Qwt User's Guide
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A class for drawing round scales. More...
#include <qwt_round_scale_draw.h>
Public Member Functions | |
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 |
Protected Member Functions | |
virtual void | drawTick (QPainter *, double val, 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].
void QwtRoundScaleDraw::drawBackbone | ( | QPainter * | painter | ) | const [protected, virtual] |
Draws the baseline of the scale
painter | Painter |
Implements QwtAbstractScaleDraw.
void QwtRoundScaleDraw::drawLabel | ( | QPainter * | painter, |
double | value | ||
) | const [protected, virtual] |
Draws the label for a major scale tick
painter | Painter |
value | Value |
Implements QwtAbstractScaleDraw.
void QwtRoundScaleDraw::drawTick | ( | QPainter * | painter, |
double | value, | ||
double | len | ||
) | const [protected, virtual] |
Draw a tick
painter | Painter |
value | Value of the tick |
len | Lenght of the tick |
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.
font | Font used for painting the labels |
Implements QwtAbstractScaleDraw.
void QwtRoundScaleDraw::moveCenter | ( | const QPointF & | center | ) |
Move the center of the scale draw, leaving the radius unchanged
center | New center |
double QwtRoundScaleDraw::radius | ( | ) | const |
Get the radius
Radius is the radius of the backbone without ticks and labels.
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.
angle1 | |
angle2 | boundaries of the angle interval in degrees. |
void QwtRoundScaleDraw::setRadius | ( | double | radius | ) |
Change of radius the scale
Radius is the radius of the backbone without ticks and labels.
radius | New Radius |