Transparent QLabel in QGraphicsView a good idea?

Question

I'm trying to write a piece of software that allows one to click on a video frame and mark the x,y coordinates of a location in the frame. To design this, I've been wanting to use a QGraphicsView subclass and, on the mouse click event, instantiate a QLabel with a PNG image "target" on where the click occurred.

So far I've gotten everything to work except getting the QLabel to be transparent. All of the info I've found online doesn't seem to work with the latest Qt. Should I totally rethink my design and utilize some sort of integration with painting in Qt? Or is there a way to salvage the QLabel PNG implementation and indeed make the label transparent?

Thanks, --Dany.

Answer 1

QLabel inside QGraphicsView is not a good idea indeed. QGraphicsView was designed to host QGraphicsItems, to display an image you should use QGraphicsPixmapItem.

Embedding QWidget into QGraphicsView has some overhead and was really designed for complex widgets that can't be easily reimplemented in terms of QGraphicItems.

Answer 2

I think a QGraphicsItem with ItemIgnoresTransformations flag is just what you want.