I have found it much more difficult to figure out how to take this UI model and map it onto process control applications, which are of primary interest to me. In such applications, there is an external process, operating asynchronously with the program, that sends (conceptually, at any rate) updates that should be reflected on the display, so that the user remains aware of the state of the process.
Such applications seem to map less cleanly onto the CLIM model, and *may* fit more nicely onto constraint-based UI frameworks like Garnet and whatever that cells thing is...
All you really have to do is modify your object and get REDISPLAY to run. This happens by default when :incremental-redisplay is true and the object modification is the result of a command (including some command invoked by define-presentation-to-command-translator).
Look at Examples/stopwatch.lisp to see how an external process can cause the display to be updated.
Paul