Subclass of QGraphicsLayoutItem for stretchers?

The specializations of QGraphicsLayout (e.g. QGraphicsLinearLayout) include an开发者_如何学编程 insertStretch method.

What kind of object do QGraphicsLinearLayout::insertStretch method insert in the list of items managed by the layout? Better asked: what type of object is returned by QGraphicsLayout::itemAt method when called for a stretch position?

I've never investigated this, so I don't know, but if you are truly curious, you could ask for an object at that position. Assuming it doesn't return NULL, you could then work your way through the meta information and find out quite a bit of information about it.

I wouldn't be too surprised, however, if it were a stock QWidget (empty, drawing nothing).