Method relativePath

kdevplatform/util/path.cpp:170–224

}

QString Path::relativePath(const Path& path) const
{
    if (!path.isValid()) {
        return QString();
    }
    if (!isValid() || remotePrefix() != path.remotePrefix()) {
        // different remote destinations or we are invalid, return input as-is
        return path.pathOrUrl();
    }
    // while I'd love to use QUrl::relativePath here, it seems to behave pretty
    // strangely, and adds unexpected "./" at the start for example
    // so instead, do it on our own based on _relativePath in kurl.cpp
    // this should also be more performant I think

    // Find where they meet
    int level = isRemote() ? 1 : 0;
    const int maxLevel = qMin(m_data.count(), path.m_data.count());
    while (level < maxLevel && m_data.at(level) == path.m_data.at(level)) {
        ++level;
    }

    // Need to go down out of our path to the common branch.
    // but keep in mind that e.g. '/' paths have an empty name
    int backwardSegments = m_data.count() - level;
    if (backwardSegments && level < maxLevel && m_data.at(level).isEmpty()) {
        --backwardSegments;
    }

    // Now up from the common branch to the second path.
    int forwardSegmentsLength = 0;
    for (int i = level; i < path.m_data.count(); ++i) {
        forwardSegmentsLength += path.m_data.at(i).length();
        // slashes
        if (i + 1 != path.m_data.count()) {
            forwardSegmentsLength += 1;
        }
    }

    QString relativePath;
    relativePath.reserve((backwardSegments * 3) + forwardSegmentsLength);
    for (int i = 0; i < backwardSegments; ++i) {
        relativePath.append(QLatin1String("../"));
    }

    for (int i = level; i < path.m_data.count(); ++i) {
        relativePath.append(path.m_data.at(i));
        if (i + 1 != path.m_data.count()) {
            relativePath.append(QLatin1Char('/'));
        }
    }

    Q_ASSERT(relativePath.length() == ((backwardSegments * 3) + forwardSegmentsLength));

    return relativePath;
}

static bool isParentPath(const QVector<QString>& parent, const QVector<QString>& child, bool direct)
{