painting problem

I have a signal plot with a grid where I would like to change the background color of just some of the grid cells.
Tried this:

Code:

---

void SignalView::paintEvent(QPaintEvent*)
{
    QPainter* painter = new QPainter(this);
 
    QColor bpColor;
    bpColor.setNamedColor("grey");
 
    painter->setPen(bpColor);
    QwtPainter::drawRect(painter, 500, 500, 100, 500);
}

---

But no paint and the message QPaintDevice: Cannot destroy paint device that is being painted appears in the application output window.

Any suggestions are welcome.

Your approach won't work - all painting needs to be done in a QwtPlotItem.

Uwe