Wednesday, October 24, 2007

Example of the Command Pattern

After first reading about the command pattern, I did not realize that I have used it many times before this. Since the command pattern deals with encapsulating actions as objects, I thought a good place to look for this pattern was a program dealing with user interaction. I pulled up some of my old homework assignments from CMSI 370 (Interaction Design) and noticed that ActionListener was what I was looking for. ActionListener is the same as the Command class that is used in the diagrams in the book, Design Patterns: Elements of Reusable Object-Oriented Software. And the actionPerformed() method is the Execute() method.

1 comment:

Dondi said...

As discussed when you mentioned this to me verbally, ActionListener certainly reflects the core idea behind the Command design pattern, but there is something else that can be viewed as a "full-blown" implementation of the pattern. We eventually got it, long before you typed this blog, so I'm a little surprised that it isn't mentioned in this entry.