JUCE/src/gui/graphics/imaging/juce_ImageFileFormat.cpp

/*
  ==============================================================================

   This file is part of the JUCE library - "Jules' Utility Class Extensions"
   Copyright 2004-10 by Raw Material Software Ltd.

  ------------------------------------------------------------------------------

   JUCE can be redistributed and/or modified under the terms of the GNU General
   Public License (Version 2), as published by the Free Software Foundation.
   A copy of the license is included in the JUCE distribution, or can be found
   online at www.gnu.org/licenses.

   JUCE 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 General Public License for more details.

  ------------------------------------------------------------------------------

   To release a closed-source product which uses JUCE, commercial licenses are
   available: visit www.rawmaterialsoftware.com/juce for more information.

  ==============================================================================
*/

#include "../../../core/juce_StandardHeader.h"

BEGIN_JUCE_NAMESPACE

#include "juce_ImageFileFormat.h"
#include "../../../io/streams/juce_MemoryInputStream.h"
#include "../../../io/files/juce_FileInputStream.h"
#include "../../../io/streams/juce_BufferedInputStream.h"
#include "image_file_formats/juce_GIFLoader.h"


//==============================================================================
class GIFImageFormat  : public ImageFileFormat
{
public:
    GIFImageFormat()    {}
    ~GIFImageFormat()   {}

    const String getFormatName()
    {
        return "GIF";
    }

    bool canUnderstand (InputStream& in)
    {
        const int bytesNeeded = 4;
        char header [bytesNeeded];

        return (in.read (header, bytesNeeded) == bytesNeeded)
                && header[0] == 'G'
                && header[1] == 'I'
                && header[2] == 'F';
    }

    const Image decodeImage (InputStream& in)
    {
        const ScopedPointer <GIFLoader> loader (new GIFLoader (in));
        return loader->getImage();
    }

    bool writeImageToStream (const Image& /*sourceImage*/, OutputStream& /*destStream*/)
    {
        return false;
    }
};


//==============================================================================
ImageFileFormat* ImageFileFormat::findImageFormatForStream (InputStream& input)
{
    static PNGImageFormat png;
    static JPEGImageFormat jpg;
    static GIFImageFormat gif;

    ImageFileFormat* formats[4];
    int numFormats = 0;

    formats [numFormats++] = &png;
    formats [numFormats++] = &jpg;
    formats [numFormats++] = &gif;

    const int64 streamPos = input.getPosition();

    for (int i = 0; i < numFormats; ++i)
    {
        const bool found = formats[i]->canUnderstand (input);
        input.setPosition (streamPos);

        if (found)
            return formats[i];
    }

    return 0;
}

//==============================================================================
const Image ImageFileFormat::loadFrom (InputStream& input)
{
    ImageFileFormat* const format = findImageFormatForStream (input);

    if (format != 0)
        return format->decodeImage (input);

    return Image();
}

const Image ImageFileFormat::loadFrom (const File& file)
{
    InputStream* const in = file.createInputStream();

    if (in != 0)
    {
        BufferedInputStream b (in, 8192, true);
        return loadFrom (b);
    }

    return Image();
}

const Image ImageFileFormat::loadFrom (const void* rawData, const int numBytes)
{
    if (rawData != 0 && numBytes > 4)
    {
        MemoryInputStream stream (rawData, numBytes, false);
        return loadFrom (stream);
    }

    return Image();
}

END_JUCE_NAMESPACE