QScreen, QGraphicsScene, QGraphicsView size

Norduk

Hi there! Maybe somebody could help me, I have 2 questions:

I'm trying to check the resolution of my device to prevent going outside the scene. I do it like this:

QScreen *screen = QApplication::primaryScreen();
QRect screenGeometry = screen->geometry();
this->screenWidth = screenGeometry.width();
this->screenHeight = screenGeometry.height();

As a result I receive values 360 and 720, but my device has actually 720x1440 (twice larger).

So, the first question is, why Qt by default use this resolution instead of original and how I can change it?

Does anybody has any links to examples where QGraphicsScene/QGraphicsView classes are used to create a scalable application?