// File:      Poly_CoherentTriPtr.hxx
// Created:   08.12.07 11:52
// Author:    Alexander GRIGORIEV
// Copyright: Open Cascade 2007


#ifndef Poly_CoherentTriPtr_HeaderFile
#define Poly_CoherentTriPtr_HeaderFile

#include <NCollection_BaseAllocator.hxx>

class Poly_CoherentTriangle;

#ifdef WNT
#pragma warning (push)
#pragma warning(disable:4355 4291) //'this' : used in base member initializer list
#endif

/**
 * Implementation of both list node for Poly_CoherentTriangle type and
 * round double-linked list of these nodes. 
 */

class Poly_CoherentTriPtr
{
 public:
  /**
   * Iterator class for this list of triangles. Because the list is round,
   * an iteration can be started from any member and it finishes before taking
   * this member again. The iteration sense is always forward (Next).
   */  
  class Iterator {
  public:
    //! Empty constructor
    inline Iterator ()
      : myFirst         (0L),
        myCurrent       (0L)
    {}
    //! Constructor
    inline Iterator (const Poly_CoherentTriPtr& thePtr)
      : myFirst         (&thePtr),
        myCurrent       (&thePtr)
    {}
    //! Query the triangle that started the current iteration.
    inline const Poly_CoherentTriangle * First  () const
    { return myFirst ? &myFirst->GetTriangle() : 0L; }
    //! Query if there is available triangle pointer on this iteration
    inline Standard_Boolean             More    () const
    { return myCurrent != 0L; }
    //! Go to the next iteration.
    Standard_EXPORT void                Next    ();
    //! Get the current iterated triangle
    inline const Poly_CoherentTriangle& Value   () const
    { return myCurrent->GetTriangle(); }
    //! Get the current iterated triangle (mutable)
    inline Poly_CoherentTriangle&       ChangeValue   () const
    { return const_cast<Poly_CoherentTriangle&>(myCurrent->GetTriangle()); }
    //! Get the current iterated pointer to triangle
    inline const Poly_CoherentTriPtr&   PtrValue() const
    { return * myCurrent; }
  private:
    const Poly_CoherentTriPtr * myFirst;
    const Poly_CoherentTriPtr * myCurrent;
  };

  // ---------- PUBLIC METHODS ----------


  /**
   * Constructor.
   */
  inline Poly_CoherentTriPtr (const Poly_CoherentTriangle& theTri)
    : mypTriangle (&theTri),
      myNext      (this),
      myPrevious  (this)
  {}

  /**
   * Operator new for dynamic allocations
   */
  void* operator new    (Standard_Size theSize,
                         const Handle(NCollection_BaseAllocator)& theAllocator)
  {
    return theAllocator->Allocate(theSize);
  }

  void operator delete (void * aBuffer, const Handle(NCollection_BaseAllocator)& theAllocator) 
  {
    theAllocator->Free(aBuffer);
  };

  /**
   * Query the stored pointer to Triangle.
   */
  inline const Poly_CoherentTriangle&
                        GetTriangle () const
  { return * mypTriangle; }

  /**
   * Initialize this instance with a pointer to triangle.
   */
  inline void          SetTriangle (const Poly_CoherentTriangle * pTri)
  { mypTriangle = pTri; }
  
  /**
   * Query the next pointer in the list.
   */
  inline Poly_CoherentTriPtr&
                       Next     () const
  { return * myNext; }

  /**
   * Query the previous pointer in the list.
   */
  inline Poly_CoherentTriPtr&
                       Previous () const
  { return * myPrevious; }

  /**
   * Append a pointer to triangle into the list after the current instance.
   * @param pTri
   *   Triangle that is to be included in the list after this one.
   * @param theA
   *   Allocator where the new pointer instance is created.
   */
  Standard_EXPORT void Append   (const Poly_CoherentTriangle *           pTri,
                                 const Handle_NCollection_BaseAllocator& theA);

  /**
   * Prepend a pointer to triangle into the list before the current instance.
   * @param pTri
   *   Triangle that is to be included in the list before this one.
   * @param theA
   *   Allocator where the new pointer instance is created.
   */
  Standard_EXPORT void Prepend  (const Poly_CoherentTriangle *           pTri,
                                 const Handle_NCollection_BaseAllocator& theA);

  /**
   * Remove a pointer to triangle from its list.
   * @param thePtr
   *   This class instance that should be removed from its list.
   * @param theA
   *   Allocator where the current pointer instance was created.
   */
  Standard_EXPORT static void
                       Remove   (Poly_CoherentTriPtr *                   thePtr,
                                 const Handle_NCollection_BaseAllocator& theA);

  /**
   * Remove the list containing the given pointer to triangle.
   */
  Standard_EXPORT static void
                       RemoveList (Poly_CoherentTriPtr *                 thePtr,
                                   const Handle_NCollection_BaseAllocator&);

 protected:
  // ---------- PROTECTED METHODS ----------

  /**
   * Constructor.
   */
  inline Poly_CoherentTriPtr (const Poly_CoherentTriangle * pTri)
    : mypTriangle (pTri),
      myNext      (this),
      myPrevious  (this)
  {}

 private:
  // ---------- PRIVATE FIELDS ----------

  const Poly_CoherentTriangle * mypTriangle;
  Poly_CoherentTriPtr         * myNext;
  Poly_CoherentTriPtr         * myPrevious;

  friend class Iterator;
};

#ifdef WNT
#pragma warning (pop)
#endif

#endif