//===========================================================================//
// File:	iterator.hh                                                         //
// Project: MUNGA           Brick: Connection Library                        //
// Contents: Interface specifications for the abstract iterator              //
//---------------------------------------------------------------------------//
//   Date    Who  Modification                                               //
// --------  ---  ---------------------------------------------------------- //
// 10/19/94  ECH  Initial coding.                                            //
// 10/20/94  JMA  Fixed style stuff.                                         //
// 10/23/94  ECH  Added Begin, End, Forward, Backward style iteration		  //
//						methods																	  //
// 10/23/94  ECH  Added higher level of deletion safety							  //
// 10/28/94  JMA  Made compatible with SGI CC                                //
// 11/03/94  ECH  Made compatible with BC4.0                                 //
// 01/04/95  ECH  Added base methods for some iterator methods					  //
//---------------------------------------------------------------------------//
// Copyright (C) 1994-1995, Virtual World Entertainment, Inc.                //
// All Rights reserved worldwide                                             //
// This unpublished sourcecode is PROPRIETARY and CONFIDENTIAL               //
//===========================================================================//

#pragma once

#include "Stuff.hpp"

namespace Stuff {

	//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Iterator ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	class _declspec(novtable) Iterator
		#if defined(_ARMOR)
			: public Stuff::Signature
		#endif
	{
	public:
		//
		//--------------------------------------------------------------------
		//--------------------------------------------------------------------
		// Public interface to abstract class
		//
		// NOTE: All unsafe, untyped public methods are named XXXItem.  The
		// safe, typed public methods are named XXX and are declared in the
		// template sub-classes.
		//--------------------------------------------------------------------
		//--------------------------------------------------------------------
		//

		//
		//--------------------------------------------------------------------
		// Destructor and testing
		//--------------------------------------------------------------------
		//
		virtual
			~Iterator()
				{}
		virtual Iterator*
			MakeClone() = 0;
		void
			TestInstance()
				{}

		//
		//--------------------------------------------------------------------
		// First						- Moves to next item
		// Last						- Moves to last item
		//--------------------------------------------------------------------
		//
		virtual Iterator&
			First()=0;
		virtual Iterator&
			Last()=0;

		//
		//--------------------------------------------------------------------
		// Next			 			- Moves to next item
		// Previous			 		- Moves to previous item
		//--------------------------------------------------------------------
		//
		virtual Iterator&
			Next()=0;
		virtual Iterator&
			Previous()=0;

		//
		//--------------------------------------------------------------------
		// ReadAndNextItem		- Returns current item and moves to next item
		// ReadAndPreviousItem	- Returns current item and moves to prev item
		// GetCurrentItem			- Returns current item
		//--------------------------------------------------------------------
		//
		virtual void*
			GetCurrentItem()=0;
		virtual void*
			ReadAndNextItem()=0;
		virtual void*
			ReadAndPreviousItem()=0;

		virtual unsigned
			GetSize()=0;
		virtual void*
			GetNthItem(unsigned index)=0;

		Iterator&
			operator++()
				{return Next();}
		Iterator&
			operator--()
				{return Previous();}

	protected:
		//
		//--------------------------------------------------------------------
		//--------------------------------------------------------------------
		// Protected interface to abstract class
		//--------------------------------------------------------------------
		//--------------------------------------------------------------------
		//
		explicit Iterator()
			{}
	};

}