/******************************************************************************** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.**** This file is part of the QtCore module of the Qt Toolkit.**** This file may be used under the terms of the GNU General Public** License version 2.0 as published by the Free Software Foundation** and appearing in the file LICENSE.GPL included in the packaging of** this file.  Please review the following information to ensure GNU** General Public Licensing requirements will be met:** http://www.trolltech.com/products/qt/opensource.html**** If you are unsure which license is appropriate for your use, please** review the following information:** http://www.trolltech.com/products/qt/licensing.html or contact the** sales department at sales@trolltech.com.**** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.******************************************************************************/#include "qrect.h"#include "qdatastream.h"#include "qdebug.h"/*!    \class QRect    \ingroup multimedia    \brief The QRect class defines a rectangle in the plane using    integer precision.    A rectangle is normally expressed as an upper-left corner and a    size.  The size (width and height) of a QRect is always equivalent    to the mathematical rectangle that forms the basis for its    rendering.    A QRect 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        QRect r1(100, 200, 11, 16);        QRect r2(QPoint(100, 200), QSize(11, 16));    \endcode    There is a third constructor that creates a QRect using the    top-left and bottom-right coordinates, but we recommend that you    avoid using it. The rationale is that for historical reasons the    values returned by the bottom() and right() functions deviate from    the true bottom-right corner of the rectangle.    The QRect class provides a collection of functions that return the    various rectangle coordinates, and enable manipulation of    these. QRect 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. The QRect 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 left() > right() or top() >    bottom(). Note that an empty rectangle is not valid: The isValid()    function returns true if left() <= right() \e and top() <=    bottom(). A null rectangle (isNull() == true) on the other hand,    has both width and height set to 0.    Finally, QRect 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 QRect 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 QRect'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 qrect-diagram-one.png    \row        \o Logical representation        \o One pixel wide pen    \row        \o \inlineimage qrect-diagram-two.png        \o \inlineimage qrect-diagram-three.png    \row        \o Two pixel wide pen        \o Three pixel wide pen    \endtable    \section1 Coordinates    The QRect class provides a collection of functions that return the    various rectangle coordinates, and enable manipulation of    these. QRect also provide functions to move the rectangle relative    to the various coordinates.    For example the left(), setLeft() and moveLeft() functions as an    example: left() returns the x-coordinate of the rectangle's left    edge, setLeft() sets the left edge of the rectangle to the given x    coordinate (it may change the width, but will never change the    rectangle's right edge) and moveLeft() moves the entire rectangle    horizontally, leaving the rectangle's left edge at the given x    coordinate and its size unchanged.    \image qrect-coordinates.png    Note that for historical reasons the values returned by the    bottom() and right() functions deviate from the true bottom-right    corner of the rectangle: The right() function returns \e { left()    + width() - 1} and the bottom() function returns \e {top() +    height() - 1}. The same is the case for the point returned by the    bottomRight() convenience function. In addition, the x and y    coordinate of the topRight() and bottomLeft() functions,    respectively, contain the same deviation from the true right and    bottom edges.    We recommend that you use x() + width() and y() + height() to find    the true bottom-right corner, and avoid right() and    bottom(). Another solution is to use QRectF: The QRectF class    defines a rectangle in the plane using floating point accuracy for    coordinates, and the QRectF::right() and QRectF::bottom()    functions \e do return the true bottom-right corner.    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, QRect 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 QRectF, QRegion*//*****************************************************************************  QRect member functions *****************************************************************************//*!    \fn QRect::QRect()    Constructs a null rectangle.    \sa isNull()*//*!    \fn QRect::QRect(const QPoint &topLeft, const QPoint &bottomRight)    Constructs a rectangle with the given \a topLeft and \a bottomRight corners.    \sa setTopLeft(), setBottomRight()*//*!    \fn QRect::QRect(const QPoint &topLeft, const QSize &size)    Constructs a rectangle with the given \a topLeft corner and the    given \a size.    \sa setTopLeft(), setSize()*//*!    \fn QRect::QRect(int x, int y, int width, int 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 bool QRect::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 (i.e.    right() == left() - 1 and bottom() == top() - 1). A null rectangle    is also empty, and hence is not valid.    \sa isEmpty(), isValid()*//*!    \fn bool QRect::isEmpty() const    Returns true if the rectangle is empty, otherwise returns false.    An empty rectangle has a left() > right() or top() > bottom(). 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 QRect::isValid() const    Returns true if the rectangle is valid, otherwise returns false.    A valid rectangle has a left() < right() and top() <    bottom(). 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()*/QRect QRect::normalized() const{    if (isNull() || width() == 0 || height() == 0)        return *this;    QRect r;    if (x2 < x1) {                                // swap bad x values        r.x1 = x2;        r.x2 = x1;    } else {        r.x1 = x1;        r.x2 = x2;    }    if (y2 < y1) {                                // swap bad y values        r.y1 = y2;        r.y2 = y1;    } else {        r.y1 = y1;        r.y2 = y2;    }    return r;}/*!    \fn QRect QRect::normalize() const    \compat    Returns a normalized rectangle, i.e. a rectangle that has a    non-negative width and height.    Use the normalized() function instead*//*!    \fn int QRect::left() const    Returns the x-coordinate of the rectangle's left edge. Equivalent    to x().    \sa setLeft(),  topLeft(), bottomLeft()*//*!    \fn int QRect::top() const    Returns the y-coordinate of the rectangle's top edge.    Equivalent to y().    \sa setTop(), topLeft(), topRight()*//*!    \fn int QRect::right() const    Returns the x-coordinate of the rectangle's right edge.    Note that for historical reasons this function returns left() +    width() - 1; use x() + width() to retrieve the true x-coordinate.    \sa setRight(), topRight(), bottomRight()*//*!    \fn int QRect::bottom() const    Returns the y-coordinate of the rectangle's bottom edge.    Note that for historical reasons this function returns top() +    height() - 1; use y() + height() to retrieve the true y-coordinate.    \sa setBottom(), bottomLeft(), bottomRight()*//*!    \fn int &QRect::rLeft()    \compat    Returns a reference to the left coordinate of the rectangle.    Use the left() function instead.*//*!    \fn int &QRect::rTop()    \compat    Returns a reference to the top coordinate of the rectangle.    Use the top() function instead.*//*!    \fn int &QRect::rRight()    \compat    Returns a reference to the right coordinate of the rectangle.    Use the right() function instead.*//*!    \fn int &QRect::rBottom()    \compat    Returns a reference to the bottom coordinate of the rectangle.    Use the bottom() function instead.*//*!    \fn int QRect::x() const    Returns the x-coordinate of the rectangle's left edge. Equivalent to left().    \sa setX(), y(), topLeft()*//*!    \fn int QRect::y() const    Returns the y-coordinate of the rectangle's top edge. Equivalent to top().    \sa setY(), x(), topLeft()*//*!    \fn void QRect::setLeft(int 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 QRect::setTop(int 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 QRect::setRight(int 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 QRect::setBottom(int 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 QRect::setX(int 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 QRect::setY(int 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 QRect::setTopLeft(const QPoint &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 QRect::setBottomRight(const QPoint &position)    Set the bottom-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 QRect::setTopRight(const QPoint &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 QRect::setBottomLeft(const QPoint &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 QPoint QRect::topLeft() const    Returns the position of the rectangle's top-left corner.    \sa setTopLeft(), top(), left()*//*!    \fn QPoint QRect::bottomRight() const    Returns the position of the rectangle's bottom-right corner.    Note that for historical reasons this function returns    QPoint(left() + width() -1, top() + height() - 1).    \sa setBottomRight(), bottom(), right()*/