C++ (Qt)void QGraphicsView::setDragMode(DragMode mode)
C++ (Qt)void QGraphicsView::setDragMode(QGraphicsView::ScrollHandDrag);
C++ (Qt)void QGraphicsView::ensureVisible ( const QRectF & rect, int xmargin = 50, int ymargin = 50 )
void QGraphicsView::centerOn ( const QPointF & pos )
QGraphicsView::rect().center()
QGraphicsView::mapToScene
centerOn(mapToScene(rect().center());
QGraphicsScene::sceneRect
QGraphicsView::mapFromScene