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

QwtRoundScaleDraw - A class for drawing round scales.

#include <qwt_round_scale_draw.h>

Inherits QwtAbstractScaleDraw.

Inherited by QwtAnalogClockScaleDraw, and QwtCompassScaleDraw.


QwtRoundScaleDraw ()
Constructor. virtual ~QwtRoundScaleDraw ()
Destructor. void setRadius (double radius)
double radius () const
void moveCenter (double x, double y)
Move the center of the scale draw, leaving the radius unchanged. void moveCenter (const QPointF &)
QPointF center () const
Get the center of the scale. void setAngleRange (double angle1, double angle2)
Adjust the baseline circle segment for round scales. virtual double extent (const QFont &) const


virtual void drawTick (QPainter *, double value, double len) const
virtual void drawBackbone (QPainter *) const
virtual void drawLabel (QPainter *, double val) const

A class for drawing round scales.

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

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].

Draws the baseline of the scale

Parameters:

painter Painter

See also:

drawTick(), drawLabel()

Implements QwtAbstractScaleDraw.

Draws the label for a major scale tick

Parameters:

painter Painter
value Value

See also:

drawTick(), drawBackbone()

Implements QwtAbstractScaleDraw.

Draw a tick

Parameters:

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

See also:

drawBackbone(), drawLabel()

Implements QwtAbstractScaleDraw.

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

Returns:

Calculated extent

See also:

setMinimumExtent(), minimumExtent()

Warning:

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

Implements QwtAbstractScaleDraw.

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

Parameters:

center New center

See also:

setRadius()

Get the radius

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

Returns:

Radius of the scale

See also:

setRadius(), extent()

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 or equal than 360 degrees above or below min(angle1, angle2), scale marks will not be drawn.
  • If you need a counterclockwise scale, use QwtScaleDiv::setInterval()

Change of radius the scale

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

Parameters:

radius New Radius

See also:

moveCenter()

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Wed Jan 2 2019 Version 6.1.4