Sometimes, it is easy to lose sight of your original goals when developing an application. We have been so focused on adding all sorts of bells and whistles to this project that we have forgotten about its most important purpose: the editing of storm cells and their tracks. Our application, so far, is strictly a data viewer, and a limited one at that. We are not able to interrogate the display for more information about the features we see, nor are we able to save our changes, much less even make any changes. We demonstrated a track deletion feature back in the beginning of the chapter, but that information could not be linked back to the source dataset for modification.

It is at the beginning of an application development that one must be very careful. It is very easy to conflate the display with the data, as we have already done. Conflating data and display can cause two kinds of problems. First, your data can become tied up in some obscure, inscrutable display object that...