Hello,

I had posted a feature request on the QWT project page (http://sourceforge.net/p/qwt/feature-requests/69/). I think I did not make myself totally clear. Therefore I want to continue the discussion here:


What I want to do is to use a different plot layout for a QwtPlotSpectrogram. I want to force the plot canvas to be quadratic. I tried to subclass QwtPlotLayout and make one change in the method activate().

From my understanding the class QwtPlotLayout is designed to be subclassed and the method activate() is designed to be overloaded.

In the method activate() the layout is set by accessing d_data (e.g. d_data->canvasRect.setRect() ). I do not see how to do anything in an overloaded method activate() without access to d_data.

If you have any ideas how to modify the method activate() in a class derived from QwtPlotLayout, please let me know.

Best,
Sebastian