View Full Version : QGraphicsItem::scenePos() not returning scene coordinates of item

19th September 2006, 20:04
OK, this only relates to Qt 4.2.

Take this sample code:
QGraphicsScene* scene = new QGraphicsScene(this);

scene->addEllipse(QRectF(110, 110, 20, 20)); // a circle with centre 120,120 and diameter 20

QGraphicsItem* item = sceneScene->itemAt(120, 120);
cout << item->scenePos().x() << ", " << item->scenePos().y() << endl;Now I would expect this to return the scene position of the object it found at, i.e. "120, 120" since QGraphicsItem::scenePos() just returns QGraphicsItem::mapToScene(0,0).

However it only ever returns "0, 0".

In fact
cout << item->mapToScene(item->pos()).x() << ", " << item->mapToScene(item->pos()).x() << endl;
cout << item->pos().x() << ", " << item->pos().y() << endl;also all return "0, 0" whereas you would expect at least one of them to return something else.

Is this a feature or a bug? Does anyone else have this problem or know why I am getting this result?

26th September 2006, 06:38
With which exact version of Qt 4.2 did you notice this? I tested with 4.2.0-rc1 and I noticed the same behaviour. I couldn't find anything related in the Task Tracker (http://www.trolltech.com/developer/task-tracker) nor TT's mailing lists (http://lists.trolltech.com/), though. Maybe try a recent snapshot of Qt 4.2 and inform the trolls if the problem still persists..?