/////////////////////////////////////////////////////////////////////////////// 
// Copyright (C) 2002-2025, Open Design Alliance (the "Alliance"). 
// All rights reserved. 
// 
// This software and its documentation and related materials are owned by 
// the Alliance. The software may only be incorporated into application 
// programs owned by members of the Alliance, subject to a signed 
// Membership Agreement and Supplemental Software License Agreement with the
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// trade secrets of the Alliance and its suppliers. The software is also 
// protected by copyright law and international treaty provisions. Application  
// programs incorporating this software must include the following statement 
// with their copyright notices:
//   
//   This application incorporates Open Design Alliance software pursuant to a license 
//   agreement with Open Design Alliance.
//   Open Design Alliance Copyright (C) 2002-2025 by Open Design Alliance. 
//   All rights reserved.
//
// By use of this software, its documentation or related materials, you 
// acknowledge and accept the above terms.
///////////////////////////////////////////////////////////////////////////////

#ifndef _ODSAVESTATE_INCLUDED_
#define _ODSAVESTATE_INCLUDED_

#include "TD_PackPush.h"

/** \details
    This template class implements SaveState objects which save and restore variables.

    \remarks
    Variables are saved locally on construction of OdSaveState objects.
    Variables are restored when OdSaveState objects go out of scope.

    <group Other_Classes>
*/
template <class T>
class OdSaveState
{
  T&  m_val;        // Variable
  T   m_oldValue;   // Old value
public:

  /** \details
    Constructor for objects of the OdSaveState class. Saves a variable without
    assigning it a new value.

    \param variable [in]  Variable to save.
  */
  OdSaveState( T& variable )
    : m_val( variable )
  {
    m_oldValue = m_val;
  }
  
  /** \details
    Constructor for objects of the OdSaveState class. Saves a variable and
    assigns it a new value.

    \param variable [in]  Variable to save.
    \param newValue [in]  New value for a variable.
  */
  OdSaveState( T& variable, const T& newValue )
    : m_val( variable )
  {
    m_oldValue = m_val;
    m_val = newValue;
  }

  /** \details
    Destructor for objects of the OdSaveState class. Restores the old value of
    a variable.
  */
  ~OdSaveState()
  {
    m_val = m_oldValue;
  }

  /** \details
    Returns the saved value of the variable.
  */
  operator const T&() const
  {
    return m_oldValue;
  }
};

#ifdef __hpux
#define OdSaveStateFlagDef(type, flag, name, flags) \
  const type _##name##Flag = flag; \
  OdSaveStateFlagImpl<type, _##name##Flag> name(flags)
#define OdSaveStateFlag(type, flag, name, flags, newVal) \
  const type _##name##Flag = flag; \
  OdSaveStateFlagImpl<type, _##name##Flag> name(flags, newVal)
#else
#define OdSaveStateFlagDef(type, flag, name, flags) \
  OdSaveStateFlagImpl<type, flag> name(flags)
#define OdSaveStateFlag(type, flag, name, flags, newVal) \
  OdSaveStateFlagImpl<type, flag> name(flags, newVal)
#endif

/** \details
  This template class implements SaveState objects which save and restore flags.

  <group Other_Classes> 
*/
template <class T, T flag>
class OdSaveStateFlagImpl
{
  T&   m_val;       // Current flag value
  bool m_oldValue;  // Old flag value
public:

  /** \details
    Constructor for objects of the OdSaveStateFlagImpl class. Saves a flag without
    assigning it a new value.

    \param variable [in]  Flag to save.
  */
  OdSaveStateFlagImpl(T& variable): m_val( variable )
  {
    m_oldValue = GETBIT(m_val, flag);
  }

  /** \details
    Constructor for objects of the OdSaveStateFlagImpl class. Saves a flag and
    assigns it a new value.

    \param variable [in]  Flag to save.
    \param newValue [in]  New value for a flag.
  */
  OdSaveStateFlagImpl(T& variable, bool bNewValue): m_val( variable )
  {
    m_oldValue = GETBIT(m_val, flag);
    SETBIT(m_val, flag, bNewValue);
  }

  /** \details
    Destructor for objects of the OdSaveStateFlagImpl class. Restores the old value of
    a flag.
  */
  ~OdSaveStateFlagImpl()
  {
    SETBIT(m_val, flag, m_oldValue);
  }

  /** \details
    Returns the saved value of the flag.
  */
  operator bool() const
  {
    return m_oldValue;
  }
};

/** \details
    This template class implements SaveState objects which save and restore flags mask.

    \remarks
    Flags saved locally on construction of OdSaveState objects.
    Flags restored when OdSaveState objects go out of scope.

    <group Other_Classes>
*/
template <class T, T flagsMask>
class OdSaveStateFlagsMask
{
  T &m_val, m_oldValue;
public:
  /** \details
    Constructor for objects of the OdSaveStateFlagsMask class. Saves flags without
    assigning it a new value.

    \param variable [in]  Variable to save.
  */
  OdSaveStateFlagsMask( T& variable )
    : m_val(variable), m_oldValue(variable & flagsMask)
  { }

  /** \details
    Constructor for objects of the OdSaveStateFlagsMask class. Saves flags and
    assigns them a new value.

    \param variable [in]  Variable to save.
    \param newValue [in]  New value for flags.
  */
  OdSaveStateFlagsMask( T& variable, const T& newValue )
    : m_val(variable), m_oldValue(variable & flagsMask)
  { variable = (variable & ~flagsMask) | newValue; }

  /** \details
    Destructor for objects of the OdSaveState class. Restores the old value of
    a variable.
  */
  ~OdSaveStateFlagsMask()
  {
    m_val = (m_val & ~flagsMask) | m_oldValue;
  }

  /** \details
    Returns the saved flags of the variable.
  */
  operator const T&() const
  {
    return m_oldValue;
  }
};

/** \details
  This template class implements SaveState objects which save and restore functions.

  <group Other_Classes> 
*/
template <typename ObjType, typename ValType>
class OdSaveStateFunc
{
public:
  /** \details
    Constructor for objects of the OdSaveStateFunc class.
  */
  OdSaveStateFunc(ObjType* pObj, ValType(ObjType::*getFunc)() const,
    void(ObjType::*setFunc)(ValType))
    :m_pObj(pObj), m_getFunc(getFunc), m_setFunc(setFunc)
  {
    m_oldValue = (*m_pObj.*m_getFunc)();
  }

  /** \details
    Constructor for objects of the OdSaveStateFunc class.
  */
  OdSaveStateFunc(ObjType* pObj, ValType(ObjType::*getFunc)() const,
    void(ObjType::*setFunc)(ValType), ValType newValue)
    :m_pObj(pObj), m_getFunc(getFunc), m_setFunc(setFunc)
  {
    m_oldValue = (*m_pObj.*m_getFunc)();
    (*m_pObj.*m_setFunc)(newValue);
  }

  /** \details
    Destructor for objects of the OdSaveStateFunc class. Restores the old value
    of a function.
  */
  ~OdSaveStateFunc()
  {
    (*m_pObj.*m_setFunc)(m_oldValue);
  }
protected:
  ObjType* m_pObj;
  ValType(ObjType::*m_getFunc)() const;
  void(ObjType::*m_setFunc)(ValType);
  ValType m_oldValue;
};

#include "TD_PackPop.h"

#endif //#ifndef _ODSAVESTATE_INCLUDED_