NAME

       QwtRoundScaleDraw - A class for drawing round scales.

SYNOPSIS

       #include <qwt_round_scale_draw.h>

       Inherits QwtAbstractScaleDraw.

       Inherited by QwtAnalogClockScaleDraw, and QwtCompassScaleDraw.

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

   Additional Inherited Members

Detailed Description

       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 & 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].

Member Function Documentation

   void QwtRoundScaleDraw::drawBackbone (QPainter * painter) const [protected],  [virtual]
       Draws the baseline of the scale

       Parameters:
           painter Painter

       See also:
           drawTick(), drawLabel()

       Implements QwtAbstractScaleDraw.

   void QwtRoundScaleDraw::drawLabel (QPainter * painter, double value) const [protected],
       [virtual]
       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
       [protected],  [virtual]
       Draw a tick

       Parameters:
           painter Painter
           value Value of the tick
           len Length 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

       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.

   void QwtRoundScaleDraw::moveCenter (const QPointF & center)
       Move the center of the scale draw, leaving the radius unchanged

       Parameters:
           center New center

       See also:
           setRadius()

   double QwtRoundScaleDraw::radius () const
       Get the radius

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

       Returns:
           Radius of the scale

       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 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()
   void QwtRoundScaleDraw::setRadius (double radius)
       Change of radius the scale
       Radius is the radius of the backbone without ticks and labels.
       Parameters:
           radius New Radius
       See also:
           moveCenter()

Author

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