/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkSmartPyObject.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

// .NAME vtkSmartPyObject
// .SECTION Description
// The vtkSmartPyObject class serves as a smart pointer for PyObjects.

#ifndef vtkSmartPyObject_h
#define vtkSmartPyObject_h

// this must be included first
#include "vtkPython.h" // PyObject can't be forward declared

#include "vtkWrappingPythonCoreModule.h"

class VTKWRAPPINGPYTHONCORE_EXPORT vtkSmartPyObject {
public:
  // Description:
  // Creates a new vtkSmartPyObject managing the existing reference
  // to the object given
  vtkSmartPyObject(PyObject *obj = NULL);
  // Description:
  // Creates a new vtkSmartPyObject to the object in the other smart
  // pointer and increments the reference count to the object
  vtkSmartPyObject(const vtkSmartPyObject &other);
  // Description:
  // Decrements the reference count to the object
  ~vtkSmartPyObject();

  // Description:
  // The internal pointer is copied from the other vtkSmartPyObject.
  // The reference count on the old object is decremented and the
  // reference count on the new object is incremented
  vtkSmartPyObject& operator=(const vtkSmartPyObject &other);
  // Description:
  // Sets the internal pointer to the given PyObject.  The reference
  // count on the PyObject is incremented.  To take a reference without
  // incrementing the reference count use TakeReference.
  vtkSmartPyObject& operator=(PyObject *obj);
  // Description:
  // Sets the internal pointer to the given PyObject without incrementing
  // the reference count
  void TakeReference(PyObject* obj);

  // Description:
  // Provides normal pointer target member access using operator ->.
  PyObject *operator->() const;
  // Description:
  // Get the contained pointer.
  operator PyObject*() const;

  // Description:
  // Returns true if the internal pointer is to a valid PyObject.
  operator bool() const;


  // Description:
  // Returns the pointer to a PyObject stored internally and clears the
  // internally stored pointer.  The caller is responsible for calling
  // Py_DECREF on the returned object when finished with it as this
  // does not change the reference count.
  PyObject* ReleaseReference();
  // Description:
  // Returns the internal pointer to a PyObject with no effect on its
  // reference count
  PyObject *GetPointer() const;
  // Description:
  // Returns the internal pointer to a PyObject and incrments its reference
  // count
  PyObject* GetAndIncreaseReferenceCount();
private:
  PyObject *Object;
};

#endif
