qdir.cpp

QT 开发环境里面一个很重要的文件

    Returns true if successful; otherwise returns false.

    \sa mkdir()
*/

bool QDir::rmdir(const QString &dirName) const
{
    Q_D(const QDir);

    if (dirName.isEmpty()) {
        qWarning("QDir::rmdir: Empty or null file name(s)");
        return false;
    }
    if(!d->data->fileEngine)
        return false;

    QString fn = filePath(dirName);
    return d->data->fileEngine->rmdir(fn, false);
}

/*!
    Creates the directory path \a dirPath.

    The function will create all parent directories necessary to
    create the directory.

    Returns true if successful; otherwise returns false.

    \sa rmpath()
*/

bool QDir::mkpath(const QString &dirPath) const
{
    Q_D(const QDir);

    if (dirPath.isEmpty()) {
        qWarning("QDir::mkpath: Empty or null file name(s)");
        return false;
    }
    if(!d->data->fileEngine)
        return false;

    QString fn = filePath(dirPath);
    return d->data->fileEngine->mkdir(fn, true);
}

/*!
    Removes the directory path \a dirPath.

    The function will remove all parent directories in \a dirPath,
    provided that they are empty. This is the opposite of
    mkpath(dirPath).

    Returns true if successful; otherwise returns false.

    \sa mkpath()
*/
bool QDir::rmpath(const QString &dirPath) const
{
    Q_D(const QDir);

    if (dirPath.isEmpty()) {
        qWarning("QDir::rmpath: Empty or null file name(s)");
        return false;
    }
    if(!d->data->fileEngine)
        return false;

    QString fn = filePath(dirPath);
    return d->data->fileEngine->rmdir(fn, true);
}

/*!
    Returns true if the directory is readable \e and we can open files
    by name; otherwise returns false.

    \warning A false value from this function is not a guarantee that
    files in the directory are not accessible.

    \sa QFileInfo::isReadable()
*/


bool QDir::isReadable() const
{
    Q_D(const QDir);

    if(!d->data->fileEngine)
        return false;
    const QAbstractFileEngine::FileFlags info = d->data->fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
                                                                       |QAbstractFileEngine::PermsMask);
    if(!(info & QAbstractFileEngine::DirectoryType))
        return false;
    return info & QAbstractFileEngine::ReadUserPerm;
}

/*!
    \overload

    Returns true if the \e directory exists; otherwise returns false.
    (If a file with the same name is found this function will return
    false).

    \sa QFileInfo::exists(), QFile::exists()
*/

bool QDir::exists() const
{
    Q_D(const QDir);

    if(!d->data->fileEngine)
        return false;
    const QAbstractFileEngine::FileFlags info = d->data->fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
                                                                       |QAbstractFileEngine::ExistsFlag);
    if(!(info & QAbstractFileEngine::DirectoryType))
        return false;
    return info & QAbstractFileEngine::ExistsFlag;
}

/*!
    Returns true if the directory is the root directory; otherwise
    returns false.

    Note: If the directory is a symbolic link to the root directory
    this function returns false. If you want to test for this use
    canonicalPath(), e.g.

    \code
        QDir dir("/tmp/root_link");
        dir = dir.canonicalPath();
        if (dir.isRoot())
            qWarning("It is a root link");
    \endcode

    \sa root(), rootPath()
*/

bool QDir::isRoot() const
{
    Q_D(const QDir);

    if(!d->data->fileEngine)
        return true;
    return d->data->fileEngine->fileFlags(QAbstractFileEngine::FlagsMask) & QAbstractFileEngine::RootFlag;
}

/*!
    \fn bool QDir::isAbsolute() const

    Returns true if the directory's path is absolute; otherwise
    returns false. See isAbsolutePath().

    \sa isRelative() makeAbsolute() cleanPath()
*/

/*!
   \fn bool QDir::isAbsolutePath(const QString &)

    Returns true if \a path is absolute; returns false if it is
    relative.

    \sa isAbsolute() isRelativePath() makeAbsolute() cleanPath()
*/

/*!
    Returns true if the directory path is relative; otherwise returns
    false. (Under Unix a path is relative if it does not start with a
    "/").

    \sa makeAbsolute() isAbsolute() isAbsolutePath() cleanPath()
*/

bool QDir::isRelative() const
{
    Q_D(const QDir);

    if(!d->data->fileEngine)
        return false;
    return d->data->fileEngine->isRelativePath();
}


/*!
    Converts the directory path to an absolute path. If it is already
    absolute nothing happens. Returns true if the conversion
    succeeded; otherwise returns false.

    \sa isAbsolute() isAbsolutePath() isRelative() cleanPath()
*/

bool QDir::makeAbsolute() // ### What do the return values signify?
{
    Q_D(QDir);

    if(!d->data->fileEngine)
        return false;
    QString absolutePath = d->data->fileEngine->fileName(QAbstractFileEngine::AbsoluteName);
    if(QDir::isRelativePath(absolutePath))
        return false;
    d->detach();
    d->data->path = absolutePath;
    d->data->fileEngine->setFileName(absolutePath);
    if(!(d->data->fileEngine->fileFlags(QAbstractFileEngine::TypesMask) & QAbstractFileEngine::DirectoryType))
        return false;
    return true;
}

/*!
    Returns true if directory \a dir and this directory have the same
    path and their sort and filter settings are the same; otherwise
    returns false.

    Example:

    \code
        // The current directory is "/usr/local"
        QDir d1("/usr/local/bin");
        QDir d2("bin");
        if (d1 == d2)
            qDebug("They're the same");
    \endcode
*/

bool QDir::operator==(const QDir &dir) const
{
    const QDirPrivate *d = d_func();
    const QDirPrivate *other = dir.d_func();

    if(d->data == other->data)
        return true;
    Q_ASSERT(d->data->fileEngine && other->data->fileEngine);
    if(d->data->fileEngine->caseSensitive() != other->data->fileEngine->caseSensitive())
        return false;
    if(d->data->filters == other->data->filters
       && d->data->sort == other->data->sort
       && d->data->nameFilters == other->data->nameFilters) {
        QString dir1 = absolutePath(), dir2 = dir.absolutePath();
        if(!other->data->fileEngine->caseSensitive())
            return (dir1.toLower() == dir2.toLower());

        return (dir1 == dir2);

    }
    return false;
}

/*!
    Makes a copy of the \a dir object and assigns it to this QDir
    object.
*/

QDir &QDir::operator=(const QDir &dir)
{
    if (this == &dir)
        return *this;

    Q_D(QDir);
    qAtomicAssign(d->data, dir.d_func()->data);
    return *this;
}

/*!
    \overload
    \obsolete

    Sets the directory path to the given \a path.

    Use setPath() instead.
*/

QDir &QDir::operator=(const QString &path)
{
    Q_D(QDir);

    d->setPath(path);
    return *this;
}

/*!
    \fn bool QDir::operator!=(const QDir &dir) const

    Returns true if directory \a dir and this directory have different
    paths or different sort or filter settings; otherwise returns
    false.

    Example:

    \code
        // The current directory is "/usr/local"
        QDir d1("/usr/local/bin");
        QDir d2("bin");
        if (d1 != d2)
            qDebug("They differ");
    \endcode
*/


/*!
    Removes the file, \a fileName.

    Returns true if the file is removed successfully; otherwise
    returns false.
*/

bool QDir::remove(const QString &fileName)
{
    if (fileName.isEmpty()) {
        qWarning("QDir::remove: Empty or null file name");
        return false;
    }
    QString p = filePath(fileName);
    return QFile::remove(p);
}

/*!
    Renames a file or directory from \a oldName to \a newName, and returns
    true if successful; otherwise returns false.

    On most file systems, rename() fails only if \a oldName does not
    exist, if \a newName and \a oldName are not on the same
    partition or if a file with the new name already exists.
    However, there are also other reasons why rename() can
    fail. For example, on at least one file system rename() fails if
    \a newName points to an open file.
*/

bool QDir::rename(const QString &oldName, const QString &newName)
{
    Q_D(QDir);

    if (oldName.isEmpty() || newName.isEmpty()) {
        qWarning("QDir::rename: Empty or null file name(s)");
        return false;
    }
    if(!d->data->fileEngine)
        return false;

    QFile file(filePath(oldName));
    if(!file.exists())
        return false;
    return file.rename(filePath(newName));
}

/*!
    Returns true if the file called \a name exists; otherwise returns
    false.

    \sa QFileInfo::exists(), QFile::exists()
*/

bool QDir::exists(const QString &name) const
{
    if (name.isEmpty()) {
        qWarning("QDir::exists: Empty or null file name");
        return false;
    }
    QString tmp = filePath(name);
    return QFile::exists(tmp);
}

/*!
    Returns a list of the root directories on this system.

    On Windows this returns a list of QFileInfo objects containing "C:/",
    "D:/", etc. On other operating systems, it returns a list containing
    just one root directory (i.e. "/").

    \sa root(), rootPath()
*/

QFileInfoList QDir::drives()
{
    return QFSFileEngine::drives();
}

/*!
    Returns the native directory separator: "/" under Unix (including
    Mac OS X) and "\\" under Windows.

    You do not need to use this function to build file paths. If you
    always use "/", Qt will translate your paths to conform to the
    underlying operating system. If you want to display paths to the
    user using their operating system's separator use
    toNativeSeparators().
*/

QChar QDir::separator()
{
#if defined(Q_OS_UNIX)
    return QLatin1Char('/');
#elif defined (Q_FS_FAT) || defined(Q_WS_WIN)
    return QLatin1Char('\\');
#elif defined (Q_OS_MAC)
    return QLatin1Char(':');
#else
    return QLatin1Char('/');
#endif
}

/*!
    Sets the application's current working directory to \a path.
    Returns true if the directory was successfully changed; otherwise
    returns false.

    \sa current() currentPath() home() root() temp()
*/

bool QDir::setCurrent(const QString &path)
{
    return QFSFileEngine::setCurrentPath(path);
}

/*!
    \fn QDir QDir::current()

    Returns the application's current directory.

    The directory is constructed using the absolute path of the current directory,
    ensuring that its path() will be the same as its absolutePath().

    \sa currentPath(), home(), root(), temp()
*/

/*!
    Returns the absolute path of the application's current directory.

    \sa current(), homePath(), rootPath(), tempPath()
*/

QString QDir::currentPath()
{
    return QFSFileEngine::currentPath();
}

/*!
    \fn QDir QDir::home()

    Returns the user's home directory.

    The directory is constructed using the absolute path of the home directory,
    ensuring that its path() will be the same as its absolutePath().

    See homePath() for details.

    \sa drives(), current(), root(), temp()
*/

/*!
    Returns the absolute path of the user's home directory.

    Under Windows this function will return the directory of the
    current user's profile. Typically, this is:

    \code
        C:\Documents and Settings\Username
    \endcode