Hi

I am having a bizarre problem with Q_OBJECT macro, if I include the maco in my class declaration the program does not run with the error

"You can't do that without a process to debug"

Qt Code: 
  1. #include <qwt_plot.h>
  2.  
  3. class QSpinBox;
  5. class QDialog;
  6. class Fitting;
  7.  
  8. ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  9. class FittingPlot  : public QwtPlot
  10. {
  11. 	Q_OBJECT  //the program runs if this is if commented out 
  12.  
  13. public:
  14. 	FittingPlot(QWidget *parent = NULL);
  15.  
  16. public slots:
  17. 	void upd();
  18.  
  19. private:
  20. 	QSpinBox* aSpinBox;
  21. 	QSpinBox* bSpinBox;
  22. 	QVBoxLayout* layout;
  23. 	QDialog* diag;
  24.  
  25. 	Fitting* tfit;
  26. 	int mtest;
  27. };
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This the implementation

Qt Code: 
  1. #include <qwt_plot.h>
  2. #include <QtGui>
  3.  
  4. #include "FittingPlot.h"
  5. #include "Fitting.h"
  6.  
  7. FittingPlot::FittingPlot(QWidget *parent)
  8. :QwtPlot(parent),mtest(0)
  9.  
  10. {
  11. 	aSpinBox = new QSpinBox;
  12. 	bSpinBox = new QSpinBox;
  13. 	layout = new QVBoxLayout();
  14. 	layout->addWidget(aSpinBox);
  15. 	layout->addWidget(bSpinBox);
  16. 	diag=new QDialog(this);
  17. 	diag->setLayout(layout);
  18. 	diag->show();
  19.  
  20. 	tfit=new Fitting();
  21.  
  22. 	QObject::connect(aSpinBox,SIGNAL(valueChanged(int)),tfit, SLOT(setTargetThreshold(int)) );
  23. 	QObject::connect(aSpinBox,SIGNAL(valueChanged(int)),tfit, SLOT(run()) );
  24. 	QObject::connect(aSpinBox,SIGNAL(valueChanged(int)),this, SLOT(upd()) );
  25. }
  26.  
  27. void
  28. FittingPlot::upd()
  29. {
  30. 	mtest++;
  31. }
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When the code does run (with Q_OBJECT commnented out, the slot upd does not get called with warnin message

"warning: Object::connect: No such slot QwtPlot::upd()

The other two slots work in the Fitting Class work OK

Does anyone have any ideas why this is happening?