My first program with QGraphicsView

[Morea]

I think I store all my questions about QGraphicsView in this thread.

First problem, I have a class Planet that is subclassedfrom GraphicsItem and I have this to draw it

void Planet::paint(QPainter* painter, QStyleOptionGraphicsItem* option,QWidget* widget)
{
	painter->setBrush(QColor(Qt::red));
	painter->drawEllipse(x,y,2*radius,2*radius);
}

void Planet::paint(QPainter* painter, QStyleOptionGraphicsItem* option,QWidget* widget)
{
	painter->setBrush(QColor(Qt::red));
	painter->drawEllipse(x,y,2*radius,2*radius);
}

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but all I get is a black circle on a white background. And the view isn't updated very much. How do I draw the ellipse and how do I update it more often?