Hi,

I needed to inherit from qwt_plot_curve to add another CurveStyle (DottedLines) to the enum:

Qt Code: 
  1. /*          
  2.            - UserCurve
  3.            Styles >= UserCurve are reserved for derived
  4.            classes of QwtPlotCurve that overload drawCurve() with
  5.            additional application specific curve types.
  6. */
  7.     enum CurveStyle
  8.     {
  9.         NoCurve,
  10.  
  11.         Lines,
  12.         Sticks,
  13.         Steps,
  14.         Dots,
  15.  
  16.         UserCurve = 100
  17.     };
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I wanted to make a style called DottedLine, which connects every other point with a line. I need to derive a class and then redefine DrawCurve:

Qt Code: 
  1. void QwtPlotCurve::drawCurve(QPainter *painter, int style,
  2.     const QwtScaleMap &xMap, const QwtScaleMap &yMap, 
  3.     int from, int to) const
  4. {
  5.     switch (style)
  6.     {
  7.         case Lines:
  8.             if ( testCurveAttribute(Fitted) )
  9.             {
  10.                 // we always need the complete 
  11.                 // curve for fitting
  12.                 from = 0;
  13.                 to = dataSize() - 1;
  14.             }
  15.             drawLines(painter, xMap, yMap, from, to);
  16.             break;
  17.         case Sticks:
  18.             drawSticks(painter, xMap, yMap, from, to);
  19.             break;
  20.         case Steps:
  21.             drawSteps(painter, xMap, yMap, from, to);
  22.             break;
  23.         case Dots:
  24.             drawDots(painter, xMap, yMap, from, to);
  25.             break;
  26.         case DottedLines:
  27.             drawDottedLines(painter, xMap, yMap, from, to);
  28.             break;
  29.         case NoCurve:
  30.         default:
  31.             break;
  32.     }
  33. }
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(I added drawDottedLines at the bottom). How can I inherit the enum CurveStyles such that I can set the style using:

void QwtPlotCurve::setStyle(CurveStyle style)?

I can't inherit the enum right? Do I need to redefine setStyle to:

void MyPlotCurve::setStyle(MyCurveStyle style)? And if so, how do I define MyCurveStyle?

I hope this is not too confusing, thanks