4.12FXB.MessageTypes.THEME

(This section is irrelevant to scripts and UDIXes because they have no user interface of their own. It is only applicable to widgets.)

The user can change the graphical theme of the software - e.g. from dark to light - while it is running, without a restart. Therefore, the theme can change while your widget is running.

The THEME message notifies you that this has happened. The FXB.Message object will contain a Theme object, but it is simplest to inspect the change just by using Framework.Theme.