QwtRoundScaleDraw Class Reference

#include <qwt_round_scale_draw.h>

Inheritance diagram for QwtRoundScaleDraw:

List of all members.

Public Member Functions
	QwtRoundScaleDraw ()
virtual	~QwtRoundScaleDraw ()
QPointF	center () const
virtual double	extent (const QFont &) const
void	moveCenter (double x, double y)
void	moveCenter (const QPointF &)
int	radius () const
void	setAngleRange (double angle1, double angle2)
void	setRadius (int radius)
Public Member Functions inherited from QwtAbstractScaleDraw
	QwtAbstractScaleDraw ()
virtual	~QwtAbstractScaleDraw ()
virtual void	draw (QPainter *, const QPalette &) const
void	enableComponent (ScaleComponent, bool enable=true)
bool	hasComponent (ScaleComponent) const
virtual QwtText	label (double) const
double	maxTickLength () const
double	minimumExtent () const
int	penWidth () const
const QwtScaleDiv &	scaleDiv () const
const QwtScaleMap &	scaleMap () const
QwtScaleMap &	scaleMap ()
void	setMinimumExtent (double)
void	setPenWidth (int width)
void	setScaleDiv (const QwtScaleDiv &s)
void	setSpacing (double margin)
void	setTickLength (QwtScaleDiv::TickType, double length)
void	setTransformation (QwtScaleTransformation *)
double	spacing () const
double	tickLength (QwtScaleDiv::TickType) const

Protected Member Functions
virtual void	drawBackbone (QPainter *p) const
virtual void	drawLabel (QPainter *p, double val) const
virtual void	drawTick (QPainter *p, double val, double len) const
Protected Member Functions inherited from QwtAbstractScaleDraw
void	invalidateCache ()
const QwtText &	tickLabel (const QFont &, double value) const

Additional Inherited Members
Public Types inherited from QwtAbstractScaleDraw
enum	ScaleComponent {   Backbone = 0x01,   Ticks = 0x02,   Labels = 0x04 }
typedef QFlags< ScaleComponent >	ScaleComponents

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Detailed Description

A class for drawing round scales.

QwtRoundScaleDraw can be used to draw round scales. The circle segment can be adjusted by QwtRoundScaleDraw::setAngleRange(). The geometry of the scale can be specified with QwtRoundScaleDraw::moveCenter() and QwtRoundScaleDraw::setRadius().

After a scale division has been specified as a QwtScaleDiv object using QwtAbstractScaleDraw::setScaleDiv(const QwtScaleDiv &s), the scale can be drawn with the QwtAbstractScaleDraw::draw() member.

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Constructor & Destructor Documentation

QwtRoundScaleDraw::QwtRoundScaleDraw

(

)

Constructor.

The range of the scale is initialized to [0, 100], The center is set to (50, 50) with a radius of 50. The angle range is set to [-135, 135].

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Member Function Documentation

void QwtRoundScaleDraw::drawBackbone ( QPainter *  painter ) const

protectedvirtual

Draws the baseline of the scale

Parameters:

painter

Painter

See also:

drawTick(), drawLabel()

Implements QwtAbstractScaleDraw.

void QwtRoundScaleDraw::drawLabel ( QPainter *  painter, double  value  ) const

protectedvirtual

Draws the label for a major scale tick

Parameters:

painter	Painter
value	Value

See also:

drawTick(), drawBackbone()

Implements QwtAbstractScaleDraw.

void QwtRoundScaleDraw::drawTick ( QPainter *  painter, double  value, double  len  ) const

protectedvirtual

Draw a tick

Parameters:

painter	Painter
value	Value of the tick
len	Lenght of the tick

See also:

drawBackbone(), drawLabel()

Implements QwtAbstractScaleDraw.

double QwtRoundScaleDraw::extent ( const QFont &  font ) const

virtual

Calculate the extent of the scale

The extent is the distance between the baseline to the outermost pixel of the scale draw. radius() + extent() is an upper limit for the radius of the bounding circle.

Parameters:

font	Font used for painting the labels

See also:

setMinimumExtent(), minimumExtent()

Warning:

The implemented algo is not too smart and calculates only an upper limit, that might be a few pixels too large

Implements QwtAbstractScaleDraw.

void QwtRoundScaleDraw::moveCenter

(

const QPointF &

center

)

Move the center of the scale draw, leaving the radius unchanged

Parameters:

center

New center

See also:

setRadius()

int QwtRoundScaleDraw::radius

(

)

const

Get the radius

Radius is the radius of the backbone without ticks and labels.

See also:

setRadius(), extent()

void QwtRoundScaleDraw::setAngleRange	(	double	angle1,
		double	angle2
	)

Adjust the baseline circle segment for round scales.

The baseline will be drawn from min(angle1,angle2) to max(angle1, angle2). The default setting is [ -135, 135 ]. An angle of 0 degrees corresponds to the 12 o'clock position, and positive angles count in a clockwise direction.

Parameters:

angle1
angle2	boundaries of the angle interval in degrees.

Warning:

• The angle range is limited to [-360, 360] degrees. Angles exceeding this range will be clipped.
• For angles more than 359 degrees above or below min(angle1, angle2), scale marks will not be drawn.
• If you need a counterclockwise scale, use QwtScaleDiv::setRange

void QwtRoundScaleDraw::setRadius

(

int

radius

)

Change of radius the scale

Radius is the radius of the backbone without ticks and labels.

Parameters:

radius

New Radius

See also:

moveCenter()