Qt Printing problem

Question

I have a QGraphics scene its Rect is 0,0,2000,800

I want to get print out in A4 all this scene. How can I do it?

( I try it but it is unreadable. I want to get print out readably )

I use this codes

ui.graphicsView->setRect(0,0,2700,800); 
QPainter painter(&printer);
ui.graphicsView->render (&painter,scene->sceneRect());

I cant show all scene on A4 paper. On screen I use scroll bar but when I try to print out I cant show all scene.