CPS 108 l Object oriented design and programming

CPS 108 l Object oriented design and programming of medium-sized projects in groups using modern tools and practices in meaningful ways l High level OO concepts Ø XP: Extreme Programming: simplicity, refactor, grow code Ø Tell, don't ask: designing classes Ø Open/Closed: open to extension, closed to modification l Learn to manage time, improve coding methods, e. g. , can you really code effectively at 3: 00 am? Software Design 18. 1

Essential Design Patterns (by name) l l l MVC, aka Observer/Observable Ø Separate concerns, especially important for GUIs Composite Ø Container is/contains JComponent: File/Directory Factory Ø Separate creation from class, install new creators Proxy/Adapter Ø Stand-in with same interface, adapt interface as needed Decorator Ø Is-a and Has-a, e. g. , Filters and java I/O Command Ø Function/request object, undoable action Software Design 18. 2

Patterns continued l l l Singleton Ø Enforce single point of creation, conserve resources Template method Ø Hooks filled in by sublcasses Iterator Ø Common from previous courses, essential in Java Strategy Ø Human player, AI, change algorithm Forces in a problem lead to solution via appropriate pattern Ø Should know what GOF is: gang of four Software Design 18. 3

Something old, something new l CPS 108 has used Java since 1996 always with C++ Ø Before ’ 96 used Tcl/Tk or Python Ø In Fall '04 CPS 6/100 move to Java, consequences? Ø What is the purpose of CP S 108? l Is Unix an issue? Command-line? What about all Eclipse? Ø Do we need to use/understand the command line? l What about groups? Ø 110 model, keep same group always Ø 108 model, chaotic? Re-randomize? Always choice? Software Design 18. 4

Alan Kay, winner of 2004 Turing Award l Alto, Smalltalk, Squeak, Object. Oriented Programming "Don't worry about what anybody else is going to do… The best way to predict the future is to invent it. Really smart people with reasonable funding can do just about anything that doesn't violate too many of Newton's Laws!" Software Design 18. 5

Alan Kay on Education and OO l "By the time I got to school, I had already read a couple hundred books. I knew in the first grade that they were lying to me because I had already been exposed to other points of view. School is basically about one point of view -- the one the teacher has or the textbooks have. They don't like the idea of having different points of view, so it was a battle. Of course I would pipe up with my fiveyear-old voice. " l Java and C++ make you think that the new ideas are like the old ones. Java is the most distressing thing to hit computing since MSDOS. l I invented the term "Object-Oriented", and I can tell you I did not have C++ in mind. Software Design 18. 6

CPS 108 l l l Learn how to read Learn how to invent your own standards Learn to work in a group Learn about issues in developing programs and code Learn about design methodologies like XP l Lack of reflection Lack of feedback Lack of evaluated re-writing l How to fix? l l Software Design 18. 7

Future of Compsci 108 l Start with Java, end with C++? Ø Problems? Benefits? l Use Java, concentrate on web programming? Ø PHP? Other alternatives? l Where does it fit in Compsci/Engineering/Bioinformatics? Ø Should we be concerned about these? l Followup courses? Ø 109? Mentor? Software Design 18. 8