qrect.cpp

奇趣公司比较新的qt/emd版本

    if (isNull() || r.isNull())
        return false;
    QRect r1 = normalized();
    QRect r2 = r.normalized();
    return (qMax(r1.x1, r2.x1) <= qMin(r1.x2, r2.x2) &&
             qMax(r1.y1, r2.y1) <= qMin(r1.y2, r2.y2));
}


/*!
    \fn bool operator==(const QRect &r1, const QRect &r2)
    \relates QRect

    Returns true if the rectangles \a r1 and \a r2 are equal,
    otherwise returns false.
*/


/*!
    \fn bool operator!=(const QRect &r1, const QRect &r2)
    \relates QRect

    Returns true if the rectangles \a r1 and \a r2 are different, otherwise
    returns false.
*/


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

    Writes the given \a rectangle to the given \a stream, and returns
    a reference to the stream.

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator<<(QDataStream &s, const QRect &r)
{
    if (s.version() == 1)
        s << (qint16)r.left() << (qint16)r.top()
          << (qint16)r.right() << (qint16)r.bottom();
    else
        s << (qint32)r.left() << (qint32)r.top()
          << (qint32)r.right() << (qint32)r.bottom();
    return s;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QRect &rectangle)
    \relates QRect

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

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator>>(QDataStream &s, QRect &r)
{
    if (s.version() == 1) {
        qint16 x1, y1, x2, y2;
        s >> x1; s >> y1; s >> x2; s >> y2;
        r.setCoords(x1, y1, x2, y2);
    }
    else {
        qint32 x1, y1, x2, y2;
        s >> x1; s >> y1; s >> x2; s >> y2;
        r.setCoords(x1, y1, x2, y2);
    }
    return s;
}

#endif // QT_NO_DATASTREAM


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

/*!
    \class QRectF
    \ingroup multimedia

    \brief The QRectF class defines a rectangle in the plane using floating
    point precision.

    A rectangle is normally expressed as an upper-left corner and a
    size.  The size (width and height) of a QRectF is always equivalent
    to the mathematical rectangle that forms the basis for its
    rendering.

    A QRectF can be constructed with a set of left, top, width and
    height integers, or from a QPoint and a QSize.  The following code
    creates two identical rectangles.

    \code
        QRectF r1(100, 200, 11, 16);
        QRectF r2(QPoint(100, 200), QSize(11, 16));
    \endcode

    There is also a third constructor creating a QRectF from a QRect,
    and a corresponding toRect() function that returns a QRect object
    based on the values of this rectangle (note that the coordinates
    in the returned rectangle are rounded to the nearest integer).

    The QRectF class provides a collection of functions that return
    the various rectangle coordinates, and enable manipulation of
    these. QRectF also provide functions to move the rectangle
    relative to the various coordinates. In addition there is a
    moveTo() function that moves the rectangle, leaving its top left
    corner at the given coordinates. Alternatively, the translate()
    function moves the rectangle the given offset relative to the
    current position, and the translated() function returns a
    translated copy of this rectangle.

    The size() function returns the rectange's dimensions as a
    QSize. The dimensions can also be retrieved separately using the
    width() and height() functions. To manipulate the dimensions use
    the setSize(), setWidth() or setHeight() functions. Alternatively,
    the size can be changed by applying either of the functions
    setting the rectangle coordinates, for example, setBottom() or
    setRight().

    The contains() function tells whether a given point is inside the
    rectangle or not, and the intersects() function returns true if
    this rectangle intersects with a given rectangle (otherwise
    false). The QRectF class also provides the intersected() function
    which returns the intersection rectangle, and the united() function
    which returns the rectangle that encloses the given rectangle and
    this:

    \table
    \row
    \o \inlineimage qrect-intersect.png
    \o \inlineimage qrect-unite.png
    \row
    \o intersected()
    \o united()
    \endtable

    The isEmpty() function returns true if the rectangle's width or
    height is less than, or equal to, 0. Note that an empty rectangle
    is not valid: The isValid() function returns true if both width
    and height is larger than 0. A null rectangle (isNull() == true)
    on the other hand, has both width and height set to 0.

    Note that due to the way QRect and QRectF are defined, an
    empty QRectF is defined in essentially the same way as QRect.

    Finally, QRectF objects can be streamed as well as compared.

    \tableofcontents

    \section1 Rendering

    When using an \l {QPainter::Antialiasing}{anti-aliased} painter,
    the boundary line of a QRectF will be rendered symmetrically on both
    sides of the mathematical rectangle's boundary line. But when
    using an aliased painter (the default) other rules apply.

    Then, when rendering with a one pixel wide pen the QRectF's boundary
    line will be rendered to the right and below the mathematical
    rectangle's boundary line.

    When rendering with a two pixels wide pen the boundary line will
    be split in the middle by the mathematical rectangle. This will be
    the case whenever the pen is set to an even number of pixels,
    while rendering with a pen with an odd number of pixels, the spare
    pixel will be rendered to the right and below the mathematical
    rectangle as in the one pixel case.

    \table
    \row
        \o \inlineimage qrect-diagram-zero.png
        \o \inlineimage qrectf-diagram-one.png
    \row
        \o Logical representation
        \o One pixel wide pen
    \row
        \o \inlineimage qrectf-diagram-two.png
        \o \inlineimage qrectf-diagram-three.png
    \row
        \o Two pixel wide pen
        \o Three pixel wide pen
    \endtable

    \section1 Coordinates

    The QRectF class provides a collection of functions that return
    the various rectangle coordinates, and enable manipulation of
    these. QRectF also provide functions to move the rectangle
    relative to the various coordinates.

    For example: the bottom(), setBottom() and moveBottom() functions:
    bottom() returns the y-coordinate of the rectangle's bottom edge,
    setBottom() sets the bottom edge of the rectangle to the given y
    coordinate (it may change the height, but will never change the
    rectangle's top edge) and moveBottom() moves the entire rectangle
    vertically, leaving the rectangle's bottom edge at the given y
    coordinate and its size unchanged.

    \image qrectf-coordinates.png

    It is also possible to add offsets to this rectangle's coordinates
    using the adjust() function, as well as retrieve a new rectangle
    based on adjustments of the original one using the adjusted()
    function. If either of the width and height is negative, use the
    normalized() function to retrieve a rectangle where the corners
    are swapped.

    In addition, QRectF provides the getCoords() function which extracts
    the position of the rectangle's top-left and bottom-right corner,
    and the getRect() function which extracts the rectangle's top-left
    corner, width and height. Use the setCoords() and setRect()
    function to manipulate the rectangle's coordinates and dimensions
    in one go.

    \sa QRect, QRegion
*/

/*****************************************************************************
  QRectF member functions
 *****************************************************************************/

/*!
    \fn QRectF::QRectF()

    Constructs a null rectangle.

    \sa isNull()
*/

/*!
    \fn QRectF::QRectF(const QPointF &topLeft, const QSizeF &size)

    Constructs a rectangle with the given \a topLeft corner and the given \a size.

    \sa setTopLeft(), setSize()
*/

/*!
    \fn QRectF::QRectF(const QPointF &topLeft, const QPointF &bottomRight)
    \since 4.3

    Constructs a rectangle with the given \a topLeft and \a bottomRight corners.

    \sa setTopLeft(), setBottomRight()
*/

/*!
    \fn QRectF::QRectF(qreal x, qreal y, qreal width, qreal height)

    Constructs a rectangle with (\a x, \a y) as its top-left corner
    and the given \a width and \a height.

    \sa setRect()
*/

/*!
    \fn QRectF::QRectF(const QRect &rectangle)

    Constructs a QRectF rectangle from the given QRect \a rectangle.

    \sa toRect()
*/

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

    Returns true if the rectangle is a null rectangle, otherwise returns false.

    A null rectangle has both the width and the height set to 0. A
    null rectangle is also empty, and hence not valid.

    \sa isEmpty(), isValid()
*/

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

    Returns true if the rectangle is empty, otherwise returns false.

    An empty rectangle has width() <= 0 or height() <= 0.  An empty
    rectangle is not valid (i.e., isEmpty() == !isValid()).

    Use the normalized() function to retrieve a rectangle where the
    corners are swapped.

    \sa isNull(),  isValid(),  normalized()
*/

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

    Returns true if the rectangle is valid, otherwise returns false.

    A valid rectangle has a width() > 0 and height() > 0. Note that
    non-trivial operations like intersections are not defined for
    invalid rectangles. A valid rectangle is not empty (i.e., isValid()
    == !isEmpty()).

    \sa isNull(), isEmpty(), normalized()
*/


/*!
    Returns a normalized rectangle; i.e., a rectangle that has a
    non-negative width and height.

    If width() < 0 the function swaps the left and right corners, and
    it swaps the top and bottom corners if height() < 0.

    \sa isValid(), isEmpty()
*/

QRectF QRectF::normalized() const
{
    QRectF r = *this;
    if (r.w < 0) {
        r.xp = r.xp + r.w;
        r.w = -r.w;
    }
    if (r.h < 0) {
        r.yp = r.yp + r.h;
        r.h = -r.h;
    }
    return r;
}

/*!
    \fn qreal QRectF::x() const

    Returns the x-coordinate of the rectangle's left edge. Equivalent
    to left().


    \sa setX(), y(), topLeft()
*/

/*!
    \fn qreal QRectF::y() const

    Returns the y-coordinate of the rectangle's top edge. Equivalent
    to top().

    \sa setY(), x(),  topLeft()
*/


/*!
    \fn void QRectF::setLeft(qreal x)

    Sets the left edge of the rectangle to the given \a x
    coordinate. May change the width, but will never change the right
    edge of the rectangle.

    Equivalent to setX().

    \sa left(), moveLeft()
*/

/*!
    \fn void QRectF::setTop(qreal y)

    Sets the top edge of the rectangle to the given \a y coordinate. May
    change the height, but will never change the bottom edge of the
    rectangle.

    Equivalent to setY().

    \sa top(), moveTop()
*/

/*!
    \fn void QRectF::setRight(qreal x)

    Sets the right edge of the rectangle to the given \a x
    coordinate. May change the width, but will never change the left
    edge of the rectangle.

    \sa right(), moveRight()
*/

/*!
    \fn void QRectF::setBottom(qreal y)

    Sets the bottom edge of the rectangle to the given \a y
    coordinate. May change the height, but will never change the top
    edge of the rectangle.

    \sa bottom(), moveBottom()
*/

/*!
    \fn void QRectF::setX(qreal x)

    Sets the left edge of the rectangle to the given \a x
    coordinate. May change the width, but will never change the right
    edge of the rectangle.

    Equivalent to setLeft().

    \sa x(), setY(), setTopLeft()
*/

/*!
    \fn void QRectF::setY(qreal y)

    Sets the top edge of the rectangle to the given \a y
    coordinate. May change the height, but will never change the
    bottom edge of the rectangle.

    Equivalent to setTop().

    \sa y(), setX(), setTopLeft()
*/

/*!
    \fn void QRectF::setTopLeft(const QPointF &position)

    Set the top-left corner of the rectangle to the given \a
    position. May change the size, but will the never change the
    bottom-right corner of the rectangle.

    \sa topLeft(), moveTopLeft()
*/

/*!
    \fn void QRectF::setBottomRight(const QPointF &position)

    Set the top-right corner of the rectangle to the given \a
    position. May change the size, but will the never change the
    top-left corner of the rectangle.

    \sa bottomRight(), moveBottomRight()
*/

/*!
    \fn void QRectF::setTopRight(const QPointF &position)

    Set the top-right corner of the rectangle to the given \a
    position. May change the size, but will the never change the
    bottom-left corner of the rectangle.

    \sa topRight(), moveTopRight()
*/

/*!
    \fn void QRectF::setBottomLeft(const QPointF &position)

    Set the bottom-left corner of the rectangle to the given \a
    position. May change the size, but will the never change the
    top-right corner of the rectangle.

    \sa bottomLeft(), moveBottomLeft()
*/

/*!
    \fn QPointF QRectF::center() const

    Returns the center point of the rectangle.

    \sa moveCenter()
*/


/*!
    \fn void QRectF::getRect(qreal *x, qreal *y, qreal *width, qreal *height) const

    Extracts the position of the rectangle's top-left corner to *\a x and
    *\a y, and its dimensions to *\a width and *\a height.

    \sa setRect(), getCoords()
*/


/*!
    \fn void QRectF::getCoords(qreal *x1, qreal *y1, qreal *x2, qreal *y2) const

    Extracts the position of the rectangle's top-left corner to *\a x1
    and *\a y1, and the position of the bottom-right corner to *\a x2 and
    *\a y2.

    \sa setCoords(), getRect()
*/

/*!
    \fn void QRectF::moveLeft(qreal x)

    Moves the rectangle horizontally, leaving the rectangle's left
    edge at the given \a x coordinate. The rectangle's size is
    unchanged.

    \sa left(), setLeft(), moveRight()
*/

/*!
    \fn void QRectF::moveTop(qreal y)

    Moves the rectangle vertically, leaving the rectangle's top line
    at the given \a y coordinate. The rectangle's size is unchanged.

    \sa top(), setTop(), moveBottom()
*/


/*!
    \fn void QRectF::moveRight(qreal x)

    Moves the rectangle horizontally, leaving the rectangle's right
    edge at the given \a x coordinate. The rectangle's size is
    unchanged.

    \sa right(), setRight(), moveLeft()
*/


/*!
    \fn void QRectF::moveBottom(qreal y)

    Moves the rectangle vertically, leaving the rectangle's bottom
    edge at the given \a y coordinate. The rectangle's size is
    unchanged.

    \sa bottom(), setBottom(), moveTop()
*/


/*!
    \fn void QRectF::moveTopLeft(const QPointF &position)