QGraphicsView no refreshement

[evergreen]

Hi,
I’m currently working with a QGraphicsView and I encounter some problems either when I try to put a transparent object over it or try to apply a blur effect.
I ‘m pretty sure that the reason is the same : the QGraphicsView always refreshes its display which messes with the transparency and the blur effect probably instantly desappear.

So, I would like to know if there’s a way to temporary stop a QGraphicsView (or the QGraphicsScene in it) to refresh. To somehow freeze its display.

Thanks

[MarekR22]

You have done something wrong! Show your code!

[evergreen]

Well I got about 50 files so it's gonna be complicated, but If you just create a QGraphicsView and apply a blur effect on it, it does not work.

QGraphicsView* graph = new QGraphicsView;
QGraphicsBlurEffect *effect = new QGraphicsBlurEffect() ;
graph->setGraphicsEffect(effect);

QGraphicsView* graph = new QGraphicsView;
QGraphicsBlurEffect *effect = new QGraphicsBlurEffect() ;
graph->setGraphicsEffect(effect);

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Note that it perfectly works on classical widgets. Taht's why I think QGraphicsView is the problem and it's because of it's refeshments.

[wysota]

So you are stacking two views one over another? Isn't it easier to just add the items from this additional view to the original scene?

[evergreen]

Nope because in my application a view could be over two others thats why it's got to be over.

[wysota]

The problem is that's not how widgets work and if you want composition, it will be hard to obtain such an effect. Why do you need a view to be over two others? Why don't make them all a single view/scene?

[evergreen]

I want the user to be able to work on several subwindows, that way I use a QMdiArea and a QGraphicsView in each of them.
Then I want that when the user ask to pop up an option window over this QmidArea and blur all the rest of the application.

Maybe I'm just too ambitious...!

[wysota]

I fail to see how this requires stacking graphics views onto each other.

As for bluring the background -- you should just make your dialog modal and leave handling the visual effects to the desktop system. I personally don't like when some application tries to convince me it knows better what's good for me. If I want blocked windows blurred, I'll set it up in my window manager.