// -----------------------------------------------------------------------
// -                                                                     -
// -                      HDoubleList                                     -
// -                                                                     -
// -----------------------------------------------------------------------



#include <Standard_NoSuchObject.hxx>
#include <Standard_NotImplemented.hxx>

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// -                                                                     -
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// -                                                                     -
// -----------------------------------------------------------------------
PCollection_HDoubleList::PCollection_HDoubleList ( ){
}


// -----------------------------------------------------------------------
// -                                                                     -
// -                                                                     -
// -                                                                     -
// -----------------------------------------------------------------------
Handle(PCollection_HDoubleList) 
   PCollection_HDoubleList::Construct(const Item& T)
{

 Handle(PCollection_HDoubleList) me , L ;
 me = this;
 L  = new PCollection_HDoubleList;
 L->ChangeForwardPointer ( me );  // Pointeur avant de L sur me.
 Before = L;                      // Pointer arriere de me sur L.
 L->SetValue ( T );               // Mettre la valeur de l'item.
 return L;                        // C'est L qui est retourne.
}


// -----------------------------------------------------------------------
// -                                                                     -
// -                                                                     -
// -                                                                     -
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Handle(Standard_Persistent) PCollection_HDoubleList::ShallowCopy() const
{
  
  Handle(PCollection_HDoubleList) TheList,          // Traversal depth of <this>
                                TheCopy,          // The list returned
                                Pred,             // Backward pointer
                                Succ,             // Forward pointer
                                Last;             // Last cell

  TheCopy = new PCollection_HDoubleList;            // Initialization of the list
                                                  // that will be returned
  Standard_Boolean FirstTime = Standard_True;                 

  TheList = this;                                 // Start at the beginning
  Pred = Succ = TheCopy;
  
  while ( ! TheList->IsEmpty() ) {                // Append each item at the
    Succ = Succ->Construct(TheList->Value());     // end of the list
    if ( FirstTime ){
      FirstTime = Standard_False;
      TheCopy   = Succ;
    }
    else{
      Pred->ChangeForwardPointer(Succ);           // Make the link between 
      Succ->ChangeBackPointer(Pred);              // Pred and Succ
    }
    Pred = Succ;
    Succ = Succ->Tail();
    TheList = TheList->Tail();                   
  }
  return TheCopy;                                // Returns the header
}

// -----------------------------------------------------------------------
// -                                                                     -
// -                                                                     -
// -                                                                     -
// -----------------------------------------------------------------------
void PCollection_HDoubleList::ShallowDump(Standard_OStream& S) const
{
  Handle(PCollection_HDoubleList) TheList;
  TheList = this;
  S << "begin class HDoubleList " << endl;
  while ( ! TheList->IsEmpty() ) {                
    ::ShallowDump(TheList->Value(), S);
    TheList = TheList->Tail();
  }
  S << "end of HDoubleList." << endl;
}


/* Anciens INLINE */


void PCollection_HDoubleList::ChangeForwardPointer
   (const Handle(PCollection_HDoubleList)& L)
{
     Next = L;
}

void PCollection_HDoubleList::ChangeBackPointer
   (const Handle(PCollection_HDoubleList)& L)
{
    Before  = L;
}


void PCollection_HDoubleList::SetValue(const Item& T)
{
  Standard_NoSuchObject_Raise_if (IsEmpty(),
                                  "Empty Element in HDoubleList::SetValue");
  Data = T;
}


Item PCollection_HDoubleList::Value() const {
  Standard_NoSuchObject_Raise_if(IsEmpty(),
                                    "Empty Element in HDoubleList::Value");
  return Data;
}

Handle(PCollection_HDoubleList) PCollection_HDoubleList::Previous() const {
  Standard_NoSuchObject_Raise_if((IsEmpty() && Before.IsNull()),
                                 "Empty Element in HDoubleList::Previous");
  return Before;
}


Standard_Boolean PCollection_HDoubleList::IsEmpty()const
{
  return Next.IsNull();
}


Handle(PCollection_HDoubleList) PCollection_HDoubleList::Tail() const {
  Standard_NoSuchObject_Raise_if(IsEmpty(),
                                 "Empty Element in HDoubleList::Previous");
  return Next;
}

// -----------------------------------------------------------------------
// -                                                                     -
// -                                                                     -
// -                                                                     -
// -----------------------------------------------------------------------
void PCollection_HDoubleList::SwapTail(Handle(PCollection_HDoubleList)&
                                            WithList)
{
 // Exception si liste vide
  Standard_NoSuchObject_Raise_if(IsEmpty(),
                                 "Empty Element in HDoubleList::SwapTail") ;

  Handle(PCollection_HDoubleList) L  = Next;
  Handle(PCollection_HDoubleList) me ;
  me = this;
  WithList->ChangeBackPointer(me);
  Next = WithList;
  WithList = L;
}

void PCollection_HDoubleList::Destroy()
{
#ifdef CSFDB 
  Next.Nullify();
#endif
}