The following partially works and I post in the hopes that someone might get an idea that will fix my issue :)

bool ZoomCode::event(QEvent *event) { if (event->type() == QEvent::NativeGesture) { return gestureEvent(static_cast<QNativeGestureEvent*>(event)); } return QWidget::event(event); } bool ZoomCode::gestureEvent(QNativeGestureEvent *e) { float value = e->value(); textEdit->setFontPointSize(NULL); // zoom does not work without this textEdit->selectAll(); // some part of the text has to be selected before the zoom in the text starts to work. It does NOT matter if it is the WHOLE text or just a character in the text, just as long as something gets highlighted. Afterwards, nothing has to be highlighted again for the zoom to work. The zoom works on the whole text, no matter what part has been highlighted. if(value >0) { zoomIn(value + 5); // + 5 to add some zoom strength } else if(value < 0) zoomOut(value - 5); // -5 to add some zoom strength } }

@mrjj I tried your code, here's the result:

@stcorp I'll have to look at that later, but I didn't know about the resizeContent method from Flickable. From waht I'm seeing in your code and in the documentation, this looks like a good solution. Thanks!

Hi @f.serreau
I have tested your example, and it works correctly with no errors.
I tested it on Windows 10 (Fall Update), MS VS2017 and Qt 5.11.0.

Thanks for sharing your findings !

:D
I haven't had much time to test if the bug exists in Qt5. I'll check it out and update the topic accordingly. If the bug is still there, of course, I will submit the fix.

Thanks for your time.

I think I found a solution. I roughly quadrupled the QCameraViewfinder size and repositioned it to the middle.
Its all done with "cameraVf->setGeometry(x,y,x,y);". And I parented the viewfinder to a new QFrame
to have a frame and to have the viewfinder not overlaying the start button.

mainwindow.cpp

... QFrame *frameVideo = new QFrame(frame4); // extra frame where the video is in frameVideo->setGeometry(5,35,375,380); camera = new QCamera("/dev/video0"); cameraVf = new QCameraViewfinder(frameVideo); camera->setViewfinder(cameraVf); cameraVf->setGeometry(0,0,375,380); QCameraViewfinderSettings vfsettings; vfsettings.setPixelFormat(QVideoFrame::Format_YUV420P); vfsettings.setResolution(640,480); camera->setViewfinderSettings(vfsettings); cameraVf->show(); ... void MainWindow::onZoomClicked(){ if(cameraVf->width() != 1600) { cameraVf->setGeometry(-590,-490,1600,1440); // zoom in } else { cameraVf->setGeometry(0,0,375,380); // zoom out } }

@Joel-Bodenmann
@raven-worx

They're all good answers :)
Thank you very much :)

Hi and welcome
Many ways to do this, but here is my suggestion.

Add a signal to your graphicview class

signals: void MWheelActivated(bool ZoomIn);

and hook it up to a slot in your mainwindow with the connect function.
http://doc.qt.io/qt-5.5/signalsandslots.html

then in GraphicsView::wheelEvent(QWheelEvent *e)
you
emit MWheelActivated ( (e->delta() > 0));
and No zooming here!

Then in mainwindow slot

mainwindow:: MWheelActivated ( bool ZoomIn ) { if ( ZoomIn ) { view1->zoomIn ( 6 ); view2->zoomIn ( 6 ); } else { view1->zoomOut ( 6 ); view2->zoomOut ( 6 ); } }

Hope it helps.

@vishnu RightClick > View Page Source ;)

The documentation of Qt3D is getting improved to match Qt's standard. The module with Qt 5.5 is a tech preview

@HappyCoder

Out of personal experience I recommend also to ask your question on QWT mailing list
AFAIK QWT is still independent and only based on Qt libs. Uwe has been monitoring this forum in the past, but answers are potentially faster through QWT mailing list.

So, finally I used a QGraphicsView and a QGraphicsScene in which I add my QWidget and now I can use the scroll (with the dragMode). I didn't implemented the zoom yet, but it I'm working on.

Thanks a lot for your help