qcoreapplication.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    \code
        foreach (QString path, app.libraryPaths())
            do_something(path);
    \endcode

    \sa setLibraryPaths(), addLibraryPath(), removeLibraryPath(), QLibrary,
        {How to Create Qt Plugins}
*/
QStringList QCoreApplication::libraryPaths()
{
    QMutexLocker locker(libraryPathMutex());
    if (!self)
        return QStringList();
    if (!coreappdata()->app_libpaths) {
        QStringList *app_libpaths = coreappdata()->app_libpaths = new QStringList;
        QString installPathPlugins =  QLibraryInfo::location(QLibraryInfo::PluginsPath);
        if (QFile::exists(installPathPlugins)) {
            // Make sure we convert from backslashes to slashes.
            installPathPlugins = QDir(installPathPlugins).canonicalPath();
            app_libpaths->append(installPathPlugins);
        }

        // If QCoreApplication is not yet instantiated,
        // make sure we add the application path when we construct the QCoreApplication
        if (self) self->d_func()->appendApplicationPathToLibraryPaths();

        const QByteArray libPathEnv = qgetenv("QT_PLUGIN_PATH");
        if (!libPathEnv.isEmpty()) {
#ifdef Q_OS_WIN
            QChar pathSep(';');
#else
            QChar pathSep(':');
#endif
            QStringList paths = QString::fromLatin1(libPathEnv).split(pathSep, QString::SkipEmptyParts);
            for (QStringList::iterator it = paths.begin(); it != paths.end(); ++it) {
                app_libpaths->append(QDir(*it).canonicalPath());
            }
        }
    }
    return *(coreappdata()->app_libpaths);
}



/*!
  Sets the list of directories to search when loading libraries to \a paths.
  All existing paths will be deleted and the path list will consist of the
  paths given in \a paths.

  \sa libraryPaths(), addLibraryPath(), removeLibraryPath(), QLibrary
 */
void QCoreApplication::setLibraryPaths(const QStringList &paths)
{
    *(coreappdata()->app_libpaths) = paths;
}
/*!
  Appends \a path to the end of the library path list. If \a path is
  empty or already in the path list, the path list is not changed.

  The default path list consists of a single entry, the installation
  directory for plugins.  The default installation directory for plugins
  is \c INSTALL/plugins, where \c INSTALL is the directory where Qt was
  installed.

  \sa removeLibraryPath(), libraryPaths(), setLibraryPaths()
 */
void QCoreApplication::addLibraryPath(const QString &path)
{
    if (path.isEmpty())
        return;

    // make sure that library paths is initialized
    libraryPaths();

    QString canonicalPath = QDir(path).canonicalPath();
    if (!coreappdata()->app_libpaths->contains(canonicalPath))
        coreappdata()->app_libpaths->prepend(canonicalPath);
}

/*!
    Removes \a path from the library path list. If \a path is empty or not
    in the path list, the list is not changed.

    \sa addLibraryPath(), libraryPaths(), setLibraryPaths()
*/
void QCoreApplication::removeLibraryPath(const QString &path)
{
    if (path.isEmpty())
        return;

    // make sure that library paths is initialized
    libraryPaths();

    coreappdata()->app_libpaths->removeAll(path);
}

#endif //QT_NO_LIBRARY

/*!
    \typedef QCoreApplication::EventFilter

    A function with the following signature that can be used as an
    event filter:

    \code
        bool myEventFilter(void *message, long *result);
    \endcode

    \sa setEventFilter()
*/

/*!
    \fn EventFilter QCoreApplication::setEventFilter(EventFilter filter)

    Sets the event filter \a filter. Returns a pointer to the filter
    function previously defined.

    The event filter is a function that is called for every message
    received in all threads. This does \e not include messages to
    objects that are not handled by Qt.

    The function can return true to stop the event to be processed by
    Qt, or false to continue with the standard event processing.

    Only one filter can be defined, but the filter can use the return
    value to call the previously set event filter. By default, no
    filter is set (i.e., the function returns 0).

    \sa installEventFilter()
*/
QCoreApplication::EventFilter
QCoreApplication::setEventFilter(QCoreApplication::EventFilter filter)
{
    Q_D(QCoreApplication);
    EventFilter old = d->eventFilter;
    d->eventFilter = filter;
    return old;
}

/*!
    Sends \a message through the event filter that was set by
    setEventFilter(). If no event filter has been set, this function
    returns false; otherwise, this function returns the result of the
    event filter function in the \a result parameter.

    \sa setEventFilter()
*/
bool QCoreApplication::filterEvent(void *message, long *result)
{
    Q_D(QCoreApplication);
    if (result)
        *result = 0;
    if (d->eventFilter)
        return d->eventFilter(message, result);
#ifdef Q_OS_WIN
    return winEventFilter(reinterpret_cast<MSG *>(message), result);
#else
    return false;
#endif
}

/*!
    This function returns true if there are pending events; otherwise
    returns false. Pending events can be either from the window
    system or posted events using postEvent().

    \sa QAbstractEventDispatcher::hasPendingEvents()
*/
bool QCoreApplication::hasPendingEvents()
{
    QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance();
    if (eventDispatcher)
        return eventDispatcher->hasPendingEvents();
    return false;
}

#ifdef QT3_SUPPORT
/*! \fn void QCoreApplication::lock()

    In Qt 3, this function locked the Qt library mutex, allowing
    non-GUI threads to perform basic printing operations using
    QPainter.

    In Qt 4, this is no longer supported, since painting is only
    supported from within a paint event handler. This function does
    nothing.

    \sa QWidget::paintEvent()
*/

/*! \fn void QCoreApplication::unlock(bool wakeUpGui)

    In Qt 3, this function unlocked the Qt library mutex. The mutex
    allowed non-GUI threads to perform basic printing operations
    using QPainter.

    In Qt 4, this is no longer supported, since painting is only
    supported from within a paint event handler. This function does
    nothing.
*/

/*! \fn bool QCoreApplication::locked()

    This function does nothing. It is there to keep old code working.
    It always returns false.

    See lock() for details.
*/

/*! \fn bool QCoreApplication::tryLock()

    This function does nothing. It is there to keep old code working.
    It always returns false.

    See lock() for details.
*/

/*! \fn void QCoreApplication::processOneEvent()
    \obsolete

    Waits for an event to occur, processes it, then returns.

    This function is useful for adapting Qt to situations where the
    event processing must be grafted onto existing program loops.

    Using this function in new applications may be an indication of design
    problems.

    \sa processEvents(), exec(), QTimer
*/

/*! \obsolete

    This function enters the main event loop (recursively). Do not call
    it unless you really know what you are doing.
*/
int QCoreApplication::enter_loop()
{
    QThread *currentThread = QThread::currentThread();
    if (currentThread != mainThread()) {
        qWarning("QApplication::enter_loop() failed: must be called from the main thread.");
        return -1;
    }
    QEventLoop eventLoop;
    int returnCode = eventLoop.exec();
    return returnCode;
}

/*! \obsolete

    This function exits from a recursive call to the main event loop.
    Do not call it unless you are an expert.
*/
void QCoreApplication::exit_loop()
{
    QThread *currentThread = QThread::currentThread();
    if (currentThread != mainThread()) {
        qWarning("QApplication::exit_loop() failed: must be called from the main thread.");
        return;
    }
    QThreadData *data = QThreadData::get(currentThread);
    if (!data->eventLoops.isEmpty())
        data->eventLoops.top()->exit();
}

/*! \obsolete

    Returns the current loop level.
*/
int QCoreApplication::loopLevel()
{
    QThread *thr = mainThread();
    if (!thr)
        return -1;
    QThreadData *data = QThreadData::get(thr);
    return data->eventLoops.size();
}
#endif

/*!
    \fn void QCoreApplication::watchUnixSignal(int signal, bool watch)
    \internal
*/

/*!
    \fn void QCoreApplication::unixSignal(int number)
    \internal

    This signal is emitted whenever a Unix signal is received by the
    application. The Unix signal received is specified by its \a number.
*/

/*!
    \fn void qAddPostRoutine(QtCleanUpFunction ptr)
    \relates QCoreApplication

    Adds a global routine that will be called from the QApplication
    destructor. This function is normally used to add cleanup routines
    for program-wide functionality.

    The function specified by \a ptr should take no arguments and should
    return nothing. For example:

    \code
        static int *global_ptr = 0;

        static void cleanup_ptr()
        {
            delete [] global_ptr;
            global_ptr = 0;
        }

        void init_ptr()
        {
            global_ptr = new int[100];      // allocate data
            qAddPostRoutine(cleanup_ptr);   // delete later
        }
    \endcode

    Note that for an application- or module-wide cleanup,
    qAddPostRoutine() is often not suitable. For example, if the
    program is split into dynamically loaded modules, the relevant
    module may be unloaded long before the QApplication destructor is
    called.

    For modules and libraries, using a reference-counted
    initialization manager or Qt's parent-child deletion mechanism may
    be better. Here is an example of a private class that uses the
    parent-child mechanism to call a cleanup function at the right
    time:

    \code
        class MyPrivateInitStuff : public QObject
        {
        public:
            static MyPrivateInitStuff *initStuff(QObject *parent)
            {
                if (!p)
                    p = new MyPrivateInitStuff(parent);
                return p;
            }

            ~MyPrivateInitStuff()
            {
                // cleanup goes here
            }

        private:
            MyPrivateInitStuff(QObject *parent)
                : QObject(parent)
            {
                // initialization goes here
            }

            MyPrivateInitStuff *p;
        };
    \endcode

    By selecting the right parent object, this can often be made to
    clean up the module's data at the right moment.
*/

/*!
    \macro Q_DECLARE_TR_FUNCTIONS(context)
    \relates QCoreApplication

    The Q_DECLARE_TR_FUNCTIONS() macro declares and implements two
    translation functions, \c tr() and \c trUtf8(), with these
    signatures:

    \code
        static inline QString tr(const char *sourceText,
                                 const char *comment = 0);
        static inline QString trUtf8(const char *sourceText,
                                     const char *comment = 0);
    \endcode

    This macro is useful if you want to use QObject::tr() or
    QObject::trUtf8() in classes that don't inherit from QObject.

    Q_DECLARE_TR_FUNCTIONS() must appear at the very top of the
    class definition (before the first \c{public:} or \c{protected:}).
    For example:

    \code
        class MyMfcView : public CView
        {
            Q_DECLARE_TR_FUNCTIONS(MyMfcView)

        public:
            MyMfcView();
            ...
        };
    \endcode

    The \e context parameter is normally the class name.

    \sa Q_OBJECT, QObject::tr(), QObject::trUtf8()
*/