qsize.cpp

奇趣公司比较新的qt/emd版本

    }
    return s;
}
#endif // QT_NO_DATASTREAM

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QSize &s) {
    dbg.nospace() << "QSize(" << s.width() << ',' << s.height() << ')';
    return dbg.space();
}
#endif



/*!
    \class QSizeF
    \brief The QSizeF class defines the size of a two-dimensional object
    using floating point precision.

    \ingroup multimedia

    A size is specified by a width() and a height().  It can be set in
    the constructor and changed using the setWidth(), setHeight(), or
    scale() functions, or using arithmetic operators. A size can also
    be manipulated directly by retrieving references to the width and
    height using the rwidth() and rheight() functions. Finally, the
    width and height can be swapped using the transpose() function.

    The isValid() function determines if a size is valid. A valid size
    has both width and height greater than or equal to zero. The
    isEmpty() function returns true if either of the width and height
    is \e less than (or equal to) zero, while the isNull() function
    returns true only if both the width and the height is zero.

    Use the expandedTo() function to retrieve a size which holds the
    maximum height and width of this size and a given
    size. Similarly, the boundedTo() function returns a size which
    holds the minimum height and width of this size and a given size.

    The QSizeF class also provides the toSize() function returning a
    QSize copy of this size, constructed by rounding the width and
    height to the nearest integers.

    QSizeF objects can be streamed as well as compared.

    \sa QSize, QPointF, QRectF
*/


/*****************************************************************************
  QSizeF member functions
 *****************************************************************************/

/*!
    \fn QSizeF::QSizeF()

    Constructs an invalid size.

    \sa isValid()
*/

/*!
    \fn QSizeF::QSizeF(const QSize &size)

    Constructs a size with floating point accuracy from the given \a
    size.

    \sa toSize()
*/

/*!
    \fn QSizeF::QSizeF(qreal width, qreal height)

    Constructs a size with the given \a width and \a height.
*/

/*!
    \fn bool QSizeF::isNull() const

    Returns true if both the width and height is 0; otherwise returns
    false.

    \sa isValid(), isEmpty()
*/

/*!
    \fn bool QSizeF::isEmpty() const

    Returns true if either of the width and height is less than or
    equal to 0; otherwise returns false.

    \sa isNull(), isValid()
*/

/*!
    \fn bool QSizeF::isValid() const

    Returns true if both the width and height is equal to or greater
    than 0; otherwise returns false.

    \sa isNull(), isEmpty()
*/

/*!
    \fn int QSizeF::width() const

    Returns the width.

    \sa height(), setWidth()
*/

/*!
    \fn int QSizeF::height() const

    Returns the height.

    \sa width(), setHeight()
*/

/*!
    \fn void QSizeF::setWidth(qreal width)

    Sets the width to the given \a width.

    \sa width(), rwidth(), setHeight()
*/

/*!
    \fn void QSizeF::setHeight(qreal height)

    Sets the height to the given \a height.

    \sa height(), rheight(), setWidth()
*/

/*!
    \fn QSize QSizeF::toSize() const

    Returns an integer based copy of this size.

    Note that the coordinates in the returned size will be rounded to
    the nearest integer.

    \sa QSizeF()
*/

/*!
    Swaps the width and height values.

    \sa setWidth(), setHeight()
*/

void QSizeF::transpose()
{
    qreal tmp = wd;
    wd = ht;
    ht = tmp;
}

/*!
  \fn void QSizeF::scale(qreal width, qreal height, Qt::AspectRatioMode mode)

    Scales the size to a rectangle with the given \a width and \a
    height, according to the specified \a mode.

    \list
    \i If \a mode is Qt::IgnoreAspectRatio, the size is set to (\a width, \a height).
    \i If \a mode is Qt::KeepAspectRatio, the current size is scaled to a rectangle
       as large as possible inside (\a width, \a height), preserving the aspect ratio.
    \i If \a mode is Qt::KeepAspectRatioByExpanding, the current size is scaled to a rectangle
       as small as possible outside (\a width, \a height), preserving the aspect ratio.
    \endlist

    Example:
    \code
        QSizeF t1(10, 12);
        t1.scale(60, 60, Qt::IgnoreAspectRatio);
        // t1 is (60, 60)

        QSizeF t2(10, 12);
        t2.scale(60, 60, Qt::KeepAspectRatio);
        // t2 is (50, 60)

        QSizeF t3(10, 12);
        t3.scale(60, 60, Qt::KeepAspectRatioByExpanding);
        // t3 is (60, 72)
    \endcode

    \sa setWidth(), setHeight()
*/

/*!
    \fn void QSizeF::scale(const QSizeF &size, Qt::AspectRatioMode mode)
    \overload

    Scales the size to a rectangle with the given \a size, according to
    the specified \a mode.
*/
void QSizeF::scale(const QSizeF &s, Qt::AspectRatioMode mode)
{
    if (mode == Qt::IgnoreAspectRatio) {
        wd = s.wd;
        ht = s.ht;
    } else {
        bool useHeight;
        qreal rw = s.ht * wd / ht;

        if (mode == Qt::KeepAspectRatio) {
            useHeight = (rw <= s.wd);
        } else { // mode == Qt::KeepAspectRatioByExpanding
            useHeight = (rw >= s.wd);
        }

        if (useHeight) {
            wd = rw;
            ht = s.ht;
        } else {
            ht = s.wd * ht / wd;
            wd = s.wd;
        }
    }
}

/*!
    \fn int &QSizeF::rwidth()

    Returns a reference to the width.

    Using a reference makes it possible to manipulate the width
    directly. For example:

    \code
        QSizeF size(100.3, 10);
        size.rwidth() += 20.5;

         // size becomes (120.8,10)
    \endcode

    \sa rheight(), setWidth()
*/

/*!
    \fn int &QSizeF::rheight()

    Returns a reference to the height.

    Using a reference makes it possible to manipulate the height
    directly. For example:

    \code
        QSizeF size(100, 10.2);
        size.rheight() += 5.5;

        // size becomes (100,15.7)
    \endcode

    \sa rwidth(), setHeight()
*/

/*!
    \fn QSizeF &QSizeF::operator+=(const QSizeF &size)

    Adds the given \a size to this size and returns a reference to
    this size. For example:

    \code
        QSizeF s( 3, 7);
        QSizeF r(-1, 4);
        s += r;

        // s becomes (2,11)
    \endcode
*/

/*!
    \fn QSizeF &QSizeF::operator-=(const QSizeF &size)

    Subtracts the given \a size from this size and returns a reference
    to this size. For example:

    \code
        QSizeF s( 3, 7);
        QSizeF r(-1, 4);
        s -= r;

        // s becomes (4,3)
    \endcode
*/

/*!
    \fn QSizeF &QSizeF::operator*=(qreal factor)
    \overload

    Multiplies both the width and height by the given \a factor and
    returns a reference to the size.

    \sa scale()
*/

/*!
    \fn bool operator==(const QSizeF &s1, const QSizeF &s2)
    \relates QSizeF

    Returns true if \a s1 and \a s2 are equal; otherwise returns
    false.
*/

/*!
    \fn bool operator!=(const QSizeF &s1, const QSizeF &s2)
    \relates QSizeF

    Returns true if \a s1 and \a s2 are different; otherwise returns false.
*/

/*!
    \fn const QSizeF operator+(const QSizeF &s1, const QSizeF &s2)
    \relates QSizeF

    Returns the sum of \a s1 and \a s2; each component is added separately.
*/

/*!
    \fn const QSizeF operator-(const QSizeF &s1, const QSizeF &s2)
    \relates QSizeF

    Returns \a s2 subtracted from \a s1; each component is subtracted
    separately.
*/

/*!
    \fn const QSizeF operator*(const QSizeF &size, qreal factor)

    \overload
    \relates QSizeF

    Multiplies the given \a size by the given \a factor and returns
    the result.

    \sa QSizeF::scale()
*/

/*!
    \fn const QSizeF operator*(qreal factor, const QSizeF &size)

    \overload
    \relates QSizeF

    Multiplies the given \a size by the given \a factor and returns
    the result.
*/

/*!
    \fn QSizeF &QSizeF::operator/=(qreal divisor)

    \overload

    Divides both the width and height by the given \a divisor and
    returns a reference to the size.

    \sa scale()
*/

/*!
    \fn const QSizeF operator/(const QSizeF &size, qreal divisor)

    \relates QSizeF
    \overload

    Divides the given \a size by the given \a divisor and returns the
    result.

    \sa QSizeF::scale()
*/

/*!
    \fn QSizeF QSizeF::expandedTo(const QSizeF & otherSize) const

    Returns a size holding the maximum width and height of this size
    and the given \a otherSize.

    \sa boundedTo(), scale()
*/

/*!
    \fn QSizeF QSizeF::boundedTo(const QSizeF & otherSize) const

    Returns a size holding the minimum width and height of this size
    and the given \a otherSize.

    \sa expandedTo(), scale()
*/



/*****************************************************************************
  QSizeF stream functions
 *****************************************************************************/
#ifndef QT_NO_DATASTREAM
/*!
    \fn QDataStream &operator<<(QDataStream &stream, const QSizeF &size)
    \relates QSizeF

    Writes the the given \a size to the given \a stream and returns a
    reference to the stream.

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator<<(QDataStream &s, const QSizeF &sz)
{
    s << double(sz.width()) << double(sz.height());
    return s;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QSizeF &size)
    \relates QSizeF

    Reads a size from the given \a stream into the given \a size and
    returns a reference to the stream.

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator>>(QDataStream &s, QSizeF &sz)
{
    double w, h;
    s >> w;
    s >> h;
    sz.setWidth(qreal(w));
    sz.setHeight(qreal(h));
    return s;
}
#endif // QT_NO_DATASTREAM

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QSizeF &s) {
    dbg.nospace() << "QSizeF(" << s.width() << ',' << s.height() << ')';
    return dbg.space();
}
#endif