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Diffstat (limited to 'src/kernel/qpoint.cpp')
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diff --git a/src/kernel/qpoint.cpp b/src/kernel/qpoint.cpp new file mode 100644 index 0000000..5313307 --- /dev/null +++ b/src/kernel/qpoint.cpp @@ -0,0 +1,443 @@ +/**************************************************************************** +** +** Implementation of QPoint class +** +** Created : 931028 +** +** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved. +** +** This file is part of the kernel module of the Qt GUI Toolkit. +** +** This file may be used under the terms of the GNU General +** Public License versions 2.0 or 3.0 as published by the Free +** Software Foundation and appearing in the files LICENSE.GPL2 +** and LICENSE.GPL3 included in the packaging of this file. +** Alternatively you may (at your option) use any later version +** of the GNU General Public License if such license has been +** publicly approved by Trolltech ASA (or its successors, if any) +** and the KDE Free Qt Foundation. +** +** Please review the following information to ensure GNU General +** Public Licensing requirements will be met: +** http://trolltech.com/products/qt/licenses/licensing/opensource/. +** If you are unsure which license is appropriate for your use, please +** review the following information: +** http://trolltech.com/products/qt/licenses/licensing/licensingoverview +** or contact the sales department at sales@trolltech.com. +** +** This file may be used under the terms of the Q Public License as +** defined by Trolltech ASA and appearing in the file LICENSE.QPL +** included in the packaging of this file. Licensees holding valid Qt +** Commercial 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 WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted +** herein. +** +**********************************************************************/ + +#include "qpoint.h" +#include "qdatastream.h" + + +/*! + \class QPoint qpoint.h + \brief The QPoint class defines a point in the plane. + + \ingroup images + \ingroup graphics + \mainclass + + A point is specified by an x coordinate and a y coordinate. + + The coordinate type is \c QCOORD (a 32-bit integer). The minimum + value of \c QCOORD is \c QCOORD_MIN (-2147483648) and the maximum + value is \c QCOORD_MAX (2147483647). + + The coordinates are accessed by the functions x() and y(); they + can be set by setX() and setY() or by the reference functions rx() + and ry(). + + Given a point \e p, the following statements are all equivalent: + \code + p.setX( p.x() + 1 ); + p += QPoint( 1, 0 ); + p.rx()++; + \endcode + + A QPoint can also be used as a vector. Addition and subtraction + of QPoints are defined as for vectors (each component is added + separately). You can divide or multiply a QPoint by an \c int or a + \c double. The function manhattanLength() gives an inexpensive + approximation of the length of the QPoint interpreted as a vector. + + Example: + \code + //QPoint oldPos is defined somewhere else + MyWidget::mouseMoveEvent( QMouseEvent *e ) + { + QPoint vector = e->pos() - oldPos; + if ( vector.manhattanLength() > 3 ) + ... //mouse has moved more than 3 pixels since oldPos + } + \endcode + + QPoints can be compared for equality or inequality, and they can + be written to and read from a QStream. + + \sa QPointArray QSize, QRect +*/ + + +/***************************************************************************** + QPoint member functions + *****************************************************************************/ + +/*! + \fn QPoint::QPoint() + + Constructs a point with coordinates (0, 0) (isNull() returns TRUE). +*/ + +/*! + \fn QPoint::QPoint( int xpos, int ypos ) + + Constructs a point with x value \a xpos and y value \a ypos. +*/ + +/*! + \fn bool QPoint::isNull() const + + Returns TRUE if both the x value and the y value are 0; otherwise + returns FALSE. +*/ + +/*! + \fn int QPoint::x() const + + Returns the x coordinate of the point. + + \sa setX() y() +*/ + +/*! + \fn int QPoint::y() const + + Returns the y coordinate of the point. + + \sa setY() x() +*/ + +/*! + \fn void QPoint::setX( int x ) + + Sets the x coordinate of the point to \a x. + + \sa x() setY() +*/ + +/*! + \fn void QPoint::setY( int y ) + + Sets the y coordinate of the point to \a y. + + \sa y() setX() +*/ + + +/*! + \fn QCOORD &QPoint::rx() + + Returns a reference to the x coordinate of the point. + + Using a reference makes it possible to directly manipulate x. + + Example: + \code + QPoint p( 1, 2 ); + p.rx()--; // p becomes (0, 2) + \endcode + + \sa ry() +*/ + +/*! + \fn QCOORD &QPoint::ry() + + Returns a reference to the y coordinate of the point. + + Using a reference makes it possible to directly manipulate y. + + Example: + \code + QPoint p( 1, 2 ); + p.ry()++; // p becomes (1, 3) + \endcode + + \sa rx() +*/ + + +/*! + \fn QPoint &QPoint::operator+=( const QPoint &p ) + + Adds point \a p to this point and returns a reference to this + point. + + Example: + \code + QPoint p( 3, 7 ); + QPoint q( -1, 4 ); + p += q; // p becomes (2,11) + \endcode +*/ + +/*! + \fn QPoint &QPoint::operator-=( const QPoint &p ) + + Subtracts point \a p from this point and returns a reference to + this point. + + Example: + \code + QPoint p( 3, 7 ); + QPoint q( -1, 4 ); + p -= q; // p becomes (4,3) + \endcode +*/ + +/*! + \fn QPoint &QPoint::operator*=( int c ) + + Multiplies this point's x and y by \a c, and returns a reference + to this point. + + Example: + \code + QPoint p( -1, 4 ); + p *= 2; // p becomes (-2,8) + \endcode +*/ + +/*! + \overload QPoint &QPoint::operator*=( double c ) + + Multiplies this point's x and y by \a c, and returns a reference + to this point. + + Example: + \code + QPoint p( -1, 4 ); + p *= 2.5; // p becomes (-3,10) + \endcode + + Note that the result is truncated because points are held as + integers. +*/ + + +/*! + \fn bool operator==( const QPoint &p1, const QPoint &p2 ) + + \relates QPoint + + Returns TRUE if \a p1 and \a p2 are equal; otherwise returns FALSE. +*/ + +/*! + \fn bool operator!=( const QPoint &p1, const QPoint &p2 ) + + \relates QPoint + + Returns TRUE if \a p1 and \a p2 are not equal; otherwise returns FALSE. +*/ + +/*! + \fn const QPoint operator+( const QPoint &p1, const QPoint &p2 ) + + \relates QPoint + + Returns the sum of \a p1 and \a p2; each component is added separately. +*/ + +/*! + \fn const QPoint operator-( const QPoint &p1, const QPoint &p2 ) + + \relates QPoint + + Returns \a p2 subtracted from \a p1; each component is subtracted + separately. +*/ + +/*! + \fn const QPoint operator*( const QPoint &p, int c ) + + \relates QPoint + + Returns the QPoint formed by multiplying both components of \a p + by \a c. +*/ + +/*! + \overload const QPoint operator*( int c, const QPoint &p ) + + \relates QPoint + + Returns the QPoint formed by multiplying both components of \a p + by \a c. +*/ + +/*! + \overload const QPoint operator*( const QPoint &p, double c ) + + \relates QPoint + + Returns the QPoint formed by multiplying both components of \a p + by \a c. + + Note that the result is truncated because points are held as + integers. +*/ + +/*! + \overload const QPoint operator*( double c, const QPoint &p ) + + \relates QPoint + + Returns the QPoint formed by multiplying both components of \a p + by \a c. + + Note that the result is truncated because points are held as + integers. +*/ + +/*! + \overload const QPoint operator-( const QPoint &p ) + + \relates QPoint + + Returns the QPoint formed by changing the sign of both components + of \a p, equivalent to \c{QPoint(0,0) - p}. +*/ + +/*! + \fn QPoint &QPoint::operator/=( int c ) + + Divides both x and y by \a c, and returns a reference to this + point. + + Example: + \code + QPoint p( -2, 8 ); + p /= 2; // p becomes (-1,4) + \endcode +*/ + +/*! + \overload QPoint &QPoint::operator/=( double c ) + + Divides both x and y by \a c, and returns a reference to this + point. + + Example: + \code + QPoint p( -3, 10 ); + p /= 2.5; // p becomes (-1,4) + \endcode + + Note that the result is truncated because points are held as + integers. +*/ + +/*! + \fn const QPoint operator/( const QPoint &p, int c ) + + \relates QPoint + + Returns the QPoint formed by dividing both components of \a p by + \a c. +*/ + +/*! + \overload const QPoint operator/( const QPoint &p, double c ) + + \relates QPoint + + Returns the QPoint formed by dividing both components of \a p + by \a c. + + Note that the result is truncated because points are held as + integers. +*/ + + +void QPoint::warningDivByZero() +{ +#if defined(QT_CHECK_MATH) + qWarning( "QPoint: Division by zero error" ); +#endif +} + + +/***************************************************************************** + QPoint stream functions + *****************************************************************************/ +#ifndef QT_NO_DATASTREAM +/*! + \relates QPoint + + Writes point \a p 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 QPoint &p ) +{ + if ( s.version() == 1 ) + s << (Q_INT16)p.x() << (Q_INT16)p.y(); + else + s << (Q_INT32)p.x() << (Q_INT32)p.y(); + return s; +} + +/*! + \relates QPoint + + Reads a QPoint from the stream \a s into point \a p and returns a + reference to the stream. + + \sa \link datastreamformat.html Format of the QDataStream operators \endlink +*/ + +QDataStream &operator>>( QDataStream &s, QPoint &p ) +{ + if ( s.version() == 1 ) { + Q_INT16 x, y; + s >> x; p.rx() = x; + s >> y; p.ry() = y; + } + else { + Q_INT32 x, y; + s >> x; p.rx() = x; + s >> y; p.ry() = y; + } + return s; +} +#endif // QT_NO_DATASTREAM +/*! + Returns the sum of the absolute values of x() and y(), + traditionally known as the "Manhattan length" of the vector from + the origin to the point. The tradition arises because such + distances apply to travelers who can only travel on a rectangular + grid, like the streets of Manhattan. + + This is a useful, and quick to calculate, approximation to the + true length: sqrt(pow(x(),2)+pow(y(),2)). +*/ +int QPoint::manhattanLength() const +{ + return QABS(x())+QABS(y()); +} |