qglobal.cpp

QT 开发环境里面一个很重要的文件

                qCritical("File '%s' does not exist!", qPrintable(fileName));
        }
    \endcode

    \warning The internal buffer is limited to 8192 bytes, including
    the '\0'-terminator.

    \warning Passing (const char *)0 as argument to qCritical might
    lead to crashes on certain platforms due to the platforms printf
    implementation.

    \sa qDebug(), qWarning(), qFatal(), qInstallMsgHandler(),
        {Debugging Techniques}
*/
void qCritical(const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg); // use variable arg list
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qt_message_output(QtCriticalMsg, buf);
}
#ifdef QT3_SUPPORT
void qSystemWarning(const char *msg, int code)
   { qCritical("%s (%s)", msg, qt_error_string(code).toLocal8Bit().constData()); }
#endif // QT3_SUPPORT

void qErrnoWarning(const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg);
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qCritical("%s (%s)", buf, qt_error_string(-1).toLocal8Bit().constData());
}

void qErrnoWarning(int code, const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg);
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qCritical("%s (%s)", buf, qt_error_string(code).toLocal8Bit().constData());
}

/*!
    \relates <QtGlobal>

    Calls the message handler with the fatal message \a msg. If no
    message handler has been installed, the message is printed to
    stderr. Under Windows, the message is sent to the debugger.

    For a release library this function will exit the application
    with return value 1. For the debug version this function will
    abort on Unix systems to create a core dump, and report a
    _CRT_ERROR on Windows allowing to connect a debugger to the
    application.

    This function takes a format string and a list of arguments,
    similar to the C printf() function.

    Example:
    \code
        int divide(int a, int b)
        {
            if (b == 0)                                // program error
                qFatal("divide: cannot divide by zero");
            return a / b;
        }
    \endcode

    \warning The internal buffer is limited to 8192 bytes, including
    the '\0'-terminator.

    \warning Passing (const char *)0 as argument to qFatal might lead
    to crashes on certain platforms due to the platforms printf implementation.

    \sa qDebug(), qCritical(), qWarning(), qInstallMsgHandler(),
        {Debugging Techniques}
*/
void qFatal(const char *msg, ...)
{
    char buf[QT_BUFFER_LENGTH];
    buf[QT_BUFFER_LENGTH - 1] = '\0';
    va_list ap;
    va_start(ap, msg); // use variable arg list
    qvsnprintf(buf, QT_BUFFER_LENGTH - 1, msg, ap);
    va_end(ap);

    qt_message_output(QtFatalMsg, buf);
}

// getenv is declared as deprecated in VS2005. This function
// makes use of the new secure getenv function.
QByteArray qgetenv(const char *varName)
{
#if defined(_MSC_VER) && _MSC_VER >= 1400
    size_t requiredSize;
    QByteArray buffer;
    getenv_s(&requiredSize, 0, 0, varName);
    if (requiredSize == 0)
        return buffer;
    buffer.resize(int(requiredSize));
    getenv_s(&requiredSize, buffer.data(), requiredSize, varName);
    return buffer;
#else
    return QByteArray(::getenv(varName));
#endif
}


#if defined(Q_OS_UNIX) && !defined(QT_NO_THREAD)
static QThreadStorage<uint *> randTLS; // Thread Local Storage for seed value
#endif

/*!
    \since 4.2

    Thread-safe version of the standard C++ \c srand() function.

    Sets the argument \a seed to be used to generate a new random number sequence of
    pseudo random integers to be returned by qrand().

    If no seed value is provided, qrand() is automatically seeded with a value of 1.

    The sequence of random numbers generated is deterministic per thread. For example,
    if two threads call qsrand(1) and subsequently calls qrand(), the threads will get
    the same random number sequence.

    \sa qrand()
*/
void qsrand(uint seed)
{
#if defined(Q_OS_UNIX) && !defined(QT_NO_THREAD)
    if (!randTLS.hasLocalData())
        randTLS.setLocalData(new uint);
    *randTLS.localData() = seed;
#else
    // On Windows srand() and rand() already use Thread-Local-Storage
    // to store the seed between calls
    srand(seed);
#endif
}

/*!
    \since 4.2

    Thread-safe version of the standard C++ \c rand() function.

    Returns a value between 0 and \c RAND_MAX (defined in \c <cstdlib> and
    \c <stdlib.h>), the next number in the current sequence of pseudo-random
    integers.

    Use \c qsrand() to initialize the pseudo-random number generator with
    a seed value.

    \sa qsrand()
*/
int qrand()
{
#if defined(Q_OS_UNIX) && !defined(QT_NO_THREAD)
    if (!randTLS.hasLocalData()) {
        randTLS.setLocalData(new uint);
        *randTLS.localData() = 1;
    }

    return rand_r(randTLS.localData());
#else
    // On Windows srand() and rand() already use Thread-Local-Storage
    // to store the seed between calls
    return rand();
#endif
}

/*!
    \macro forever
    \relates <QtGlobal>

    This macro is provided for convenience for writing infinite
    loops.

    Example:

    \code
        forever {
            ...
        }
    \endcode

    It is equivalent to \c{for (;;)}.

    If you're worried about namespace pollution, you can disable this
    macro by adding the following line to your \c .pro file:

    \code
        CONFIG += no_keywords
    \endcode

    \sa Q_FOREVER
*/

/*!
    \macro Q_FOREVER
    \relates <QtGlobal>

    Same as \l{forever}.

    This macro is available even when \c no_keywords is specified
    using the \c .pro file's \c CONFIG variable.

    \sa foreach()
*/

/*!
    \macro foreach(variable, container)
    \relates <QtGlobal>

    This macro is used to implement Qt's \c foreach loop. The \a
    variable parameter is a variable name or variable definition; the
    \a container parameter is a Qt container whose value type
    corresponds to the type of the variable. See \l{The foreach
    Keyword} for details.

    If you're worried about namespace pollution, you can disable this
    macro by adding the following line to your \c .pro file:

    \code
        CONFIG += no_keywords
    \endcode

    \sa Q_FOREACH()
*/

/*!
    \macro Q_FOREACH(variable, container)
    \relates <QtGlobal>

    Same as foreach(\a variable, \a container).

    This macro is available even when \c no_keywords is specified
    using the \c .pro file's \c CONFIG variable.

    \sa foreach()
*/

/*!
    \macro const char *QT_TR_NOOP(const char *sourceText)
    \relates <QtGlobal>

    Marks the string literal \a sourceText for dynamic translation in
    the current context (class), i.e the stored \a sourceText will not
    be altered. For example:

    \code
        QString FriendlyConversation::greeting(int type)
        {
	    static const char *greeting_strings[] = {
	        QT_TR_NOOP("Hello"),
	        QT_TR_NOOP("Goodbye")
	    };
	    return tr(greeting_strings[type]);
        }
    \endcode

    The macro expands to \a sourceText.

    \sa QT_TRANSLATE_NOOP(), {Internationalization with Qt}
*/

/*!
    \macro const char *QT_TRANSLATE_NOOP(const char *context, const char *sourceText)
    \relates <QtGlobal>

    Marks the string literal \a sourceText for dynamic translation in
    the given \a context, i.e the stored \a sourceText will not be
    altered. The \a context is typically a class. For example:

    \code
        static const char *greeting_strings[] = {
	    QT_TRANSLATE_NOOP("FriendlyConversation", "Hello"),
	    QT_TRANSLATE_NOOP("FriendlyConversation", "Goodbye")
        };

        QString FriendlyConversation::greeting(int type)
        {
	    return tr(greeting_strings[type]);
        }

        QString global_greeting(int type)
        {
	    return qApp->translate("FriendlyConversation",
				   greeting_strings[type]);
        }
    \endcode

    The macro expands to \a sourceText.

    \sa QT_TR_NOOP(), {Internationalization with Qt}
*/

/*!
    \macro QT_POINTER_SIZE
    \relates <QtGlobal>

    Expands to the size of a pointer in bytes (4 or 8). This is
    equivalent to \c sizeof(void *) but can be used in a preprocessor
    directive.
*/

/*!
    \macro TRUE
    \relates <QtGlobal>
    \obsolete

    Synonym for \c true.

    \sa FALSE
*/

/*!
    \macro FALSE
    \relates <QtGlobal>
    \obsolete

    Synonym for \c false.

    \sa TRUE
*/

/*!
    \macro QABS(n)
    \relates <QtGlobal>
    \obsolete

    Use qAbs(\a n) instead.

    \sa QMIN(), QMAX()
*/

/*!
    \macro QMIN(x, y)
    \relates <QtGlobal>
    \obsolete

    Use qMin(\a x, \a y) instead.

    \sa QMAX(), QABS()
*/

/*!
    \macro QMAX(x, y)
    \relates <QtGlobal>
    \obsolete

    Use qMax(\a x, \a y) instead.

    \sa QMIN(), QABS()
*/

/*!
    \macro const char *qPrintable(const QString &str)
    \relates <QtGlobal>

    Returns \a str as a \c{const char *}. This is equivalent to
    \a{str}.toLocal8bit().constData().

    Example:

    \code
        qWarning("%s: %s", qPrintable(key), qPrintable(value));
    \endcode

    \sa qDebug(), qWarning(), qCritical(), qFatal()
*/

/*!
    \macro Q_DECLARE_TYPEINFO(Type, Flags)
    \relates <QtGlobal>

    You can use this macro to specify information about a custom type
    \a Type. With accurate type information, Qt's \l{generic
    containers} can choose appropriate storage methods and algorithms.

    \a Flags can be one of the following:

    \list
    \o \c Q_PRIMITIVE_TYPE specifies that \a Type is a POD (plain old
       data) type with no constructor or destructor.
    \o \c Q_MOVABLE_TYPE specifies that \a Type has a constructor
       and/or a destructor but can be moved in memory using \c
       memcpy().
    \o \c Q_COMPLEX_TYPE (the default) specifies that \a Type has
       constructors and/or a destructor and that it may not be moved
       in memory.
    \endlist

    Example of a "primitive" type:

    \code
        struct Point2D
        {
            int x;
            int y;
        };

        Q_DECLARE_TYPEINFO(Point2D, Q_PRIMITIVE_TYPE);
    \endcode

    Example of a movable type:

    \code
        class Point2D
        {
        public:
            Point2D() { data = new int[2]; }
            Point2D(const Point2D &other) { ... }
            ~Point2D() { delete[] data; }

            Point2D &operator=(const Point2D &other) { ... }

            int x() const { return data[0]; }
            int y() const { return data[1]; }

        private:
            int *data;
        };

        Q_DECLARE_TYPEINFO(Point2D, Q_MOVABLE_TYPE);
    \endcode
*/

/*!
    \macro Q_UNUSED(name)
    \relates <QtGlobal>

    Indicates to the compiler that the parameter with the specified
    \a name is not used in the body of a function. This can be used to
    suppress compiler warnings while allowing functions to be defined
    with meaningful parameter names in their signatures.
*/

#if defined(QT3_SUPPORT) && !defined(QT_NO_SETTINGS)
#include <qlibraryinfo.h>
static const char *qInstallLocation(QLibraryInfo::LibraryLocation loc)
{
    static QByteArray ret;
    ret = QLibraryInfo::location(loc).toLatin1();
    return ret.constData();
}
const char *qInstallPath()
{
    return qInstallLocation(QLibraryInfo::PrefixPath);
}
const char *qInstallPathDocs()
{
    return qInstallLocation(QLibraryInfo::DocumentationPath);
}
const char *qInstallPathHeaders()
{
    return qInstallLocation(QLibraryInfo::HeadersPath);
}
const char *qInstallPathLibs()
{
    return qInstallLocation(QLibraryInfo::LibrariesPath);
}
const char *qInstallPathBins()
{
    return qInstallLocation(QLibraryInfo::BinariesPath);
}
const char *qInstallPathPlugins()
{
    return qInstallLocation(QLibraryInfo::PluginsPath);
}
const char *qInstallPathData()
{
    return qInstallLocation(QLibraryInfo::DataPath);
}
const char *qInstallPathTranslations()
{
    return qInstallLocation(QLibraryInfo::TranslationsPath);
}
const char *qInstallPathSysconf()
{
    return qInstallLocation(QLibraryInfo::SettingsPath);
}
#endif

struct QInternal_CallBackTable {
    QVector<QList<qInternalCallback> > callbacks;
};

Q_GLOBAL_STATIC(QInternal_CallBackTable, global_callback_table);

bool QInternal::registerCallback(Callback cb, qInternalCallback callback)
{
    if (cb >= 0 && cb < QInternal::LastCallback) {
        QInternal_CallBackTable *cbt = global_callback_table();
        cbt->callbacks.resize(cb + 1);
        cbt->callbacks[cb].append(callback);
        return true;
    }
    return false;
}

bool QInternal::unregisterCallback(Callback cb, qInternalCallback callback)
{
    if (cb >= 0 && cb < QInternal::LastCallback) {
        QInternal_CallBackTable *cbt = global_callback_table();
        return (bool) cbt->callbacks[cb].removeAll(callback);
    }
    return false;
}

bool QInternal::activateCallbacks(Callback cb, void **parameters)
{
    Q_ASSERT_X(cb >= 0, "QInternal::activateCallback()", "Callback id must be a valid id");

    QInternal_CallBackTable *cbt = global_callback_table();
    if (cbt && cb < cbt->callbacks.size()) {
        QList<qInternalCallback> callbacks = cbt->callbacks[cb];
        bool ret = false;
        for (int i=0; i<callbacks.size(); ++i)
            ret |= (callbacks.at(i))(p