Hands-On High Performance Programming with Qt 5

QQuickPaintedItem

This is a convenience class using the QPainter interface internally. It can be used much in the style of a standard widget class, as can be seen in the following example:

class PaintedItemTriangle : public QQuickPaintedItem{public:  void paint(QPainter* painter)  {    const QPolygonF polygon({ ... });     QBrush brush(Qt::yellow);    painter->setBrush(brush);    painter->drawPolygon(polygon);  }};

This is very familiar and convenient, but it results in somehow not-so-amazing performance, as we will discuss in detail later in this chapter.