Hello.

I have a problem with my QwtPlot-derived class:
Qt Code: 
  1. class Plot2D : public QwtPlot
  2. {
  3. public:
  4.     Plot2D(QWidget *parent);
  5.     ~Plot2D();
  6.  
  7. private:
  8.     QwtPlotSpectrogram *meshGrid;
  9.     SpectrogramData *meshData; // public : QwtRasterData, 
  10.     ColorMap *meshMap; // : public QwtColorMap
  11.     // These two classes use their respective default destructors. No memory allocation takes place inside these classes.
  12.     QwtScaleDraw *scaleDraw;
  13.     QwtScaleWidget *rightAxis;
  14. };
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Its constructor and destructor are set to:
Qt Code: 
  1. Plot2D::Plot2D(QWidget *parent) :
  2.     QwtPlot(parent),
  3.     meshGrid(new QwtPlotSpectrogram()),
  4.     meshData(new SpectrogramData()),
  5.     meshMap(new ColorMap()),
  6.     scaleDraw(new QwtScaleDraw())
  7. {
  8.     meshGrid->attach(this);
  9.     meshGrid->setData(meshData);
  10.     meshGrid->setColorMap(meshMap);
  11.     rightAxis = axisWidget(QwtPlot::yRight);
  12.     rightAxis->setColorBarEnabled(true);
  13.     enableAxis(QwtPlot::yRight);
  14.     setAxisScaleDraw(QwtPlot::yLeft,scaleDraw);
  15. }
  16. Plot2D::~Plot2D()
  17. {
  18.     delete scaleDraw;
  19.     delete meshMap;
  20.     delete meshData;
  21.     delete meshGrid;
  22. }
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My program halts and eventually throws an error if I simply run it and subsequently close it (upon deleting the Plot2D object). This simple procedure is completed successfully if I comment out the bracketed instructions on either constructor or destructor. I'm guessing that there is something wrong with my implementation of memory management here. What might be the problem?