Method getRelativePathFrom

JUCE/modules/juce_core/files/juce_File.cpp:881–942

}

String File::getRelativePathFrom (const File& dir) const
{
    if (dir == *this)
        return ".";

    auto thisPath = fullPath;

    while (thisPath.endsWithChar (getSeparatorChar()))
        thisPath = thisPath.dropLastCharacters (1);

    auto dirPath = addTrailingSeparator (dir.existsAsFile() ? dir.getParentDirectory().getFullPathName()
                                                            : dir.fullPath);

    int commonBitLength = 0;
    auto thisPathAfterCommon = thisPath.getCharPointer();
    auto dirPathAfterCommon  = dirPath.getCharPointer();

    {
        auto thisPathIter = thisPath.getCharPointer();
        auto dirPathIter = dirPath.getCharPointer();

        for (int i = 0;;)
        {
            auto c1 = thisPathIter.getAndAdvance();
            auto c2 = dirPathIter.getAndAdvance();

           #if NAMES_ARE_CASE_SENSITIVE
            if (c1 != c2
           #else
            if ((c1 != c2 && CharacterFunctions::toLowerCase (c1) != CharacterFunctions::toLowerCase (c2))
           #endif
                 || c1 == 0)
                break;

            ++i;

            if (c1 == getSeparatorChar())
            {
                thisPathAfterCommon = thisPathIter;
                dirPathAfterCommon  = dirPathIter;
                commonBitLength = i;
            }
        }
    }

    // if the only common bit is the root, then just return the full path..
    if (commonBitLength == 0 || (commonBitLength == 1 && thisPath[1] == getSeparatorChar()))
        return fullPath;

    auto numUpDirectoriesNeeded = countNumberOfSeparators (dirPathAfterCommon);

    if (numUpDirectoriesNeeded == 0)
        return thisPathAfterCommon;

   #if JUCE_WINDOWS
    auto s = String::repeatedString ("..\\", numUpDirectoriesNeeded);
   #else
    auto s = String::repeatedString ("../",  numUpDirectoriesNeeded);