source: trunk/src/kernel/qrect.cpp@ 94

/****************************************************************************
** $Id: qrect.cpp 2 2005-11-16 15:49:26Z dmik $
**
** Implementation of QRect class
**
** Created : 931028
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
**********************************************************************/

#define  QRECT_C
#include "qrect.h"
#include "qdatastream.h"

/*!
    \class QRect
    \brief The QRect class defines a rectangle in the plane.

    \ingroup images
    \ingroup graphics
    \mainclass

    A rectangle is internally represented as an upper-left corner and
    a bottom-right corner, but it is normally expressed as an
    upper-left corner and a size.

    The coordinate type is QCOORD (defined in \c qwindowdefs.h as \c
    int). The minimum value of QCOORD is QCOORD_MIN (-2147483648) and
    the maximum value is  QCOORD_MAX (2147483647).

    Note that the size (width and height) of a rectangle might be
    different from what you are used to. If the top-left corner and
    the bottom-right corner are the same, the height and the width of
    the rectangle will both be 1.

    Generally, \e{width = right - left + 1} and \e{height = bottom -
    top + 1}. We designed it this way to make it correspond to
    rectangular spaces used by drawing functions in which the width
    and height denote a number of pixels. For example, drawing a
    rectangle with width and height 1 draws a single pixel.

    The default coordinate system has origin (0, 0) in the top-left
    corner. The positive direction of the y axis is down, and the
    positive x axis is from left to right.

    A QRect can be constructed with a set of left, top, width and
    height integers, from two QPoints or from a QPoint and a QSize.
    After creation the dimensions can be changed, e.g. with setLeft(),
    setRight(), setTop() and setBottom(), or by setting sizes, e.g.
    setWidth(), setHeight() and setSize(). The dimensions can also be
    changed with the move functions, e.g. moveBy(), moveCenter(),
    moveBottomRight(), etc. You can also add coordinates to a
    rectangle with addCoords().

    You can test to see if a QRect contains a specific point with
    contains(). You can also test to see if two QRects intersect with
    intersects() (see also intersect()). To get the bounding rectangle
    of two QRects use unite().

    \sa QPoint, QSize
*/


/*****************************************************************************
  QRect member functions
 *****************************************************************************/

/*!
    \fn QRect::QRect()

    Constructs an invalid rectangle.
*/

/*!
    Constructs a rectangle with \a topLeft as the top-left corner and
    \a bottomRight as the bottom-right corner.
*/

QRect::QRect( const QPoint &topLeft, const QPoint &bottomRight )
{
    x1 = (QCOORD)topLeft.x();
    y1 = (QCOORD)topLeft.y();
    x2 = (QCOORD)bottomRight.x();
    y2 = (QCOORD)bottomRight.y();
}

/*!
    Constructs a rectangle with \a topLeft as the top-left corner and
    \a size as the rectangle size.
*/

QRect::QRect( const QPoint &topLeft, const QSize &size )
{
    x1 = (QCOORD)topLeft.x();
    y1 = (QCOORD)topLeft.y();
    x2 = (QCOORD)(x1+size.width()-1);
    y2 = (QCOORD)(y1+size.height()-1);
}

/*!
    \fn QRect::QRect( int left, int top, int width, int height )

    Constructs a rectangle with the \a top, \a left corner and \a
    width and \a height.

    Example (creates three identical rectangles):
    \code
        QRect r1( QPoint(100,200), QPoint(110,215) );
        QRect r2( QPoint(100,200), QSize(11,16) );
        QRect r3( 100, 200, 11, 16 );
    \endcode
*/


/*!
    \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, that
    is right() == left() - 1 and bottom() == top() - 1.

    Note that if right() == left() and bottom() == top(), then the
    rectangle has width 1 and height 1.

    A null rectangle is also empty.

    A null rectangle 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. \c{isEmpty() == !isValid()}

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

/*!
    \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.

    \c{isValid() == !isEmpty()}

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


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

    It swaps left and right if left() \> right(), and swaps top and
    bottom if top() \> bottom().

    \sa isValid()
*/

QRect QRect::normalize() const
{
    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 int QRect::left() const

    Returns the left coordinate of the rectangle. Identical to x().

    \sa setLeft(), right(), topLeft(), bottomLeft()
*/

/*!
    \fn int QRect::top() const

    Returns the top coordinate of the rectangle. Identical to y().

    \sa setTop(), bottom(), topLeft(), topRight()
*/

/*!
    \fn int QRect::right() const

    Returns the right coordinate of the rectangle.

    \sa setRight(), left(), topRight(), bottomRight()
*/

/*!
    \fn int QRect::bottom() const

    Returns the bottom coordinate of the rectangle.

    \sa setBottom(), top(), bottomLeft(), bottomRight()
*/

/*!
    \fn QCOORD &QRect::rLeft()

    Returns a reference to the left coordinate of the rectangle.

    \sa rTop(), rRight(), rBottom()
*/

/*!
    \fn QCOORD &QRect::rTop()

    Returns a reference to the top coordinate of the rectangle.

    \sa rLeft(),  rRight(), rBottom()
*/

/*!
    \fn QCOORD &QRect::rRight()

    Returns a reference to the right coordinate of the rectangle.

    \sa rLeft(), rTop(), rBottom()
*/

/*!
    \fn QCOORD &QRect::rBottom()

    Returns a reference to the bottom coordinate of the rectangle.

    \sa rLeft(), rTop(), rRight()
*/

/*!
    \fn int QRect::x() const

    Returns the left coordinate of the rectangle. Identical to left().

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

/*!
    \fn int QRect::y() const

    Returns the top coordinate of the rectangle. Identical to top().

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

/*!
    \fn void QRect::setLeft( int pos )

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

    Identical to setX().

    \sa left(), setTop(), setWidth()
*/

/*!
    \fn void QRect::setTop( int pos )

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

    Identical to setY().

    \sa top(), setBottom(), setHeight()
*/

/*!
    \fn void QRect::setRight( int pos )

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

    \sa right(), setLeft(), setWidth()
*/

/*!
    \fn void QRect::setBottom( int pos )

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

    \sa bottom(), setTop(), setHeight()
*/

/*!
    \fn void QRect::setX( int x )

    Sets the x position of the rectangle (its left end) to \a x. May
    change the width, but will never change the right edge of the
    rectangle.

    Identical to setLeft().

    \sa x(), setY()
*/

/*!
    \fn void QRect::setY( int y )

    Sets the y position of the rectangle (its top) to \a y. May change
    the height, but will never change the bottom edge of the
    rectangle.

    Identical to setTop().

    \sa y(), setX()
*/

/*!
    Set the top-left corner of the rectangle to \a p. May change
    the size, but will the never change the bottom-right corner of
    the rectangle.

    \sa topLeft(), moveTopLeft(), setBottomRight(), setTopRight(), setBottomLeft()
*/
void QRect::setTopLeft( const QPoint &p )
{
    setLeft( p.x() );
    setTop( p.y() );
}

/*!
    Set the bottom-right corner of the rectangle to \a p. May change
    the size, but will the never change the top-left corner of
    the rectangle.

    \sa bottomRight(), moveBottomRight(), setTopLeft(), setTopRight(), setBottomLeft()
*/
void QRect::setBottomRight( const QPoint &p )
{
    setRight( p.x() );
    setBottom( p.y() );
}

/*!
    Set the top-right corner of the rectangle to \a p. May change
    the size, but will the never change the bottom-left corner of
    the rectangle.

    \sa topRight(), moveTopRight(), setTopLeft(), setBottomRight(), setBottomLeft()
*/
void QRect::setTopRight( const QPoint &p )
{
    setRight( p.x() );
    setTop( p.y() );
}

/*!
    Set the bottom-left corner of the rectangle to \a p. May change
    the size, but will the never change the top-right corner of
    the rectangle.

    \sa bottomLeft(), moveBottomLeft(), setTopLeft(), setBottomRight(), setTopRight()
*/
void QRect::setBottomLeft( const QPoint &p )
{
    setLeft( p.x() );
    setBottom( p.y() );
}

/*!
    \fn QPoint QRect::topLeft() const

    Returns the top-left position of the rectangle.

    \sa setTopLeft(), moveTopLeft(), bottomRight(), left(), top()
*/

/*!
    \fn QPoint QRect::bottomRight() const

    Returns the bottom-right position of the rectangle.

    \sa setBottomRight(), moveBottomRight(), topLeft(), right(), bottom()
*/

/*!
    \fn QPoint QRect::topRight() const

    Returns the top-right position of the rectangle.

    \sa setTopRight(), moveTopRight(), bottomLeft(), top(), right()
*/

/*!
    \fn QPoint QRect::bottomLeft() const

    Returns the bottom-left position of the rectangle.

    \sa setBottomLeft(), moveBottomLeft(), topRight(), bottom(), left()
*/

/*!
    \fn QPoint QRect::center() const

    Returns the center point of the rectangle.

    \sa moveCenter(), topLeft(), bottomRight(), topRight(), bottomLeft()
*/


/*!
    Extracts the rectangle parameters as the position \a *x, \a *y and
    width \a *w and height \a *h.

    \sa setRect(), coords()
*/

void QRect::rect( int *x, int *y, int *w, int *h ) const
{
    *x = x1;
    *y = y1;
    *w = x2-x1+1;
    *h = y2-y1+1;
}

/*!
    Extracts the rectangle parameters as the top-left point \a *xp1,
    \a *yp1 and the bottom-right point \a *xp2, \a *yp2.

    \sa setCoords(), rect()
*/

void QRect::coords( int *xp1, int *yp1, int *xp2, int *yp2 ) const
{
    *xp1 = x1;
    *yp1 = y1;
    *xp2 = x2;
    *yp2 = y2;
}


/*!
    Sets the left position of the rectangle to \a pos, leaving the
    size unchanged.

    \sa left(), setLeft(), moveTop(), moveRight(), moveBottom()
*/
void QRect::moveLeft( int pos )
{
    x2 += (QCOORD)(pos - x1);
    x1 = (QCOORD)pos;
}

/*!
    Sets the top position of the rectangle to \a pos, leaving the
    size unchanged.

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

void QRect::moveTop( int pos )
{
    y2 += (QCOORD)(pos - y1);
    y1 = (QCOORD)pos;
}

/*!
    Sets the right position of the rectangle to \a pos, leaving the
    size unchanged.

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

void QRect::moveRight( int pos )
{
    x1 += (QCOORD)(pos - x2);
    x2 = (QCOORD)pos;
}

/*!
    Sets the bottom position of the rectangle to \a pos, leaving the
    size unchanged.

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

void QRect::moveBottom( int pos )
{
    y1 += (QCOORD)(pos - y2);
    y2 = (QCOORD)pos;
}

/*!
    Sets the top-left position of the rectangle to \a p, leaving the
    size unchanged.

    \sa topLeft(), setTopLeft(), moveBottomRight(), moveTopRight(), moveBottomLeft()
*/

void QRect::moveTopLeft( const QPoint &p )
{
    moveLeft( p.x() );
    moveTop( p.y() );
}

/*!
    Sets the bottom-right position of the rectangle to \a p, leaving
    the size unchanged.

    \sa bottomRight(), setBottomRight(), moveTopLeft(), moveTopRight(), moveBottomLeft()
*/

void QRect::moveBottomRight( const QPoint &p )
{
    moveRight( p.x() );
    moveBottom( p.y() );
}

/*!
    Sets the top-right position of the rectangle to \a p, leaving the
    size unchanged.

    \sa topRight(), setTopRight(), moveTopLeft(), moveBottomRight(), moveBottomLeft()
*/

void QRect::moveTopRight( const QPoint &p )
{
    moveRight( p.x() );
    moveTop( p.y() );
}

/*!
    Sets the bottom-left position of the rectangle to \a p, leaving
    the size unchanged.

    \sa bottomLeft(), setBottomLeft(), moveTopLeft(), moveBottomRight(), moveTopRight()
*/

void QRect::moveBottomLeft( const QPoint &p )
{
    moveLeft( p.x() );
    moveBottom( p.y() );
}


/*!
    Sets the center point of the rectangle to \a p, leaving the size
    unchanged.

    \sa center(), moveTopLeft(), moveBottomRight(), moveTopRight(), moveBottomLeft()
*/

void QRect::moveCenter( const QPoint &p )
{
    QCOORD w = x2 - x1;
    QCOORD h = y2 - y1;
    x1 = (QCOORD)(p.x() - w/2);
    y1 = (QCOORD)(p.y() - h/2);
    x2 = x1 + w;
    y2 = y1 + h;
}


/*!
    Moves the rectangle \a dx along the x axis and \a dy along the y
    axis, relative to the current position. Positive values move the
    rectangle to the right and down.

    \sa moveTopLeft()
*/

void QRect::moveBy( int dx, int dy )
{
    x1 += (QCOORD)dx;
    y1 += (QCOORD)dy;
    x2 += (QCOORD)dx;
    y2 += (QCOORD)dy;
}

/*!
    Sets the coordinates of the rectangle's top-left corner to \a (x,
    y), and its size to \a (w, h).

    \sa rect(), setCoords()
*/

void QRect::setRect( int x, int y, int w, int h )
{
    x1 = (QCOORD)x;
    y1 = (QCOORD)y;
    x2 = (QCOORD)(x+w-1);
    y2 = (QCOORD)(y+h-1);
}

/*!
    Sets the coordinates of the rectangle's top-left corner to \a
    (xp1, yp1), and the coordinates of its bottom-right corner to \a
    (xp2, yp2).

    \sa coords(), setRect()
*/

void QRect::setCoords( int xp1, int yp1, int xp2, int yp2 )
{
    x1 = (QCOORD)xp1;
    y1 = (QCOORD)yp1;
    x2 = (QCOORD)xp2;
    y2 = (QCOORD)yp2;
}

/*!
    Adds \a xp1, \a yp1, \a xp2 and \a yp2 respectively to the
    existing coordinates of the rectangle.
*/

void QRect::addCoords( int xp1, int yp1, int xp2, int yp2 )
{
    x1 += (QCOORD)xp1;
    y1 += (QCOORD)yp1;
    x2 += (QCOORD)xp2;
    y2 += (QCOORD)yp2;
}

/*!
    \fn QSize QRect::size() const

    Returns the size of the rectangle.

    \sa width(), height()
*/

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

    Returns the width of the rectangle. The width includes both the
    left and right edges, i.e. width = right - left + 1.

    \sa height(), size(), setHeight()
*/

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

    Returns the height of the rectangle. The height includes both the
    top and bottom edges, i.e. height = bottom - top + 1.

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

/*!
    Sets the width of the rectangle to \a w. The right edge is
    changed, but not the left edge.

    \sa width(), setLeft(), setRight(), setSize()
*/

void QRect::setWidth( int w )
{
    x2 = (QCOORD)(x1 + w - 1);
}

/*!
    Sets the height of the rectangle to \a h. The top edge is not
    moved, but the bottom edge may be moved.

    \sa height(), setTop(), setBottom(), setSize()
*/

void QRect::setHeight( int h )
{
    y2 = (QCOORD)(y1 + h - 1);
}

/*!
    Sets the size of the rectangle to \a s. The top-left corner is not
    moved.

    \sa size(), setWidth(), setHeight()
*/

void QRect::setSize( const QSize &s )
{
    x2 = (QCOORD)(s.width() +x1-1);
    y2 = (QCOORD)(s.height()+y1-1);
}

/*!
    Returns TRUE if the point \a p is inside or on the edge of the
    rectangle; otherwise returns FALSE.

    If \a proper is TRUE, this function returns TRUE only if \a p is
    inside (not on the edge).
*/

bool QRect::contains( const QPoint &p, bool proper ) const
{
    if ( proper )
        return p.x() > x1 && p.x() < x2 &&
               p.y() > y1 && p.y() < y2;
    else
        return p.x() >= x1 && p.x() <= x2 &&
               p.y() >= y1 && p.y() <= y2;
}

/*!
    \overload bool QRect::contains( int x, int y, bool proper ) const

    Returns TRUE if the point \a x, \a y is inside this rectangle;
    otherwise returns FALSE.

    If \a proper is TRUE, this function returns TRUE only if the point
    is entirely inside (not on the edge).
*/

/*!
    \overload bool QRect::contains( int x, int y ) const

    Returns TRUE if the point \a x, \a y is inside this rectangle;
    otherwise returns FALSE.
*/

/*!
    \overload

    Returns TRUE if the rectangle \a r is inside this rectangle;
    otherwise returns FALSE.

    If \a proper is TRUE, this function returns TRUE only if \a r is
    entirely inside (not on the edge).

    \sa unite(), intersect(), intersects()
*/

bool QRect::contains( const QRect &r, bool proper ) const
{
    if ( proper )
        return r.x1 > x1 && r.x2 < x2 && r.y1 > y1 && r.y2 < y2;
    else
        return r.x1 >= x1 && r.x2 <= x2 && r.y1 >= y1 && r.y2 <= y2;
}

/*!
    Unites this rectangle with rectangle \a r.
*/
QRect& QRect::operator|=(const QRect &r)
{
    *this = *this | r;
    return *this;
}

/*!
    Intersects this rectangle with rectangle \a r.
*/
QRect& QRect::operator&=(const QRect &r)
{
    *this = *this & r;
    return *this;
}


/*!
    Returns the bounding rectangle of this rectangle and rectangle \a
    r.

    The bounding rectangle of a nonempty rectangle and an empty or
    invalid rectangle is defined to be the nonempty rectangle.

    \sa operator|=(), operator&(), intersects(), contains()
*/

QRect QRect::operator|(const QRect &r) const
{
    if ( isValid() ) {
        if ( r.isValid() ) {
            QRect tmp;
            tmp.setLeft(   QMIN( x1, r.x1 ) );
            tmp.setRight(  QMAX( x2, r.x2 ) );
            tmp.setTop(    QMIN( y1, r.y1 ) );
            tmp.setBottom( QMAX( y2, r.y2 ) );
            return tmp;
        } else {
            return *this;
        }
    } else {
        return r;
    }
}

/*!
    Returns the bounding rectangle of this rectangle and rectangle \a
    r. \c{r.unite(s)} is equivalent to \c{r|s}.
*/
QRect QRect::unite( const QRect &r ) const
{
    return *this | r;
}


/*!
    Returns the intersection of this rectangle and rectangle \a r.

    Returns an empty rectangle if there is no intersection.

    \sa operator&=(), operator|(), isEmpty(), intersects(), contains()
*/

QRect QRect::operator&( const QRect &r ) const
{
    QRect tmp;
    tmp.x1 = QMAX( x1, r.x1 );
    tmp.x2 = QMIN( x2, r.x2 );
    tmp.y1 = QMAX( y1, r.y1 );
    tmp.y2 = QMIN( y2, r.y2 );
    return tmp;
}

/*!
    Returns the intersection of this rectangle and rectangle \a r.
    \c{r.intersect(s)} is equivalent to \c{r&s}.
*/
QRect QRect::intersect( const QRect &r ) const
{
    return *this & r;
}

/*!
    Returns TRUE if this rectangle intersects with rectangle \a r
    (there is at least one pixel that is within both rectangles);
    otherwise returns FALSE.

    \sa intersect(), contains()
*/

bool QRect::intersects( const QRect &r ) const
{
    return ( QMAX( x1, r.x1 ) <= QMIN( x2, r.x2 ) &&
             QMAX( y1, r.y1 ) <= QMIN( y2, r.y2 ) );
}


/*!
    \relates QRect

    Returns TRUE if \a r1 and \a r2 are equal; otherwise returns FALSE.
*/

bool operator==( const QRect &r1, const QRect &r2 )
{
    return r1.x1==r2.x1 && r1.x2==r2.x2 && r1.y1==r2.y1 && r1.y2==r2.y2;
}

/*!
    \relates QRect

    Returns TRUE if \a r1 and \a r2 are different; otherwise returns FALSE.
*/

bool operator!=( const QRect &r1, const QRect &r2 )
{
    return r1.x1!=r2.x1 || r1.x2!=r2.x2 || r1.y1!=r2.y1 || r1.y2!=r2.y2;
}


/*****************************************************************************
  QRect stream functions
 *****************************************************************************/
#ifndef QT_NO_DATASTREAM
/*!
    \relates QRect

    Writes the QRect, \a r, to the stream \a s, and returns a
    reference to the stream.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator<<( QDataStream &s, const QRect &r )
{
    if ( s.version() == 1 )
        s << (Q_INT16)r.left() << (Q_INT16)r.top()
          << (Q_INT16)r.right() << (Q_INT16)r.bottom();
    else
        s << (Q_INT32)r.left() << (Q_INT32)r.top()
          << (Q_INT32)r.right() << (Q_INT32)r.bottom();
    return s;
}

/*!
    \relates QRect

    Reads a QRect from the stream \a s into rect \a r and returns a
    reference to the stream.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/

QDataStream &operator>>( QDataStream &s, QRect &r )
{
    if ( s.version() == 1 ) {
        Q_INT16 x1, y1, x2, y2;
        s >> x1; s >> y1; s >> x2; s >> y2;
        r.setCoords( x1, y1, x2, y2 );
    }
    else {
        Q_INT32 x1, y1, x2, y2;
        s >> x1; s >> y1; s >> x2; s >> y2;
        r.setCoords( x1, y1, x2, y2 );
    }
    return s;
}
#endif // QT_NO_DATASTREAM