Hi,
maybe I did not fully get your question (what you tried or what is not working).
Anyway, let me express another thought:
A Device Class (and its corresponding Device Driver) is the interface between the GUI application and a certain software API (= your middleware, your business logic).
Resources and string constants are aspects of the GUI application and should be handled GUI internally. From an interface perspective, a middleware should report only a certain system state to the GUI application and should not assign bitmap resources.
Maybe it is better to introduce some system states and let the GUI react accordingly. See also the chapter Implementing a Device Interface.
Does this help?
Best regards,
Manfred.