Carla/source/modules/juce_graphics/images/juce_ImageFileFormat.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

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

namespace juce
{

struct DefaultImageFormats
{
    static ImageFileFormat** get()
    {
        static DefaultImageFormats formats;
        return formats.formats;
    }

private:
    DefaultImageFormats() noexcept
    {
        formats[0] = &png;
        formats[1] = &jpg;
        formats[2] = &gif;
        formats[3] = nullptr;
    }

    PNGImageFormat  png;
    JPEGImageFormat jpg;
    GIFImageFormat  gif;

    ImageFileFormat* formats[4];
};

ImageFileFormat* ImageFileFormat::findImageFormatForStream (InputStream& input)
{
    const int64 streamPos = input.getPosition();

    for (ImageFileFormat** i = DefaultImageFormats::get(); *i != nullptr; ++i)
    {
        const bool found = (*i)->canUnderstand (input);
        input.setPosition (streamPos);

        if (found)
            return *i;
    }

    return nullptr;
}

ImageFileFormat* ImageFileFormat::findImageFormatForFileExtension (const File& file)
{
    for (ImageFileFormat** i = DefaultImageFormats::get(); *i != nullptr; ++i)
        if ((*i)->usesFileExtension (file))
            return *i;

    return nullptr;
}

//==============================================================================
Image ImageFileFormat::loadFrom (InputStream& input)
{
    if (ImageFileFormat* format = findImageFormatForStream (input))
        return format->decodeImage (input);

    return Image();
}

Image ImageFileFormat::loadFrom (const File& file)
{
    FileInputStream stream (file);

    if (stream.openedOk())
    {
        BufferedInputStream b (stream, 8192);
        return loadFrom (b);
    }

    return Image();
}

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

    return Image();
}

} // namespace juce