Rotate items in qwt

[jesse_mark]

What type of coordinates are these: plot or widget coordinates ?

im using plot coordinates and im usgin qwtcurve and give setdata and this is a snipt of the code ... it draw the rectangle

QwtPlotCurve *curve1 = new QwtPlotCurve("Curve 1");
QwtPointSeriesData* myData = new QwtPointSeriesData;
QVector<QPointF>* samples = new QVector<QPointF>;
samples->push_back(QPointF(1000,1000)); // my origin
samples->push_back(newPosition(100,100,8200,1000,-30));
samples->push_back(newPosition(100,100,8200,8200,-30));
samples->push_back(newPosition(100,100,1000,8200,-30));
samples->push_back(QPointF(1000,1000));
myData->setSamples(*samples);
curve1->setData(myData);

curve1->setBrush(mybrush);

curve1->setPen(p);

curve1->attach(ui->qwtPlot);

Use QTransform.

do you mind tell me how can i use QTransform with qwtcurve ??

thank you so much