qfont.cpp

奇趣公司比较新的qt/emd版本

*/

#ifndef QT_NO_DEBUG
static void qt_font_thread_test()
{
    if (QApplication::instance() && QThread::currentThread() != QApplication::instance()->thread())
        qWarning("QFont: It is not safe to use text and fonts outside the GUI thread");
}
#endif

/*!
  Constructs a font from \a font for use on the paint device \a pd.
*/
QFont::QFont(const QFont &font, QPaintDevice *pd)
    : resolve_mask(font.resolve_mask)
{
    Q_ASSERT(pd != 0);
    int dpi = pd->logicalDpiY();
#ifdef Q_WS_X11
    const QX11Info *info = qt_x11Info(pd);
    int screen = info ? info->screen() : 0;
#else
    const int screen = 0;
#endif
    if (font.d->dpi != dpi || font.d->screen != screen ) {
        d = new QFontPrivate(*font.d);
        d->dpi = dpi;
        d->screen = screen;
    } else {
        d = font.d;
        d->ref.ref();
    }
#ifdef Q_WS_WIN
    if (pd->devType() == QInternal::Printer && pd->getDC())
        d->hdc = pd->getDC();
#endif
}

/*!
  \internal
*/
QFont::QFont(QFontPrivate *data)
    : resolve_mask(QFontPrivate::Complete)
{
#ifndef QT_NO_DEBUG
    qt_font_thread_test();
#endif

    d = data;
    d->ref.ref();
}

/*! \internal
    Detaches the font object from common font data.
*/
void QFont::detach()
{
    if (d->ref == 1) {
        if (d->engineData)
            d->engineData->ref.deref();
        d->engineData = 0;
        return;
    }

    qAtomicDetach(d);
}

/*!
    Constructs a font object that uses the application's default font.

    \sa QApplication::setFont(), QApplication::font()
*/
QFont::QFont()
    :d(QApplication::font().d), resolve_mask(0)
{
    d->ref.ref();
}

/*!
    Constructs a font object with the specified \a family, \a
    pointSize, \a weight and \a italic settings.

    If \a pointSize is <= 0, it is set to 12.

    The \a family name may optionally also include a foundry name,
    e.g. "Helvetica [Cronyx]". If the \a family is
    available from more than one foundry and the foundry isn't
    specified, an arbitrary foundry is chosen. If the family isn't
    available a family will be set using the \l{QFont}{font matching}
    algorithm.

    \sa Weight, setFamily(), setPointSize(), setWeight(), setItalic(),
    setStyleHint() QApplication::font()
*/
QFont::QFont(const QString &family, int pointSize, int weight, bool italic)
    :d(new QFontPrivate)
{
#ifndef QT_NO_DEBUG
    qt_font_thread_test();
#endif

    resolve_mask = QFontPrivate::Family;

    if (pointSize <= 0) {
        pointSize = 12;
    } else {
        resolve_mask |= QFontPrivate::Size;
    }

    if (weight < 0) {
        weight = Normal;
    } else {
        resolve_mask |= QFontPrivate::Weight | QFontPrivate::Style;
    }

    d->request.family = family;
    d->request.pointSize = qreal(pointSize);
    d->request.pixelSize = -1;
    d->request.weight = weight;
    d->request.style = italic ? QFont::StyleItalic : QFont::StyleNormal;
}

/*!
    Constructs a font that is a copy of \a font.
*/
QFont::QFont(const QFont &font)
{
    d = font.d;
    d->ref.ref();
    resolve_mask = font.resolve_mask;
}

/*!
    Destroys the font object and frees all allocated resources.
*/
QFont::~QFont()
{
    if (!d->ref.deref())
        delete d;
}

/*!
    Assigns \a font to this font and returns a reference to it.
*/
QFont &QFont::operator=(const QFont &font)
{
    qAtomicAssign(d, font.d);
    resolve_mask = font.resolve_mask;
    return *this;
}

/*!
    Returns the requested font family name, i.e. the name set in the
    constructor or the last setFont() call.

    \sa setFamily() substitutes() substitute()
*/
QString QFont::family() const
{
    return d->request.family;
}

/*!
    Sets the family name of the font. The name is case insensitive and
    may include a foundry name.

    The \a family name may optionally also include a foundry name,
    e.g. "Helvetica [Cronyx]". If the \a family is
    available from more than one foundry and the foundry isn't
    specified, an arbitrary foundry is chosen. If the family isn't
    available a family will be set using the \l{QFont}{font matching}
    algorithm.

    \sa family(), setStyleHint(), QFontInfo
*/
void QFont::setFamily(const QString &family)
{
    detach();

    d->request.family = family;
#if defined(Q_WS_X11)
    d->request.addStyle.clear();
#endif // Q_WS_X11

    resolve_mask |= QFontPrivate::Family;
}

/*!
    Returns the point size of the font. Returns -1 if the font size
    was specified in pixels.

    \sa setPointSize() pointSizeF()
*/
int QFont::pointSize() const
{
    return qRound(d->request.pointSize);
}

/*!
    Sets the point size to \a pointSize. The point size must be
    greater than zero.

    \sa pointSize() setPointSizeF()
*/
void QFont::setPointSize(int pointSize)
{
    Q_ASSERT_X (pointSize > 0, "QFont::setPointSize", "point size must be greater than 0");

    detach();

    d->request.pointSize = qreal(pointSize);
    d->request.pixelSize = -1;

    resolve_mask |= QFontPrivate::Size;
}

/*!
    Sets the point size to \a pointSize. The point size must be
    greater than zero. The requested precision may not be achieved on
    all platforms.

    \sa pointSizeF() setPointSize() setPixelSize()
*/
void QFont::setPointSizeF(qreal pointSize)
{
    Q_ASSERT_X(pointSize > 0.0, "QFont::setPointSizeF", "point size must be greater than 0");

    detach();

    d->request.pointSize = pointSize;
    d->request.pixelSize = -1;

    resolve_mask |= QFontPrivate::Size;
}

/*!
    Returns the point size of the font. Returns -1 if the font size was
    specified in pixels.

    \sa pointSize() setPointSizeF() pixelSize() QFontInfo::pointSize() QFontInfo::pixelSize()
*/
qreal QFont::pointSizeF() const
{
    return d->request.pointSize;
}

/*!
    Sets the font size to \a pixelSize pixels.

    Using this function makes the font device dependent. Use
    setPointSize() or setPointSizeF() to set the size of the font
    in a device independent manner.

    \sa pixelSize()
*/
void QFont::setPixelSize(int pixelSize)
{
    if (pixelSize <= 0) {
        qWarning("QFont::setPixelSize: Pixel size <= 0 (%d)", pixelSize);
        return;
    }

    detach();

    d->request.pixelSize = pixelSize;
    d->request.pointSize = -1;

    resolve_mask |= QFontPrivate::Size;
}

/*!
    Returns the pixel size of the font if it was set with
    setPixelSize(). Returns -1 if the size was set with setPointSize()
    or setPointSizeF().

    \sa setPixelSize() pointSize() QFontInfo::pointSize() QFontInfo::pixelSize()
*/
int QFont::pixelSize() const
{
    return d->request.pixelSize;
}

#ifdef QT3_SUPPORT
/*! \obsolete

  Sets the logical pixel height of font characters when shown on
  the screen to \a pixelSize.
*/
void QFont::setPixelSizeFloat(qreal pixelSize)
{
    setPixelSize((int)pixelSize);
}
#endif

/*!
  \fn bool QFont::italic() const

    Returns true if the style() of the font is not QFont::StyleNormal

    \sa setItalic() style()
*/

/*!
  \fn void QFont::setItalic(bool enable)

  Sets the style() of the font to QFont::StyleItalic if \a enable is true;
  otherwise the style is set to QFont::StyleNormal.

  \sa italic() QFontInfo
*/

/*!
    Returns the style of the font.

    \sa setStyle()
*/
QFont::Style QFont::style() const
{
    return (QFont::Style)d->request.style;
}


/*!
  Sets the style of the font to \a style.

  \sa italic(), QFontInfo
*/
void QFont::setStyle(Style style)
{
    detach();

    d->request.style = style;
    resolve_mask |= QFontPrivate::Style;
}

/*!
    Returns the weight of the font which is one of the enumerated
    values from \l{QFont::Weight}.

    \sa setWeight(), Weight, QFontInfo
*/
int QFont::weight() const
{
    return d->request.weight;
}

/*!
    \enum QFont::Weight

    Qt uses a weighting scale from 0 to 99 similar to, but not the
    same as, the scales used in Windows or CSS. A weight of 0 is
    ultralight, whilst 99 will be an extremely black.

    This enum contains the predefined font weights:

    \value Light 25
    \value Normal 50
    \value DemiBold 63
    \value Bold 75
    \value Black 87
*/

/*!
    Sets the weight the font to \a weight, which should be a value
    from the \l QFont::Weight enumeration.

    \sa weight(), QFontInfo
*/
void QFont::setWeight(int weight)
{
    Q_ASSERT_X(weight >= 0 && weight <= 99, "QFont::setWeight", "Weight must be between 0 and 99");

    detach();

    d->request.weight = weight;
    resolve_mask |= QFontPrivate::Weight;
}

/*!
    \fn bool QFont::bold() const

    Returns true if weight() is a value greater than \link Weight
    QFont::Normal \endlink; otherwise returns false.

    \sa weight(), setBold(), QFontInfo::bold()
*/

/*!
    \fn void QFont::setBold(bool enable)

    If \a enable is true sets the font's weight to \link Weight
    QFont::Bold \endlink; otherwise sets the weight to \link Weight
    QFont::Normal\endlink.

    For finer boldness control use setWeight().

    \sa bold(), setWeight()
*/

/*!
    Returns true if underline has been set; otherwise returns false.

    \sa setUnderline()
*/
bool QFont::underline() const
{
    return d->underline;
}

/*!
    If \a enable is true, sets underline on; otherwise sets underline
    off.

    \sa underline(), QFontInfo
*/
void QFont::setUnderline(bool enable)
{
    detach();

    d->underline = enable;
    resolve_mask |= QFontPrivate::Underline;
}

/*!
    Returns true if overline has been set; otherwise returns false.

    \sa setOverline()
*/
bool QFont::overline() const
{
    return d->overline;
}

/*!
  If \a enable is true, sets overline on; otherwise sets overline off.

  \sa overline(), QFontInfo
*/
void QFont::setOverline(bool enable)
{
    detach();

    d->overline = enable;
    resolve_mask |= QFontPrivate::Overline;
}

/*!
    Returns true if strikeout has been set; otherwise returns false.

    \sa setStrikeOut()
*/
bool QFont::strikeOut() const
{
    return d->strikeOut;
}

/*!
    If \a enable is true, sets strikeout on; otherwise sets strikeout
    off.

    \sa strikeOut(), QFontInfo
*/
void QFont::setStrikeOut(bool enable)
{
    detach();

    d->strikeOut = enable;
    resolve_mask |= QFontPrivate::StrikeOut;
}

/*!
    Returns true if fixed pitch has been set; otherwise returns false.

    \sa setFixedPitch(), QFontInfo::fixedPitch()
*/
bool QFont::fixedPitch() const
{
    return d->request.fixedPitch;
}

/*!
    If \a enable is true, sets fixed pitch on; otherwise sets fixed