Event-driven programming under MFC

The Microsoft Foundation class library is still a popular library with which to write Microsoft Windows-based desktop programs. It does have some support for web programming if we mix ActiveX Template Library (ATL) along with it. Being a C++ library, MFC uses a mechanism called Message Mapping to handle events. A sample event handling table given as macros is part of every MFC program:

BEGIN_MESSAGE_MAP(CClockFrame,CFrameWnd)
    ON_WM_CREATE()
    ON_WM_PAINT()
    ON_WM_TIMER()
END_MESSAGE_MAP()

The preceding message map will respond to OnCreate, OnPaint, and Ontimer standard Windows API messages. Deep down these message maps are arrays on to which we will use message id as an index for dispatching the events. On closer examination, it is not much different from the standard Windows API messaging model.

The code listing is not given here because we have globally a GUI implementation of one of the key interfaces for the Reactive Programming model using MFC. The implementation is based on the MFC library and the reader can go through the annotated listing to gain an understanding of non-trivial event processing in MFC.