@StudentScripter

This example shows how a use case could look like

https://doc.qt.io/qt-6/qtwidgets-graphicsview-basicgraphicslayouts-example.html

But as you can see, the custom items inherit from QGraphicsLayoutItem and QGraphicsItem.
So to properly use a QGraphicsItem in a layout, you have to inherit QGraphicsLayoutItem or use QGraphicsWidget directly... however I don't know how it fits in your existing logic/structure. It might break something... using layouts and "moving free / free resizable by user" is kinda counterproductive.

@Jammin44fm the paint method of QGraphicsItem is public so you can call it yourself with the painter you use in the delegate.

@jsulm
Indeed! Thank you for your reply.

@SGaist
Thanks for suggesting OpenGL, I think that might be a possibility at some point.
As of now, I got it to work by locking the UI updates and batch repainting all of the windows at once:

for(auto widget : qApp->topLevelWidgets()){ widget->setUpdatesEnabled(true); } qApp->processEvents(); for(auto widget : qApp->topLevelWidgets()){ widget->setUpdatesEnabled(false); }

I know this may not be the best way to achieve this, so I am all ears if there's any better way to limit UI updates to a single point in execution.
Thanks!

No, my idea was to build your set of resizable widgets with QSplitter and then add that QSplitter to your scene

Hi and welcome to devnet,

It will only follow it's parent widget if you put it in a layout that you set on the said parent widget. Otherwise it's up to you to handle the positioning and size of the child widget.

Keep Your drawing inside boundingRect() or in Your case exposed area. Probably in this case this will be the same for parent widget interaction i.e. mowing widget but will change when painting separate elements inside .

Anyway issue is with Your drawing of border.
alt text

QRectF border_rect = exposed_rect; border_rect.adjust( pen.widthF(), pen.widthF(), -pen.widthF(), -pen.widthF()); pPainter->drawRect(border_rect);

Zoom in image to see that each rectangle is inside boundingbox().