QGraphicsItem : keep position when zoom changes

[nilot]

Hello,

In the code below, I create a QGraphicsRectItem and I want to display its name with a QGraphicsSimpleTextItem. I want the size of the text to be unaffected by the zoom, so I use the flag QGraphicsItem::ItemIgnoresTransformations. I also want the position of the text to be centered on the QGraphicsRectItem.
Unfortunately you can see on the capture that when I unzoom ( on the right ), the text doesn't stay inside the rectangle Capture.jpg .
How to keep the text inside the rectangle and centered ?

#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsRectItem>
#include <QPen>
#include <QWheelEvent>
#include <cmath>
#include <QDebug>
 
class MainView : public QGraphicsView {
public:
  MainView(QGraphicsScene *scene) : QGraphicsView(scene) {  setBackgroundBrush(QBrush(QColor(255, 255, 255)));}
protected:
  void wheelEvent(QWheelEvent *event) {
    double scaleFactor = pow(2.0, event->delta() / 240.0);
    scale(scaleFactor, scaleFactor);
  }
};
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QGraphicsScene scene;
    scene.setSceneRect(0, 0, 800, 800);
    QGraphicsRectItem* rectItem = new QGraphicsRectItem(QRectF(0, 0, 400, 200));
    rectItem->setPos(200, 200);
    rectItem->setBrush(QColor(255, 0, 0));
    scene.addItem(rectItem);
 
    QGraphicsSimpleTextItem *nameItem = new QGraphicsSimpleTextItem("name", rectItem);
    QFont f = nameItem->font();
    f.setPointSize(12);
    nameItem->setFont(f);
    nameItem->setFlag(QGraphicsItem::ItemIgnoresTransformations);
    nameItem->setPos(rectItem->rect().center());
 
    MainView view(&scene);
    view.show();
 
    return a.exec();
}

#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsRectItem>
#include <QPen>
#include <QWheelEvent>
#include <cmath>
#include <QDebug>

class MainView : public QGraphicsView {
public:
  MainView(QGraphicsScene *scene) : QGraphicsView(scene) {  setBackgroundBrush(QBrush(QColor(255, 255, 255)));}
protected:
  void wheelEvent(QWheelEvent *event) {
    double scaleFactor = pow(2.0, event->delta() / 240.0);
    scale(scaleFactor, scaleFactor);
  }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QGraphicsScene scene;
    scene.setSceneRect(0, 0, 800, 800);
    QGraphicsRectItem* rectItem = new QGraphicsRectItem(QRectF(0, 0, 400, 200));
    rectItem->setPos(200, 200);
    rectItem->setBrush(QColor(255, 0, 0));
    scene.addItem(rectItem);

    QGraphicsSimpleTextItem *nameItem = new QGraphicsSimpleTextItem("name", rectItem);
    QFont f = nameItem->font();
    f.setPointSize(12);
    nameItem->setFont(f);
    nameItem->setFlag(QGraphicsItem::ItemIgnoresTransformations);
    nameItem->setPos(rectItem->rect().center());

    MainView view(&scene);
    view.show();

    return a.exec();
}

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Thank you