Add curve styles(Lines, Dots) to oscilloscope

[Yunusbcr]

According to documentation QwtPlotCurve::Dots, "FASTER"

So, QwtPlotCurve::Dots added as a curve style option to produce scatter plot in oscilloscope

[fusge]

Thanks for submitting this. A quick visual test shows that changing the line style does not take effect in the oscilloscope. Can you add logic to this so that users are able to use the other styles if they wish? A good place to start is in the scope.hpp/scope.cpp file where we implement pen style allowed types, as well as oscilloscope.cpp where we hook these style changes to qt events. Perhaps reusing those and replacing Qt::PenStyle with qwtcurvestyle?

[Yunusbcr]

This behavior is expected and desired. Line style is effective if only curve style chosen as "lines". If curve style is "dots", there will be no line to have style, basically all data points are just dots(scatter plot). I can grey out the line style drop-down menu when dots is chosen, if that is what you want?