@Joe-von-Habsburg Yes you can draw lines on a QGraphicsScene, I never suggested you not use a QChart (or equivalent, QChart is not considered wonderful and it is being replaced by QtGraphs, for all I know that may be better here) for drawing charts, there is a reason that is its own component. Since I don't know anything about QCharts and zooming I would not know about axes and what the consequences might be. I only know what I wrote and the links I referred you to, which may have alternative approaches.

@jeanmilost Your logic seems to be correct. What you have to do is to move the re-calculation of Scrollbar size & position to the Rectangle rcPageContainer because you are applying scale for that. Rectangle { id: rcPageContainer objectName: "rcPageContainer" ... /// called when page viewport width changed onWidthChanged: { sbHorz.size = rcPageViewport.width / rcPageContainer.width sbHorz.position = Math.min(Math.max(sbHorz.position, 0.0), 1.0 - (sbHorz.size)); } /// called when page viewport height changed onHeightChanged: { sbVert.size = rcPageViewport.height / rcPageContainer.height sbVert.position = Math.min(Math.max(sbVert.position, 0.0), 1.0 - (sbVert.size)); } }

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: [image: 0a2df4f3-38c9-4f54-affe-c60ba74d14c0.png]

QZoomableImage

Hello, I encountered the same problem as you, did you solve it, it will be black or blue screen when zoomed in

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. [image: CTtLfvul.png] 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