// Created by: DAUTRY Philippe
// Copyright (c) 1997-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

//      	--------------------------

// Version:	0.0
// Version	Date		Purpose
//		0.0	Feb  7 1997	Creation

#include <TDF_AttributeIterator.hxx>

//=================================================================================================

TDF_AttributeIterator::TDF_AttributeIterator()
    : myValue(0L),
      myWithoutForgotten(Standard_True)
{
}

//=================================================================================================

TDF_AttributeIterator::TDF_AttributeIterator(const TDF_Label&       aLabel,
                                             const Standard_Boolean withoutForgotten)
    : myValue(0L),
      myWithoutForgotten(withoutForgotten)
{
  const Handle(TDF_Attribute)& aFirstAttribute = aLabel.myLabelNode->FirstAttribute();
  if (!aFirstAttribute.IsNull())
    goToNext(aFirstAttribute);
}

//=================================================================================================

TDF_AttributeIterator::TDF_AttributeIterator(const TDF_LabelNodePtr aLabelNode,
                                             const Standard_Boolean withoutForgotten)
    : myValue(0L),
      myWithoutForgotten(withoutForgotten)
{
  const Handle(TDF_Attribute)& aFirstAttribute = aLabelNode->FirstAttribute();
  if (!aFirstAttribute.IsNull())
    goToNext(aFirstAttribute);
}

//=================================================================================================

void TDF_AttributeIterator::Initialize(const TDF_Label&       aLabel,
                                       const Standard_Boolean withoutForgotten)
{
  myWithoutForgotten                           = withoutForgotten;
  const Handle(TDF_Attribute)& aFirstAttribute = aLabel.myLabelNode->FirstAttribute();
  if (aFirstAttribute.IsNull())
    myValue = 0L;
  else
    goToNext(aFirstAttribute);
}

//=================================================================================================

void TDF_AttributeIterator::Next()
{
  // A little bit complicated...
  // but necessary if we want to find sometimes the Forgotten attributes.
  if (myValue)
  {
    const Handle(TDF_Attribute)& anAttribute = myValue->myNext;
    if (anAttribute.IsNull())
      myValue = 0L;
    else
      goToNext(anAttribute);
  }
}

//=======================================================================
// function : goToNext
// purpose  : private method, used by the above
//=======================================================================

void TDF_AttributeIterator::goToNext(const Handle(TDF_Attribute)& anAttr)
{
  myValue = anAttr.operator->();
  if (myWithoutForgotten)
  {
    while (myValue->IsForgotten())
    {
      const Handle(TDF_Attribute)& anAttribute = myValue->myNext;
      if (anAttribute.IsNull())
      {
        myValue = 0L;
        break;
      }
      myValue = anAttribute.operator->();
    }
  }
}