JUCE/modules/juce_graphics/native/juce_mac_IconHelpers.cpp

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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

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

   For the technical preview this file cannot be licensed commercially.

   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
{

extern Image JUCE_API getIconFromApplication (const String&, int);

static Image getIconFromIcnsFile (const File& icnsFile, const int size)
{
    FileInputStream stream (icnsFile);

    if (! stream.openedOk())
        return {};

    const int numHeaderSectionBytes = 4;
    char headerSection [numHeaderSectionBytes];

    if (stream.read (headerSection, numHeaderSectionBytes) != numHeaderSectionBytes
          || headerSection[0] != 'i'
          || headerSection[1] != 'c'
          || headerSection[2] != 'n'
          || headerSection[3] != 's')
        return {};

    if (stream.read (headerSection, numHeaderSectionBytes) != numHeaderSectionBytes)
        return {};

    const auto dataSize = juce::ByteOrder::bigEndianInt (headerSection);

    if (dataSize <= 0)
        return {};

    OwnedArray<juce::ImageFileFormat> internalFormats;
    internalFormats.add (new  PNGImageFormat());
    internalFormats.add (new JPEGImageFormat());

    Array<Image> images;
    auto maxWidth = 0;
    auto maxWidthIndex = -1;

    while (stream.getPosition() < dataSize)
    {
        const auto sectionStart = stream.getPosition();

        if (! stream.setPosition (sectionStart + 4))
            break;

        if (stream.read (headerSection, numHeaderSectionBytes) != numHeaderSectionBytes)
            break;

        const auto sectionSize = ByteOrder::bigEndianInt (headerSection);

        if (sectionSize <= 0)
            break;

        const auto sectionDataStart = stream.getPosition();

        for (auto* fmt : internalFormats)
        {
            if (fmt->canUnderstand (stream))
            {
                stream.setPosition (sectionDataStart);

                images.add (fmt->decodeImage (stream));

                const auto lastImageIndex = images.size() - 1;
                const auto lastWidth = images.getReference (lastImageIndex).getWidth();

                if (lastWidth > maxWidth)
                {
                    maxWidthIndex = lastImageIndex;
                    maxWidth = lastWidth;
                }
            }

            stream.setPosition (sectionDataStart);
        }

        stream.setPosition (sectionStart + sectionSize);
    }

    return maxWidthIndex == -1 ? juce::Image()
                               : images.getReference (maxWidthIndex).rescaled (size, size, Graphics::ResamplingQuality::highResamplingQuality);
}

Image JUCE_API getIconFromApplication (const String& applicationPath, const int size)
{
    if (auto pathCFString = CFUniquePtr<CFStringRef> (CFStringCreateWithCString (kCFAllocatorDefault, applicationPath.toRawUTF8(), kCFStringEncodingUTF8)))
    {
        if (auto url = CFUniquePtr<CFURLRef> (CFURLCreateWithFileSystemPath (kCFAllocatorDefault, pathCFString.get(), kCFURLPOSIXPathStyle, 1)))
        {
            if (auto appBundle = CFUniquePtr<CFBundleRef> (CFBundleCreate (kCFAllocatorDefault, url.get())))
            {
                if (CFTypeRef infoValue = CFBundleGetValueForInfoDictionaryKey (appBundle.get(), CFSTR("CFBundleIconFile")))
                {
                    if (CFGetTypeID (infoValue) == CFStringGetTypeID())
                    {
                        CFStringRef iconFilename = reinterpret_cast<CFStringRef> (infoValue);
                        CFStringRef resourceURLSuffix = CFStringHasSuffix (iconFilename, CFSTR(".icns")) ? nullptr : CFSTR("icns");

                        if (auto iconURL = CFUniquePtr<CFURLRef> (CFBundleCopyResourceURL (appBundle.get(), iconFilename, resourceURLSuffix, nullptr)))
                        {
                            if (auto iconPath = CFUniquePtr<CFStringRef> (CFURLCopyFileSystemPath (iconURL.get(), kCFURLPOSIXPathStyle)))
                            {
                                File icnsFile (CFStringGetCStringPtr (iconPath.get(), CFStringGetSystemEncoding()));
                                return getIconFromIcnsFile (icnsFile, size);
                            }
                        }
                    }
                }
            }
        }
    }

    return {};
}

} // namespace juce