Referencia de la Clase QPoint

The QPoint class defines a point in the plane. Más...

#include <qpoint.h>

Lista de todos los miembros.

Métodos públicos
	QPoint ()
	QPoint (int xpos, int ypos)
bool	isNull () const
int	x () const
int	y () const
void	setX (int x)
void	setY (int y)
int	manhattanLength () const
QCOORD &	rx ()
QCOORD &	ry ()
QPoint &	operator+= (const QPoint &p)
QPoint &	operator-= (const QPoint &p)
QPoint &	operator*= (int c)
QPoint &	operator*= (double c)
QPoint &	operator/= (int c)
QPoint &	operator/= (double c)
	QPoint ()
	QPoint (int xpos, int ypos)
bool	isNull () const
int	x () const
int	y () const
void	setX (int x)
void	setY (int y)
int	manhattanLength () const
QCOORD &	rx ()
QCOORD &	ry ()
QPoint &	operator+= (const QPoint &p)
QPoint &	operator-= (const QPoint &p)
QPoint &	operator*= (int c)
QPoint &	operator*= (double c)
QPoint &	operator/= (int c)
QPoint &	operator/= (double c)
Amigas
bool	operator== (const QPoint &, const QPoint &)
bool	operator!= (const QPoint &, const QPoint &)
const QPoint	operator+ (const QPoint &, const QPoint &)
const QPoint	operator- (const QPoint &, const QPoint &)
const QPoint	operator* (const QPoint &, int)
const QPoint	operator* (int, const QPoint &)
const QPoint	operator* (const QPoint &, double)
const QPoint	operator* (double, const QPoint &)
const QPoint	operator- (const QPoint &)
const QPoint	operator/ (const QPoint &, int)
const QPoint	operator/ (const QPoint &, double)
bool	operator== (const QPoint &, const QPoint &)
bool	operator!= (const QPoint &, const QPoint &)
const QPoint	operator+ (const QPoint &, const QPoint &)
const QPoint	operator- (const QPoint &, const QPoint &)
const QPoint	operator* (const QPoint &, int)
const QPoint	operator* (int, const QPoint &)
const QPoint	operator* (const QPoint &, double)
const QPoint	operator* (double, const QPoint &)
const QPoint	operator- (const QPoint &)
const QPoint	operator/ (const QPoint &, int)
const QPoint	operator/ (const QPoint &, double)
Funciones relacionadas
(Observar que estas no son funciones miembro.)
const QPoint	operator
const QPoint	operator
const QPoint	operator
const QPoint	operator
const QPoint	operator
QDataStream &	operator<< (QDataStream &s, const QPoint &p)
QDataStream &	operator>> (QDataStream &s, QPoint &p)

---

Descripción detallada

The QPoint class defines a point in the plane.

A point is specified by an x coordinate and a y coordinate.

The coordinate type is QCOORD (a 32-bit integer). The minimum value of QCOORD is QCOORD_MIN (-2147483648) and the maximum value is 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 p, the following statements are all equivalent:

        p.setX( p.x() + 1 );
        p += QPoint( 1, 0 );
        p.rx()++;

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 int or a double. The function manhattanLength() gives an inexpensive approximation of the length of the QPoint interpreted as a vector.

Example:

        //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
        }

QPoints can be compared for equality or inequality, and they can be written to and read from a QStream.

Ver también:

QPointArray QSize, QRect

---

Documentación del constructor y destructor

QPoint::QPoint

(

)

[inline]

Constructs a point with coordinates (0, 0) (isNull() returns TRUE).

QPoint::QPoint	(	int	xpos,
		int	ypos
	)		[inline]

Constructs a point with x value xpos and y value ypos.

QPoint::QPoint

(

)

QPoint::QPoint	(	int	xpos,
		int	ypos
	)

---

Documentación de las funciones miembro

bool QPoint::isNull

(

)

const [inline]

Returns TRUE if both the x value and the y value are 0; otherwise returns FALSE.

bool QPoint::isNull

(

)

const

int QPoint::manhattanLength

(

)

const

int QPoint::manhattanLength

(

)

const

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)).

QPoint & QPoint::operator*=

(

int

c

)

[inline]

Multiplies this point's x and y by c, and returns a reference to this point.

Example:

        QPoint p( -1, 4 );
        p *= 2;            // p becomes (-2,8)

QPoint & QPoint::operator*=

(

double

c

)

[inline]

QPoint& QPoint::operator*=

(

int

c

)

QPoint& QPoint::operator*=

(

double

c

)

QPoint & QPoint::operator+=

(

const QPoint &

p

)

[inline]

Adds point p to this point and returns a reference to this point.

Example:

        QPoint p(  3, 7 );
        QPoint q( -1, 4 );
        p += q;            // p becomes (2,11)

QPoint& QPoint::operator+=

(

const QPoint &

p

)

QPoint & QPoint::operator-=

(

const QPoint &

p

)

[inline]

Subtracts point p from this point and returns a reference to this point.

Example:

        QPoint p(  3, 7 );
        QPoint q( -1, 4 );
        p -= q;            // p becomes (4,3)

QPoint& QPoint::operator-=

(

const QPoint &

p

)

QPoint& QPoint::operator/=

(

int

c

)

QPoint & QPoint::operator/=

(

int

c

)

[inline]

Divides both x and y by c, and returns a reference to this point.

Example:

        QPoint p( -2, 8 );
        p /= 2;            // p becomes (-1,4)

QPoint& QPoint::operator/=

(

double

c

)

QPoint & QPoint::operator/=

(

double

c

)

[inline]

QCOORD& QPoint::rx

(

)

QCOORD & QPoint::rx

(

)

[inline]

Returns a reference to the x coordinate of the point.

Using a reference makes it possible to directly manipulate x.

Example:

        QPoint p( 1, 2 );
        p.rx()--;         // p becomes (0, 2)

Ver también:

ry()

QCOORD & QPoint::ry

(

)

[inline]

Returns a reference to the y coordinate of the point.

Using a reference makes it possible to directly manipulate y.

Example:

        QPoint p( 1, 2 );
        p.ry()++;         // p becomes (1, 3)

Ver también:

rx()

QCOORD& QPoint::ry

(

)

void QPoint::setX

(

int

x

)

[inline]

Sets the x coordinate of the point to x.

Ver también:

x() setY()

void QPoint::setX

(

int

x

)

void QPoint::setY

(

int

y

)

void QPoint::setY

(

int

y

)

[inline]

Sets the y coordinate of the point to y.

Ver también:

y() setX()

int QPoint::x

(

)

const [inline]

Returns the x coordinate of the point.

Ver también:

setX() y()

int QPoint::x

(

)

const

int QPoint::y

(

)

const

int QPoint::y

(

)

const [inline]

Returns the y coordinate of the point.

Ver también:

setY() x()

---

Documentación de las funciones relacionadas y clases amigas

const QPoint operator [related]

Returns the QPoint formed by multiplying both components of p by c.

const QPoint operator [related]

Returns the QPoint formed by multiplying both components of p by c.

Note that the result is truncated because points are held as integers.

const QPoint operator [related]

Returns the QPoint formed by multiplying both components of p by c.

Note that the result is truncated because points are held as integers.

const QPoint operator [related]

Returns the QPoint formed by changing the sign of both components of p, equivalent to {QPoint(0,0) - p}.

const QPoint operator [related]

Returns the QPoint formed by dividing both components of p by c.

Note that the result is truncated because points are held as integers.

bool operator!=	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

Returns TRUE if p1 and p2 are not equal; otherwise returns FALSE.

bool operator!=	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

const QPoint operator*	(	double	c,
		const QPoint &	p
	)		[friend]

const QPoint operator*	(	const QPoint &	p,
		int	c
	)		[friend]

const QPoint operator*	(	int	c,
		const QPoint &	p
	)		[friend]

const QPoint operator*	(	const QPoint &	p,
		double	c
	)		[friend]

const QPoint operator*	(	double	c,
		const QPoint &	p
	)		[friend]

const QPoint operator*	(	const QPoint &	p,
		int	c
	)		[friend]

Returns the QPoint formed by multiplying both components of p by c.

const QPoint operator*	(	int	c,
		const QPoint &	p
	)		[friend]

const QPoint operator*	(	const QPoint &	p,
		double	c
	)		[friend]

const QPoint operator+	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

Returns the sum of p1 and p2; each component is added separately.

const QPoint operator+	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

const QPoint operator-

(

const QPoint &

p

)

[friend]

const QPoint operator-

(

const QPoint &

p

)

[friend]

const QPoint operator-	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

Returns p2 subtracted from p1; each component is subtracted separately.

const QPoint operator-	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

const QPoint operator/	(	const QPoint &	p,
		int	c
	)		[friend]

Returns the QPoint formed by dividing both components of p by c.

const QPoint operator/	(	const QPoint &	p,
		int	c
	)		[friend]

const QPoint operator/	(	const QPoint &	p,
		double	c
	)		[friend]

const QPoint operator/	(	const QPoint &	p,
		double	c
	)		[friend]

QDataStream & operator<<	(	QDataStream &	s,
		const QPoint &	p
	)		[related]

Writes point p to the stream s and returns a reference to the stream.

Ver también:

Format of the QDataStream operators

bool operator==	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

bool operator==	(	const QPoint &	p1,
		const QPoint &	p2
	)		[friend]

Returns TRUE if p1 and p2 are equal; otherwise returns FALSE.

QDataStream & operator>>	(	QDataStream &	s,
		QPoint &	p
	)		[related]

Reads a QPoint from the stream s into point p and returns a reference to the stream.

Ver también:

Format of the QDataStream operators

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La documentación para esta clase fue generada a partir de los siguientes ficheros:

• src/qt/include/qpoint.h
• src/qt/src/kernel/qpoint.h
• src/qt/src/kernel/qpoint.cpp