qbrush.cpp

奇趣公司比较新的qt/emd版本

        QGradient::Spread spread = QGradient::PadSpread;

        s >> type_as_int;
        type = QGradient::Type(type_as_int);
        if (s.version() >= QDataStream::Qt_4_3) {
            s >> type_as_int;
            spread = QGradient::Spread(type_as_int);
            s >> type_as_int;
            cmode = QGradient::CoordinateMode(type_as_int);
        }

        if (sizeof(qreal) == sizeof(double)) {
            s >> stops;
        } else {
            quint32 numStops;
            double n;
            QColor c;

            s >> numStops;
            for (quint32 i = 0; i < numStops; ++i) {
                s >> n >> c;
                stops << QPair<qreal, QColor>(n, c);
            }
        }

        if (type == QGradient::LinearGradient) {
            QPointF p1, p2;
            s >> p1;
            s >> p2;
            QLinearGradient lg(p1, p2);
            lg.setStops(stops);
            lg.setSpread(spread);
            lg.setCoordinateMode(cmode);
            b = QBrush(lg);
        } else if (type == QGradient::RadialGradient) {
            QPointF center, focal;
            double radius;
            s >> center;
            s >> focal;
            s >> radius;
            QRadialGradient rg(center, radius, focal);
            rg.setStops(stops);
            rg.setSpread(spread);
            rg.setCoordinateMode(cmode);
            b = QBrush(rg);
        } else { // type == QGradient::ConicalGradient
            QPointF center;
            double angle;
            s >> center;
            s >> angle;
            QConicalGradient cg(center, angle);
            cg.setStops(stops);
            cg.setSpread(spread);
            cg.setCoordinateMode(cmode);
            b = QBrush(cg);
        }
    } else {
        b = QBrush(color, (Qt::BrushStyle)style);
    }
    if (s.version() >= QDataStream::Qt_4_3) {
        QTransform transform;
        s >> transform;
        b.setTransform(transform);
    }
    return s;
}
#endif // QT_NO_DATASTREAM

/*******************************************************************************
 * QGradient implementations
 */


/*!
    \class QGradient
    \ingroup multimedia
    \ingroup shared

    \brief The QGradient class is used in combination with QBrush to
    specify gradient fills.

    Qt currently supports three types of gradient fills:

    \list
    \o \e Linear gradients interpolate colors between start and end points.
    \o \e Radial gradients interpolate colors between a focal point and end
        points on a circle surrounding it.
    \o \e Conical gradients interpolate colors around a center point.
    \endlist

    A gradient's type can be retrieved using the type() function.
    Each of the types is represented by a subclass of QGradient:

    \table
    \row
    \o \inlineimage qgradient-linear.png
    \o \inlineimage qgradient-radial.png
    \o \inlineimage qgradient-conical.png
    \header
    \o QLinearGradient
    \o QRadialGradient
    \o QConicalGradient
    \endtable

    The colors in a gradient is defined using stop points of the
    QGradientStop type, i.e. a position and a color.  Use the
    setColorAt() function to define a single stop
    point. Alternatively, use the setStops() function to define
    several stop points in one go. Note that the latter function \e
    replaces the current set of stop points.

    It is the gradient's complete set of stop points (accessible
    through the stops() function) that describes how the gradient area
    should be filled. If no stop points have been specified, a
    gradient of black at 0 to white at 1 is used.

    A diagonal linear gradient from black at (100, 100) to white at
    (200, 200) could be specified like this:

    \quotefromfile snippets/brush/brush.cpp
    \skipto LINEAR
    \skipto QLinearGradient
    \printuntil Qt::white

    A gradient can have an arbitrary number of stop points. The
    following would create a radial gradient starting with
    red in the center, blue and then green on the edges:

    \quotefromfile snippets/brush/brush.cpp
    \skipto RADIAL
    \skipto QRadialGradient
    \printuntil Qt::green

    It is possible to repeat or reflect the gradient outside its area
    by specifiying the \l {QGradient::Spread}{spread method} using the
    setSpread() function. The default is to pad the outside area with
    the color at the closest stop point. The currently set \l
    {QGradient::Spread}{spread method} can be retrieved using the
    spread() function. The QGradient::Spread enum defines three
    different methods:

    \table
    \row
    \o \inlineimage qradialgradient-pad.png
    \o \inlineimage qradialgradient-repeat.png
    \o \inlineimage qradialgradient-reflect.png
    \row
    \o \l {QGradient::PadSpread}{PadSpread}
    \o \l {QGradient::RepeatSpread}{RepeatSpread}
    \o \l {QGradient::ReflectSpread}{ReflectSpread}
    \endtable

    Note that the setSpread() function only has effect for linear and
    radial gradients. The reason is that the conical gradient is
    closed by definition, i.e. the \e conical gradient fills the
    entire circle from 0 - 360 degrees, while the boundary of a radial
    or a linear gradient can be specified through its radius or final
    stop points, respectively.

    \sa {demos/gradients}{The Gradients Demo}, QBrush
*/

/*!
    \internal
*/
QGradient::QGradient()
    : m_type(NoGradient), dummy(0)
{
}


/*!
    \enum QGradient::Type

    Specifies the type of gradient.

    \value LinearGradient  Interpolates colors between start and end points
    (QLinearGradient).

    \value RadialGradient Interpolate colors between a focal point and end
    points on a circle surrounding it (QRadialGradient).

    \value ConicalGradient Interpolate colors around a center point (QConicalGradient).
    \value NoGradient No gradient is used.

    \sa type()
*/

/*!
    \enum QGradient::Spread

    Specifies how the area outside the gradient area should be
    filled.

    \value PadSpread The area is filled with the closest stop
    color. This is the default.

    \value RepeatSpread The gradient  is repeated outside the gradient
    area.

    \value ReflectSpread The gradient is reflected outside the
    gradient area.

    \sa spread(), setSpread()
*/

/*!
    \fn void QGradient::setSpread(Spread method)

    Specifies the spread \a method that should be used for this
    gradient.

    Note that this function only has effect for linear and radial
    gradients.

    \sa spread()
*/

/*!
    \fn QGradient::Spread QGradient::spread() const

    Returns the spread method use by this gradient. The default is
    PadSpread.

    \sa setSpread()
*/

/*!
    \fn QGradient::Type QGradient::type() const

    Returns the type of gradient.
*/

/*!
    \fn void QGradient::setColorAt(qreal position, const QColor &color)

    Creates a stop point at the given \a position with the given \a
    color. The given \a position must be in the range 0 to 1.

    \sa setStops(), stops()
*/

void QGradient::setColorAt(qreal pos, const QColor &color)
{
    if (pos > 1 || pos < 0) {
        qWarning("QGradient::setColorAt: Color position must be specified in the range 0 to 1");
        return;
    }

    int index = 0;
    while (index < m_stops.size() && m_stops.at(index).first <= pos) ++index;
    m_stops.insert(index, QGradientStop(pos, color));
}

/*!
    \fn void QGradient::setStops(const QGradientStops &stopPoints)

    Replaces the current set of stop points with the given \a
    stopPoints. The positions of the points must be in the range 0 to
    1, and must be sorted with the lowest point first.

    \sa setColorAt(), stops()
*/
void QGradient::setStops(const QGradientStops &stops)
{
    m_stops.clear();
    for (int i=0; i<stops.size(); ++i)
        setColorAt(stops.at(i).first, stops.at(i).second);
}


/*!
    Returns the stop points for this gradient.

    If no stop points have been specified, a gradient of black at 0 to white
    at 1 is used.

    \sa setStops(), setColorAt()
*/
QGradientStops QGradient::stops() const
{
    if (m_stops.isEmpty()) {
        QGradientStops tmp;
        tmp << QGradientStop(0, Qt::black) << QGradientStop(1, Qt::white);
        return tmp;
    }
    return m_stops;
}

/*!
    \enum QGradient::CoordinateMode
    \internal

    This enum specifies how gradient coordinates map to the paint
    device on which the gradient is used.

    \value LogicalMode
    \value StretchToDeviceMode
    \value ObjectBoundingMode
*/

/*!
    \internal

    Returns the coordinate mode of this gradient. The default mode is
    LogicalMode.
*/
QGradient::CoordinateMode QGradient::coordinateMode() const
{
    if (dummy == 0)
        return LogicalMode;
    else if (dummy == (void*)1)
        return StretchToDeviceMode;
    else
        return ObjectBoundingMode;
}

/*!
    \internal

    Sets the coordinate mode of this gradient to \a mode. The default
    mode is LogicalMode.
*/
void QGradient::setCoordinateMode(CoordinateMode mode)
{
    if (mode == LogicalMode)
        dummy = 0;
    else if (mode == StretchToDeviceMode)
        dummy = (void *) 1;
    else
        dummy = (void *) 2;
}


/*!
    \fn bool QGradient::operator!=(const QGradient &gradient) const
    \since 4.2

    Returns true if the gradient is the same as the other \a gradient
    specified; otherwise returns false.

    \sa operator==()
*/

/*!
    Returns true if the gradient is the same as the other \a gradient
    specified; otherwise returns false.

    \sa operator!=()
*/
bool QGradient::operator==(const QGradient &gradient) const
{
    if (gradient.m_type != m_type
        || gradient.m_spread != m_spread
        || gradient.dummy != dummy) return false;

    if (m_type == LinearGradient) {
        if (m_data.linear.x1 != gradient.m_data.linear.x1
            || m_data.linear.y1 != gradient.m_data.linear.y1
            || m_data.linear.x2 != gradient.m_data.linear.x2
            || m_data.linear.y2 != gradient.m_data.linear.y2)
            return false;
    } else if (m_type == RadialGradient) {
        if (m_data.radial.cx != gradient.m_data.radial.cx
            || m_data.radial.cy != gradient.m_data.radial.cy
            || m_data.radial.fx != gradient.m_data.radial.fx
            || m_data.radial.fy != gradient.m_data.radial.fy
            || m_data.radial.radius != gradient.m_data.radial.radius)
            return false;
    } else { // m_type == ConicalGradient
        if (m_data.conical.cx != gradient.m_data.conical.cx
            || m_data.conical.cy != gradient.m_data.conical.cy
            || m_data.conical.angle != gradient.m_data.conical.angle)
            return false;
    }

    return stops() == gradient.stops();
}

/*!
    \internal
*/
bool QGradient::operator==(const QGradient &gradient)
{
    return const_cast<const QGradient *>(this)->operator==(gradient);
}

/*!
    \class QLinearGradient
    \ingroup multimedia

    \brief The QLinearGradient class is used in combination with QBrush to
    specify a linear gradient brush.

    Linear gradients interpolate colors between start and end
    points. Outside these points the gradient is either padded,
    reflected or repeated depending on the currently set \l
    {QGradient::Spread}{spread} method:

    \table
    \row
    \o \inlineimage qlineargradient-pad.png
    \o \inlineimage qlineargradient-reflect.png
    \o \inlineimage qlineargradient-repeat.png
    \row
    \o \l {QGradient::PadSpread}{PadSpread} (default)
    \o \l {QGradient::ReflectSpread}{ReflectSpread}
    \o \l {QGradient::RepeatSpread}{RepeatSpread}
    \endtable

    The colors in a gradient is defined using stop points of the
    QGradientStop type, i.e. a position and a color. Use the
    QGradient::setColorAt() or the QGradient::setStops() function to
    define the stop points. It is the gradient's complete set of stop
    points that describes how the gradient area should be filled. If
    no stop points have been specified, a gradient of black at 0 to
    white at 1 is used.

    In addition to the functions inherited from QGradient, the
    QLinearGradient class provides the finalStop() function which
    returns the final stop point of the gradient, and the start()
    function returning the start point of the gradient.

    \sa QRadialGradient, QConicalGradient, {demos/gradients}{The
    Gradients Demo}
*/


/*!
    Constructs a default linear gradient with interpolation area
    between (0, 0) and (1, 1).

    \sa QGradient::setColorAt(), setStart(), setFinalStop()
*/

QLinearGradient::QLinearGradient()
{
    m_type = LinearGradient;
    m_spread = PadSpread;
    m_data.linear.x1 = 0;
    m_data.linear.y1 = 0;
    m_data.linear.x2 = 1;
    m_data.linear.y2 = 1;
}


/*!
    Constructs a linear gradient with interpolation area between the
    given \a start point and \a finalStop.

    \sa QGradient::setColorAt(), QGradient::setStops()
*/
QLinearGradient::QLinearGradient(const QPointF &start, const QPointF &finalStop)
{
    m_type = LinearGradient;
    m_spread = PadSpread;
    m_data.linear.x1 = start.x();
    m_data.linear.y1 = start.y();
    m_data.linear.x2 = finalStop.x();
    m_data.linear.y2 = finalStop.y();
}

/*!
    \fn QLinearGradient::QLinearGradient(qreal x1, qreal y1, qreal x2, qreal y2)

    Constructs a linear gradient with interpolation area between (\a
    x1, \a y1) and (\a x2, \a y2).

    \sa QGradient::setColorAt(), QGradient::setStops()
*/
QLinearGradient::QLinearGradient(qreal xStart, qreal yStart, qreal xFinalStop, qreal yFinalStop)
{
    m_type = LinearGradient;
    m_spread = PadSpread;
    m_data.linear.x1 = xStart;
    m_data.linear.y1 = yStart;
    m_data.linear.x2 = xFinalStop;
    m_data.linear.y2 = yFinalStop;
}


/*!
    Returns the start point of this linear gradient in logical coordinates.

    \sa QGradient::stops()
*/

QPointF QLinearGradient::start() const
{
    Q_ASSERT(m_type == LinearGradient);
    return QPointF(m_data.linear.x1, m_data.linear.y1);
}

/*!
    \fn void QLinearGradient::setStart(qreal x, qreal y)
    \overload
    \since 4.2

    Sets the start point of this linear gradient in logical
    coordinates to \a x, \a y.

    \sa start()
*/

/*!
    \since 4.2

    Sets the start point of this linear gradient in logical
    coordinates to \a start.