qtcharts | Qt Charts module provides a set of easy to use chart

Upgrade your compiler to the latest VS2019 version (16.11) - see also https://bugreports.qt.io/browse/QTBUG-97999

extern a class member is not allowed, If we can do that, for instances of a class type, compiler don't know which address to resolve while linking. you can do like this:

So I finally found the solution myself. From what I understand, the reason you cannot find QtWebEngine in the Raspberry Pi OS repositories, is that the Pi OS is made to run on all Raspberry Pi's, including Pi 1 and Pi 2, which have an ARMv6 and ARMv7 CPU architecture respectively. The WebEngine module however is platform dependend and not tested, compiled and distributed for ARMv6/7 anymore, so they won't release it in the repositories for Raspberry Pi OS. Luckily though, the Raspberry Pi 3 that I use has ARMv8, so it is possible to install QtWebEngine from Debian repositories, which offer QtWebEngine for exactly that architecture. Here is how:

Open your sources.list file

Why RPATH_CHECK in CMake deletes executable?

Because that's what it does. (?)

Is it correct behavior of CMake, or it is a bug?

Correct.

What RPATH_CHECK should do?

Check if the file has desired RPATH, and if it doesn't, the file should be removed.

If you have any other concerns about RPATH features in CMake, I posted the source code in the last answer - all is there. Search for RPATH_CHECK in CMake source tree, and you'll find the find the function - from function names you can "guess" meaning and the algorithm used.

I made the 2 changes:

1. paint the background in a slot function.
2. emit the slotAreaChanged signal.

Here is the code

As you write in your ChartView class constructor, ChartView needs to get QChart as its parent. when you are trying to promote it you didn't set QChart as the parent of ChartView. so it didn't display.

and the second mistake is that you choose QWidget and you are trying to promote the chart view to it, choose one GraphicsView Item instead of QWidget.

But you shouldn't add your chart by promoting.

The problem is caused because the QChartView has the expansion sizePolicy as opposed to the QOpenGLWidget, so when it becomes visible it expands, hiding the other widget. The solution is to set a stretch factor associated with each widget in the layout:

Doing ui->graphicsView = new QChartView(chart); does not replace the QChartView, you are just assigning the pointer. The solution is to reuse the existing QChartView so it changes to: ui->graphicsView->setChart(chart);.

ADTF does not deploy QtCharts binaries because the license is incompatible. Qt is basically LGPL licenesed which works fine with ADTF license. But some components are licensed under GPL, QtCharts is one of it. You are not allowed to use QtCharts with ADTF because then you violate the combined work rule described within GPL. GPL is not working with commercial and closed source licenses, only with open source GPL compatible licenses like GPL itself, MPL or others. Anyway, because the binary is missing you are getting the error, that some dependencies are missing. But even when you put the binary there, it is not allowed, neither private nor commercial. Its incompatible and thats why ADTF tries to protect the customer and delivers only LGPL content. You even not allowed to use commercial Qt with ADTF using open source Qt because Qt declines mixing oss with commercial license even thats the same binary (politics...). Only chance, buy qtcharts standalone from qt marketplace then its compatible with LGPL. But you have to put the binary yourself. Or you link static, which is allowed with commercial/marketplace license from Qt.