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QwtCompass(3) Qwt User's Guide QwtCompass(3)


QwtCompass - A Compass Widget.


#include <qwt_compass.h>

Inherits QwtDial.

Public Member Functions

QwtCompass (QWidget *parent=NULL)
Constructor. virtual ~QwtCompass ()
Destructor. void setRose (QwtCompassRose *rose)
const QwtCompassRose * rose () const
QwtCompassRose * rose ()

Protected Member Functions

virtual void drawRose (QPainter *, const QPointF &center, double radius, double north, QPalette::ColorGroup) const
virtual void drawScaleContents (QPainter *, const QPointF &center, double radius) const override
virtual void keyPressEvent (QKeyEvent *) override

Additional Inherited Members

Detailed Description

A Compass Widget.

QwtCompass is a widget to display and enter directions. It consists of a scale, an optional needle and rose.


The examples/dials example shows how to use QwtCompass.

Definition at line 61 of file qwt_compass.h.

Constructor & Destructor Documentation

QwtCompass::QwtCompass (QWidget * parent = NULL) [explicit]



parent Parent widget

Create a compass widget with a scale, no needle and no rose. The default origin is 270.0 with no valid value. It accepts mouse and keyboard inputs and has no step size. The default mode is QwtDial::RotateNeedle.

Definition at line 158 of file qwt_compass.cpp.

Member Function Documentation

void QwtCompass::drawRose (QPainter * painter, const QPointF & center, double radius, double north, QPalette::ColorGroup cg) const [protected], [virtual]

Draw the compass rose


painter Painter
center Center of the compass
radius of the circle, where to paint the rose
north Direction pointing north, in degrees counter clockwise
cg Color group

Definition at line 218 of file qwt_compass.cpp.

void QwtCompass::drawScaleContents (QPainter * painter, const QPointF & center, double radius) const [override], [protected], [virtual]

Draw the contents of the scale


painter Painter
center Center of the content circle
radius Radius of the content circle

Reimplemented from QwtDial.

Definition at line 189 of file qwt_compass.cpp.

void QwtCompass::keyPressEvent (QKeyEvent * kev) [override], [protected], [virtual]

Handles key events

Beside the keys described in QwtDial::keyPressEvent numbers from 1-9 (without 5) set the direction according to their position on the num pad.

See also


Reimplemented from QwtAbstractSlider.

Definition at line 271 of file qwt_compass.cpp.

QwtCompassRose * QwtCompass::rose ()



See also


Definition at line 257 of file qwt_compass.cpp.

const QwtCompassRose * QwtCompass::rose () const



See also


Definition at line 248 of file qwt_compass.cpp.

void QwtCompass::setRose (QwtCompassRose * rose)

Set a rose for the compass


rose Compass rose


The rose will be deleted, when a different rose is set or in ~QwtCompass

See also


Definition at line 232 of file qwt_compass.cpp.


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Sun Jul 18 2021 Version 6.2.0