provided herein do not apply to combinations of this program with
 *  other software, or any other product whatsoever.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Contact information: MeVis Medical Solutions AG, Universitaetsallee 29,
 *  28359 Bremen, Germany or:
 *
 *  http://www.mevis.de
 *
 */

//----------------------------------------------------------------------------------
/*!
// \file    PythonQtMisc.h
// \author  Florian Link
// \author  Last changed by $Author: florian $
// \date    2006-05
*/
//----------------------------------------------------------------------------------

#include "PythonQtPythonInclude.h"
#include <vector>
#include <QVariant>

#define PYTHONQT_MAX_ARGS 32

#define PythonQtArgumentFrame_ADD_VALUE(store, type, value, ptr) \
  { \
    type* item = (type*)store->nextPODPtr(); \
    *item = value; \
    ptr = (void*)item; \
  }

#define PythonQtArgumentFrame_ADD_VALUE_IF_NEEDED(alreadyAllocatedPtr, store, type, value, ptr) \
  { \
    type* item = (type*)(alreadyAllocatedPtr ? alreadyAllocatedPtr : store->nextPODPtr()); \
    *item = value; \
    ptr = (void*)item; \
  }

#define PythonQtArgumentFrame_ADD_VARIANT_VALUE(store, value, ptr) \
  { \
    QVariant* item = store->nextVariantPtr(); \
    *item = value; \
    ptr = (void*)item; \
  }

#if QT_VERSION >= 0x060000

  #define PythonQtArgumentFrame_ADD_VARIANT_VALUE_BY_ID(store, id, ptr) \
    PythonQtArgumentFrame_ADD_VARIANT_VALUE(store, QVariant(QMetaType(id)), ptr)

#else

  #define PythonQtArgumentFrame_ADD_VARIANT_VALUE_BY_ID(store, id, ptr) \
    PythonQtArgumentFrame_ADD_VARIANT_VALUE(store, QVariant::Type(id), ptr)

#endif

#define PythonQtArgumentFrame_ADD_VARIANT_VALUE_IF_NEEDED(alreadyAllocatedPtr, store, value, ptr) \
  { \
    QVariant* item = (QVariant*)(alreadyAllocatedPtr ? alreadyAllocatedPtr : store->nextVariantPtr()); \
    *item = value; \
    ptr = (void*)item; \
  }

#if QT_VERSION >= 0x060000

  #define PythonQtArgumentFrame_ADD_VARIANT_VALUE_BY_ID_IF_NEEDED(alreadyAllocatedPtr, store, id, ptr) \
    PythonQtArgumentFrame_ADD_VARIANT_VALUE_IF_NEEDED(alreadyAllocatedPtr, store, QVariant(QMetaType(id)), ptr)

#else

  #define PythonQtArgumentFrame_ADD_VARIANT_VALUE_BY_ID_IF_NEEDED(alreadyAllocatedPtr, store, id, ptr) \
    PythonQtArgumentFrame_ADD_VARIANT_VALUE_IF_NEEDED(alreadyAllocatedPtr, store, QVariant::Type(id), ptr)

#endif

//! Stores C++ arguments for a qt_metacall (which are created when converting data from Python to C++)
class PythonQtArgumentFrame
{

public:
  //! Create a new (empty) frame (which is typically reused from a freelist)
  static PythonQtArgumentFrame* newFrame();
  //! Frees the frame (resetting it and putting it back to the freelist)
  static void deleteFrame(PythonQtArgumentFrame* frame);

  //! Frees all PythonQtArgumentFrame frames that are stored.
  static void cleanupFreeList();

  //! Resets the pod and variant argument lists to empty lists.
  void reset();

  //! Get next pointer to a variant
  QVariant* nextVariantPtr();
  //! Get next pointer to a POD.
  quint64* nextPODPtr();

  template<typename Class>
  void* establishPersistentPtr(void* alreadyAllocatedPtr, const Class& value)
  {
    if (alreadyAllocatedPtr) {
      *reinterpret_cast<Class*>(alreadyAllocatedPtr) = value;
      return alreadyAllocatedPtr;
    } else {
      QVariant* item = nextVariantPtr();
      *item = QVariant(value);
      return const_cast<void*>(item->constData());
    }
  }

  template<typename Class, typename ViewClass>
  void* establishPersistentViewPtr(void* alreadyAllocatedPtr, const Class& value)
  {
    QVariant* itemStore = nextVariantPtr();
    *itemStore = QVariant(value);
    if (alreadyAllocatedPtr) {
      *reinterpret_cast<ViewClass*>(alreadyAllocatedPtr) =
        ViewClass(*reinterpret_cast<const Class*>(itemStore->constData()));
      return alreadyAllocatedPtr;
    } else {
      QVariant* item = nextVariantPtr();
      *item = QVariant::fromValue(ViewClass(*reinterpret_cast<const Class*>(itemStore->constData())));
      return const_cast<void*>(item->constData());
    }
  }

private:
  PythonQtArgumentFrame();
  ~PythonQtArgumentFrame();

  std::vector<quint64> _podArgs;
  std::vector<QVariant> _variantArgs;

  PythonQtArgumentFrame* _freeListNext;

  static PythonQtArgumentFrame* _freeListHead;
};

#endif