sequence.cpp

barcode readers [ from Image]

//
// CSequence
//   Implements a sequence of pipeline stages as described in the header file.
//
// Copyright (C) 2003, 2006 by Jon A. Webb (Contact via GMail; username is jonawebb)
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//


#include "sequence.h"

namespace Core
{
	EXPORT_C CSequence* CSequence::NewL(MPipelineStage* pPipe)
	{
		return new (ELeave) CSequence(pPipe);
	}

	CSequence::CSequence(MPipelineStage* pPipe) :
		iPipe1(pPipe),
		iPipe2(NULL)
	{
	}

	CSequence::~CSequence(void)
	{
		delete iPipe1;
		delete iPipe2;
	}

	void CSequence::AddL(MPipelineStage* pPipe)
	{
		ASSERT(pPipe);
		if (iPipe2 == NULL) {
			// We are the last CSequence in the pipeline
			iPipe2 = NewL(pPipe);
		} else {
			// We are not the last, pass the new pipeline stage on
			// recursively
			iPipe2->AddL(pPipe);
		}
	}

	CImage CSequence::FrontL() 
	{
		if (iPipe2 != NULL) {
			return iPipe2->FrontL();
		} else {
			return iPipe1->FrontL();
		}
	}

	void CSequence::PushL(CImage pImage)
	{
		iPipe1->PushL(pImage);
		if (iPipe2 != NULL) {
			while (!iPipe1->Empty()) {
				iPipe2->PushL(iPipe1->FrontL());
			}
		}
	}

	bool CSequence::Empty() const
	{
		if (iPipe2 != NULL) {
			return iPipe2->Empty();
		} else {
			return iPipe1->Empty();
		}
	}
};