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/*************************************************************************
* Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com> *
* *
* This file is part of The Dimension Library. *
* *
* The Dimension 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 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension 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 program. If not, see *
* <http://www.gnu.org/licenses/>. *
*************************************************************************/
#ifndef DIMENSIONXX_PNG_HPP
#define DIMENSIONXX_PNG_HPP
// C++ wrapper for libdimension PNG support. PNG_Canvas derives from Canvas.
#include <istream>
#include <ostream>
namespace Dimension
{
// PNG_Canvas handles reading a Canvas from a PNG file, writing one to a PNG
// file, or both, depending on what type of stream(s) are given to the
// constructor.
class PNG_Canvas : public Canvas
{
public:
// Input PNG_Canvas; read the Canvas from istr now
explicit PNG_Canvas(std::istream& istr)
: Canvas(), m_istr(&istr), m_ostr(0), m_written(false) { read(); }
// Output PNG_Canvas; write the Canvas to ostr at destruction, or when
// write() is called.
PNG_Canvas(unsigned int x, unsigned int y, std::ostream& ostr)
: Canvas(x, y), m_istr(0), m_ostr(&ostr), m_written(false) { }
// I/O PNG_Canvas; read the Canvas from istr now, and write to ostr at
// destruction or then write() is called.
PNG_Canvas(std::istream& istr, std::ostream& ostr)
: Canvas(), m_istr(&istr), m_ostr(&ostr), m_written(false) { read(); }
// Call write() if we're an output PNG_Canvas, but trap any exceptions and
// report a dmnsn_error() instead.
virtual ~PNG_Canvas();
// Write the Canvas to the output stream, throwing a Dimension_Error on
// error.
void write();
protected:
// In case a derived class needs to set m_canvas after we're constructed
PNG_Canvas(std::ostream* ostr)
: Canvas(), m_istr(0), m_ostr(ostr), m_written(false) { }
private:
std::istream* m_istr;
std::ostream* m_ostr;
bool m_written;
// Read the Canvas from a PNG file, and throw a Dimension_Error upon
// failure.
void read();
// Copying prohibited
PNG_Canvas(const PNG_Canvas&);
PNG_Canvas& operator=(const PNG_Canvas&);
};
}
#endif /* DIMENSIONXX_PNG_HPP */
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