QGraphicsView overlay on top of QOpenGLWidget?

jdlyga

I have an idea that sounds possible on paper but I've been having trouble implementing.

I have a QOpenGLWidget that is used to view a large high resolution image. (It's using OpenGL for efficiency since there's a lot of cuts made to the image using clipping, etc). I'm trying to overlay a QGraphicsView+QGraphicsScene on top of the QOpenGLWidget to draw shapes and lines on top of the image, and interact with those shapes and lines.

I've been having a couple problems with this. First, I can't figure out a way to overlay the QGraphicsView on top of the QOpenGLWidget. I've tried a number of suggestions, including setting the two widgets to the same cell in a grid layout.

QGridLayout * layout = new QGridLayout;
layout->setContentsMargins(0, 0, 0, 0);
layout->addWidget(m_GraphicsView);
layout->addWidget(m_ImageGL);
m_Owner->setLayout(layout);

However, this isn't working. I'm only seeing one of the widgets. I figure this might be a transparency issue, so I tried setting some transparency flags.

m_GraphicsView->viewport()->setAttribute(Qt::WA_TranslucentBackground);
m_GraphicsView->viewport()->setAttribute(Qt::WA_NoSystemBackground);
m_GraphicsView->viewport()->setAttribute(Qt::WA_NoBackground);
m_GraphicsView->viewport()->setWindowFlags(Qt::FramelessWindowHint);
m_GraphicsView->viewport()->setAttribute(Qt::WA_NoSystemBackground);
m_GraphicsView->viewport()->setStyleSheet("background: transparent");

m_GraphicsView->setAttribute(Qt::WA_TranslucentBackground);
m_GraphicsView->setAttribute(Qt::WA_NoSystemBackground);
m_GraphicsView->setAttribute(Qt::WA_NoBackground);
m_GraphicsView->setWindowFlags(Qt::FramelessWindowHint);
m_GraphicsView->setAttribute(Qt::WA_NoSystemBackground);
m_GraphicsView->setStyleSheet("background: transparent");


m_ImageGL->viewport()->setAttribute(Qt::WA_TranslucentBackground);
m_ImageGL->viewport()->setAttribute(Qt::WA_NoSystemBackground);
m_ImageGL->viewport()->setAttribute(Qt::WA_NoBackground);
m_ImageGL->viewport()->setWindowFlags(Qt::FramelessWindowHint);
m_ImageGL->viewport()->setAttribute(Qt::WA_NoSystemBackground);
m_ImageGL->viewport()->setStyleSheet("background: transparent");

m_ImageGL->setAttribute(Qt::WA_TranslucentBackground);
m_ImageGL->setAttribute(Qt::WA_NoSystemBackground);
m_ImageGL->setAttribute(Qt::WA_NoBackground);
m_ImageGL->setWindowFlags(Qt::FramelessWindowHint);
m_ImageGL->setAttribute(Qt::WA_NoSystemBackground);
m_ImageGL->setStyleSheet("background: transparent");

I might have gone a little overboard here, but I'm setting every flag that I've seen suggested and I'm still not seeing what I'm expecting. Does anyone have any ideas?

SGaist

Hi and welcome to devnet,

Did you try with QStackedLayout with StackingMode set to StackAll ?

Hope it helps