There is no scrollbar. If you want one, you have to make one on your own, but it wouldn't make any sense.
You have your data and you have your series. Now you can decide which parts you want to show in your chart (this is the "scrolling")
@tague Are you currently updating every time a point is added? If so, I wondered if you could buffer the incoming data so that you do not update so frequently? Perhaps use a QTimer to control update frequency.
@fcarney I put the QAbstractItemModelTester in both my model, and my proxy model, and... no errors. I also swapped it to FailureReportingMode::Fatal to double check, and nothing. The endless calls to data from VXYModelMapper continue.
Actually I saw few java script programs for pointing accurate pixel values on image by using Mercator projection and it's formula.
I checked it works fine in Java script. But in qt I want to display whole lat long trace so wanted to plot chart with image as it's background. But not able to correctly det the background image as per chart x and y axis values.