Painting a dynamically created QQuickPaintedItem subclass

[_Michel]

Hi everyone. I'd like to know why I can't paint a dynamically created QQuickPaintedItem subclass. Here is an example :

@
// the class I need to draw
class Circle : public QQuickPaintedItem
{
Q_OBJECT
// ... some convenient properties along with their setters and getters
public:
Circle(QQuickItem *parent = 0) : QQuickPaintedItem(parent) { }
void Circle::paint(QPainter *painter) {
//... set a QPen and draw
painter->drawEllipse(boudingRect(). adjusted(1, 1, -1, -1));
}
}
@

@
// The circle class is registered in main.cpp
qmlRegisterType<Circle>("Stuff", 1, 0, "Circle");
@

-> I can see the circle if I use the Circle in a qml file.
@
Circle {
// this circle is drawn
}
@

// Now, imagine that I need a container, we'll call it "Chart". This
container is also registered.
@
class Chart : public QQuickItem {
Q_OBJECT
// ... some convenient properties along with their setters and getters

public:
Chart(QQuickItem *parent = 0) : QQuickItem(parent) {
m_circle = new Circle(this); // should be the same as setParentItem(this)
m_circle->setContentsSize(QSize(width(), height())); // it needs a size
m_circle->setParent(this); // different from parent item
// setFlag(ItemHasContent, true|flase) has no effect
}
Circle *m_circle;
}
@

You can see that the Circle is dynamically allocated. It is not drawn, I
don't know why. The Circle::paint method is not called. It is as if the
scene does not know about it.
At first, I thought it was because of the chart being only a QQuickItem and not a painted item. (This is why I played with the ItemHasContent flag )
so, I've put another circle inside the chart in QML :

@
Chart {
...
Circle {
// this circle is drawn but there should be also another circle (the one created in C++)
}
}
@

[_Michel]

Today , when reading "this blog":http://www.kdab.com/analysing-qtquick-apps-gammaray-button-gone/?utm_source=rss&utm_medium=rss&utm_campaign=analysing-qtquick-apps-gammaray-button-gone post from yesterday, I stumbled on

bq. Might it be size ‘zero’ or misplaced?

I tried to give a size to the circle, and that's it, it's drawn.