ACT ONE, Scene 2: In Which We Deign to Design

Now what about design? Assuming you've got a conceptual model from your analysis in the form of a few use cases and a few class diagrams, your design should follow from this. In object-oriented design, you now need to firm up the class designs, decide on the methods your classes will contain, determine the relationships between the classes, and figure out how each of the methods will do what it's supposed to do.

In our current example, we've decided on four classes, BirdFeeder, FeedingDoor, Sensor, and RemoteControl. The first three classes we've already developed, so the question here is do we need to change any of these classes in order to integrate the RemoteControl class into the program? Figure 9-2 shows what we've got right now.