Changes to Qt Charts

Migrate Qt Charts to Qt 6.

Qt 6 is a result of the conscious effort to make the framework more efficient and easy to use.

We try to maintain binary and source compatibility for all the public APIs in each release. But some changes were inevitable in an effort to make Qt a better framework.

In this document we summarize those changes in Qt Charts.

QtCharts Namespace

Qt Charts no longer has a custom QtCharts namespace. Instead, the normal Qt namespace is used if one is configured for the Qt build.

OpenGL Acceleration in QML

As the name implies, AbstractSeries.useOpenGL still only supports OpenGL acceleration, so it won’t work if QML RHI backend is defined as something else, as it typically is by default in Qt 6. Force RHI OpenGL backend into use to fix this issue by using the environment variable QSG_RHI_BACKEND=opengl, for example.