mapnik/include/image_reader.hpp

/*****************************************************************************
 * 
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2006 Artem Pavlenko
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

//$Id: image_reader.hpp 39 2005-04-10 20:39:53Z pavlenko $

#ifndef IMAGE_READER_HPP
#define IMAGE_READER_HPP

#include "image_data.hpp"
#include <stdexcept>
#include <string>


namespace mapnik 
{
    class ImageReaderException : public std::exception
    {
    private:
	std::string message_;
    public:
	ImageReaderException(const std::string& message) 
	    : message_(message) {}

	~ImageReaderException() throw() {}

	virtual const char* what() const throw()
	{
	    return message_.c_str();
	}
    };

    struct ImageReader
    {
	virtual unsigned width() const=0;
	virtual unsigned height() const=0;
	virtual void read(unsigned x,unsigned y,ImageData32& image)=0;
	virtual ~ImageReader() {}
    };

    bool register_image_reader(const std::string& type,ImageReader* (*)(const std::string&));
    ImageReader* get_image_reader(const std::string& type,const std::string& file);
    
}

#endif                                            //IMAGE_READER_HPP