Inheriting from QwtPlotCurve problems

[dbrmik]

Hi

I have a my Curve class derived from QwtPlotCurve as shown

class Curve :public QwtPlotCurve  {
	Q_OBJECT;
public:
	Curve(QWidget* parent, QString s,QColor colour,int size);
	virtual ~Curve();
	QCheckBox* checkBox;
	float* plotData;
	int size;
signals:
	void doPlotUpdate();
};
 
Curve::Curve(QWidget* parent,QString s,QColor color,int size):
 QwtPlotCurve(s),
 checkBox(new QCheckBox(s)),
 plotData(new float[size]),
 size(size)
{
	setPen(QPen(color));
	QObject::connect(this->checkBox,SIGNAL(stateChanged(int)),parent, SLOT(updatePlots()));
}

class Curve :public QwtPlotCurve  {
	Q_OBJECT;
public:
	Curve(QWidget* parent, QString s,QColor colour,int size);
	virtual ~Curve();
	QCheckBox* checkBox;
	float* plotData;
	int size;
signals:
	void doPlotUpdate();
};

Curve::Curve(QWidget* parent,QString s,QColor color,int size):
 QwtPlotCurve(s),
 checkBox(new QCheckBox(s)),
 plotData(new float[size]),
 size(size)
{
	setPen(QPen(color));
	QObject::connect(this->checkBox,SIGNAL(stateChanged(int)),parent, SLOT(updatePlots()));
}

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My intention is to connect the signal from the checkbox to the slot updatePlots so that when the checkbox is enabled the plot is displayed. I am getting the following linking error

debug\moc_QwtSeahawkPlot.cpp:42: error: `staticMetaObject' is not a member of `QwtPlotCurve'
debug\moc_QwtSeahawkPlot.cpp: In member function `virtual void* Curve::qt_metacast(const char*)':
debug\moc_QwtSeahawkPlot.cpp:56: error: `qt_metacast' is not a member of `QwtPlotCurve'
debug\moc_QwtSeahawkPlot.cpp: In member function `virtual int Curve::qt_metacall(QMetaObject::Call, int, void**)':
debug\moc_QwtSeahawkPlot.cpp:61: error: `qt_metacall' is not a member of `QwtPlotCurve'
debug\moc_QwtSeahawkPlot.cpp: In member function `void Curve::doPlotUpdate()':

Also when I call attach I get the following compilation error.

mycurve=new Curve(this,"Input Data","yellow",1024);
mycurve->attach(plot);

mycurve=new Curve(this,"Input Data","yellow",1024);
mycurve->attach(plot);

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c:/Qt/4.5.0/include/qwt./qwt_plot_item.h: In member function `void QwtSeahawkPlot::updatePlots()':
c:/Qt/4.5.0/include/qwt./qwt_plot_item.h:117: error: `void QwtPlotItem::attach(QwtPlot*)' is inaccessible
SeaHawkDebug\QwtSeahawkPlot.cpp:127: error: within this context
SeaHawkDebug\QwtSeahawkPlot.cpp:127: error: `QwtPlotItem' is not an accessible base of `Curve'
mingw32-make[1]: *** [debug/QwtSeahawkPlot.o] Error 1

Could someone help me out

Regards