Quote Originally Posted by veiovis View Post
But with multiple Qgraphicsviews the management of the substates would be way easier. For example scaling the graphicsview to view all substates of a states at once is one command.
With one big graphicsscene I would need to do that by hand.
It is always one command, the difference is what the subject of that command is.

QGraphicsItem::childrenBoundingRect() returns a rectangle that encompasses all its children. You can use that to calculate the scale you need to apply to an item that contains the substate items to make all its children cover a particular area.