---
name: "QwtCompassMagnetNeedle"
section: "3"
platform: "linux"
package: "libqwt-doc"
version: "6.1.4-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/QwtCompassMagnetNeedle"
---

# QwtCompassMagnetNeedle(3)

A magnet needle for compass widgets.

## NAME

QwtCompassMagnetNeedle - A magnet needle for compass widgets.

## SYNOPSIS

`#include <qwt_dial_needle.h>`

Inherits **QwtDialNeedle**.

### Public Types

enum **Style** { **TriangleStyle**, **ThinStyle** }\
 Style of the needle.

### Public Member Functions

**QwtCompassMagnetNeedle** (**Style**=**TriangleStyle**, const QColor &light=Qt::white, const QColor &dark=Qt::red)\
 Constructor.

### Protected Member Functions

virtual void **drawNeedle** (QPainter \*, double length, QPalette::ColorGroup) const\

## Detailed Description

A magnet needle for compass widgets.

A magnet needle points to two opposite directions indicating north and south.

The following colors are used:

- •

  QPalette::Light\
  \
    Used for pointing south

- •

  QPalette::Dark\
  \
    Used for pointing north

- •

  QPalette::Base\
  \
    Knob (ThinStyle only)

**See also:**

**QwtDial**, **QwtCompass**

## Member Enumeration Documentation

### enum QwtCompassMagnetNeedle::Style

Style of the needle.

**Enumerator**

- *TriangleStyle*

  *A needle with a triangular shape.*

- *ThinStyle*

  *A thin needle.*

## Member Function Documentation

### void QwtCompassMagnetNeedle::drawNeedle (QPainter \* painter, double length, QPalette::ColorGroup colorGroup) const` [protected]`, ` [virtual]`

*Draw the needle*

**Parameters:**

*painter Painter* \
 *length Length of the needle* \
 *colorGroup Color group, used for painting*

*Implements* **QwtDialNeedle***.*

## Author

*Generated automatically by Doxygen for Qwt User's Guide from the source code.*