What does the “Global include” checkbox mean in the Promoted Widgets dialog?

Question

I never check it when promoting widgets, and everything works, but I've always wondered what it is for. Does anyone know?

Answer 1

Checking this box leads to the header file being included as a global header file in the generated ui code. I.e. it will be included as #include <foowidget.h> instead of #include "foowidget.h".

For example, you'll need to use it if you want to promote a widget to a custom widget from a library if the library is installed system-wide but you cannot directly create that widget in the designer. An example would be to promote a QSlider to a QxtSpanSlider if you install Qxt via the linux package manager.