From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/qpoint.html | 378 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 378 insertions(+) create mode 100644 doc/html/qpoint.html (limited to 'doc/html/qpoint.html') diff --git a/doc/html/qpoint.html b/doc/html/qpoint.html new file mode 100644 index 0000000..aa2e5b6 --- /dev/null +++ b/doc/html/qpoint.html @@ -0,0 +1,378 @@ + + + + + +QPoint Class + + + + + + + +
+ +Home + | +All Classes + | +Main Classes + | +Annotated + | +Grouped Classes + | +Functions +

QPoint Class Reference

+ +

The QPoint class defines a point in the plane. +More... +

#include <qpoint.h> +

List of all member functions. +

Public Members

+ +

Related Functions

+ +

Detailed Description

+ + +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. +

See also QPointArray, QSize, QRect, Graphics Classes, and Image Processing Classes. + +

Member Function Documentation

+

QPoint::QPoint () +

+ +

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

QPoint::QPoint ( int xpos, int ypos ) +

+ +

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

bool QPoint::isNull () const +

+ +

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

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 ) +

+ +

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 ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

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

Example: +

+        QPoint p( -1, 4 );
+        p *= 2.5;          // p becomes (-3,10)
+
+ +

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

QPoint & QPoint::operator+= ( const QPoint & p ) +

+ +

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 ) +

+ +

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/= ( int c ) +

+ +

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 ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

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

Example: +

+        QPoint p( -3, 10 );
+        p /= 2.5;           // p becomes (-1,4)
+
+ +

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

QCOORD & QPoint::rx () +

+ +

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)
+
+ +

See also ry(). + +

QCOORD & QPoint::ry () +

+ +

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)
+
+ +

See also rx(). + +

void QPoint::setX ( int x ) +

+ +

Sets the x coordinate of the point to x. +

See also x() and setY(). + +

Example: t14/cannon.cpp. +

void QPoint::setY ( int y ) +

+ +

Sets the y coordinate of the point to y. +

See also y() and setX(). + +

Example: t14/cannon.cpp. +

int QPoint::x () const +

+ +

Returns the x coordinate of the point. +

See also setX() and y(). + +

Examples: canvas/canvas.cpp, chart/canvasview.cpp, dirview/dirview.cpp, fileiconview/qfileiconview.cpp, helpsystem/tooltip.cpp, life/life.cpp, and t14/cannon.cpp. +

int QPoint::y () const +

+ +

Returns the y coordinate of the point. +

See also setY() and x(). + +

Examples: canvas/canvas.cpp, chart/canvasview.cpp, fileiconview/qfileiconview.cpp, helpsystem/tooltip.cpp, life/life.cpp, t14/cannon.cpp, and themes/wood.cpp. +

Related Functions

+

bool operator!= ( const QPoint & p1, const QPoint & p2 ) +

+ +

+

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

const QPoint operator* ( const QPoint & p, int c ) +

+ +

+

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

const QPoint operator* ( int c, const QPoint & p ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

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

const QPoint operator* ( const QPoint & p, double c ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

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* ( double c, const QPoint & p ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

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+ ( const QPoint & p1, const QPoint & p2 ) +

+ +

+

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

const QPoint operator- ( const QPoint & p1, const QPoint & p2 ) +

+ +

+

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

const QPoint operator- ( const QPoint & p ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

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

const QPoint operator/ ( const QPoint & p, int c ) +

+ +

+

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

const QPoint operator/ ( const QPoint & p, double c ) +

+This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +

+

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

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

QDataStream & operator<< ( QDataStream & s, const QPoint & p ) +

+ +

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

See also Format of the QDataStream operators. + +

bool operator== ( const QPoint & p1, const QPoint & p2 ) +

+ +

+

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

QDataStream & operator>> ( QDataStream & s, QPoint & p ) +

+ +

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

See also Format of the QDataStream operators. + + +

+This file is part of the Qt toolkit. +Copyright © 1995-2007 +Trolltech. All Rights Reserved.

+ +
Copyright © 2007 +TrolltechTrademarks +
Qt 3.3.8
+
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