Graphic by Qwt in a QGraphicsView

[ChoCChoK]

Hi all !

I've got a big problem when coding a program. I wanna show a graphic in a QGraphicsView with Qwt which will show me some marks, but I can't. There's no bug, but nothing is showed :

vector<int> x, y;
QwtPlotCurve crv;
QwtPlot *myPlot = new QwtPlot(QwtText("Graphique de notes"), this);
QRect r = graphiqueNotes->rect(); // "graphiquesNotes" is a QGraphicsView on the window
QPainter painter(this);
 
painter.setClipRect(r);
 
x.push_back(1); // Let's suppose that we have two marks : one 8 and one 15
x.push_back(2);
y.push_back(8);
y.push_back(15);
 
xMap.setScaleInterval(0, (double)x.size() + 1);
yMap.setScaleInterval(0, 20);
 
xMap.setPaintInterval(r.left(), r.right());
yMap.setPaintInterval(r.top(), r.bottom());
 
QwtSymbol sym;
 
sym.setStyle(QwtSymbol::Cross);
sym.setPen(QColor(Qt::black));
sym.setSize(5);
crv.setSymbol(sym);
crv.setPen(QColor(Qt::darkGreen));
crv.setStyle(QwtPlotCurve::Lines);
crv.setRenderHint(QwtPlotItem::RenderAntialiased);
 
crv.setRawData(x.data(), y.data(), x.size());
crv.attach(myPlot);
 
myPlot->replot();
 
crv.draw(&painter, xMap, yMap, r);

vector<int> x, y;
QwtPlotCurve crv;
QwtPlot *myPlot = new QwtPlot(QwtText("Graphique de notes"), this);
QRect r = graphiqueNotes->rect(); // "graphiquesNotes" is a QGraphicsView on the window
QPainter painter(this);

painter.setClipRect(r);

x.push_back(1); // Let's suppose that we have two marks : one 8 and one 15
x.push_back(2);
y.push_back(8);
y.push_back(15);

xMap.setScaleInterval(0, (double)x.size() + 1);
yMap.setScaleInterval(0, 20);

xMap.setPaintInterval(r.left(), r.right());
yMap.setPaintInterval(r.top(), r.bottom());

QwtSymbol sym;

sym.setStyle(QwtSymbol::Cross);
sym.setPen(QColor(Qt::black));
sym.setSize(5);
crv.setSymbol(sym);
crv.setPen(QColor(Qt::darkGreen));
crv.setStyle(QwtPlotCurve::Lines);
crv.setRenderHint(QwtPlotItem::RenderAntialiased);

crv.setRawData(x.data(), y.data(), x.size());
crv.attach(myPlot);

myPlot->replot();

crv.draw(&painter, xMap, yMap, r);

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What do you think about this ? Can you compile and tell me if you see something ?

Thank you very much.
ChoCChoK.

[Uwe]

Implement a QGraphicsItem and paint inside of YourGraphicsItem:aint().

Uwe

[ChoCChoK]

Thank you very much for your help, Uwe, but I don't understand what QGraphicsItem to implement. It's a virtual class.

[Uwe]

Then better start with reading some books about Qt anf OO programming and ask in the newbie section of this forum - this is the right place, for very basic questions.

Uwe