1. Informatics 122 Software Design II
Lecture 11 André van der Hoek
Duplication of course material for any commercial purpose without the explicit written permission of the professor is prohibited.
May 20, 2019 – 22:13:49
(c) 2006 University of California, Irvine – André van der Hoek

2. © 2006 University of California, Irvine – André van der Hoek
Today’s Lecture
Reverse engineering
Design – Implementation – Reverse Engineering
Brief recap
Feedback
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

3. © 2006 University of California, Irvine – André van der Hoek
Reverse Engineering
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

4. Design – Implementation – Reverse Engineering
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© 2006 University of California, Irvine – André van der Hoek

5. Review: Design Diamond
Domain of Materials
Domain of Use
Knowledge
Representation
Ideas
Activity
concern
manipulates
informs
Goal
captures
enhances
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

6. System and Implementation Design
System design
describes what the software system should do
focus towards addressing Goal and Domain of Use
“How do we fundamentally approach the problem?”
typically represents an intermediate “design in progress”
architecture design can be part of system design
Implementation design
describes what the implementer should do
focus towards addressing Domain of Materials
“How do we make the approach reality?”
typically represents a final “completed design”
module design can be part of implementation design
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

7. Goals of Implementation Design
Provide a shared plan to follow
consistency
Ensure the plan meets its recipients’ needs
helpfulness
Ensure the solution is appropriate
effectiveness
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

8. From Informatics 121 to Informatics 122
To date, much of our focus has been on system design
creative thinking
learning to rely on colleagues
incomplete specifications
no implementation
Now, it is time to turn our attention to implementation design
nuts and bolts (but still some creative thinking)
specifying for colleagues (but still relaying some on colleagues)
complete specifications
implementation
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

9. © 2006 University of California, Irvine – André van der Hoek
But How to Get There?
Practice, practice, practice…
Examples, examples, examples…
Some guidelines exist
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

10. Patterns Apply Two Design Principles
Program to an interface, not an implementation
interface should be separately defined, using abstract classes
Favor object composition over inheritance
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

11. Original Catalogue of Patterns
Purpose
Creational
Structural
Behavioral
Scope
Class
Abstract Method
Adapter (class)
Interpreter Template Method
Object
Abstract Factory Builder Prototype Singleton
Adapter (object) Bridge Composite Decorator Façade Flyweight Proxy
Chain of Responsibility Command Iterator Mediator Memento Observer State Strategy Visitor
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

12. Abstract Factory (Creational, Object)
It isolates concrete classes
It makes exchanging product families easy.
It promotes consistency among products.
Supporting new kinds of products is difficult.
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

13. How Much Design Is Too Much Design?
low
likelihood of future changes
high
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© 2006 University of California, Irvine – André van der Hoek

14. Assignment 2a: Basic Structure
Implement the game “Theseus and the Minotaur” according to the UML design provided on the course web site
You are free to make any updates to the design you desire, but if you do so they must be properly documented and your implementation has to follow your new design
A sample running version of the game is available on the web
compared to this game, we do not use walls, but blocks to delineate possible paths
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

15. Assignment 2b: Basic Structure
Design and implement a modified version of the game “Theseus and the Minotaur”
You may use your design from Assignment 2a as the basis, but you may also build an entirely new design from scratch, as long as all your decisions are properly documented and your implementation follows your new design
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

16. © 2006 University of California, Irvine – André van der Hoek
Assignment 3
Refine the official design of Theseus and the Minotaur (as provided on the course web site) by
furnishing any missing classes, methods, and local variables
applying design patterns to improve the structure of the design
Deliverables
a print-out of your final UML design
a print-out of your design rationale
which critical decisions did you make, and why?
Print-outs are to be handed in in class
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

17. © 2006 University of California, Irvine – André van der Hoek
Design Recovery
Recovered abstractions need:
formal specifications
module breakdowns
data abstractions
dataflows
informal knowledge
All information required to understand
what
how
why
(Biggerstaff, 1989)
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© 2006 University of California, Irvine – André van der Hoek

18. © 2006 University of California, Irvine – André van der Hoek
Cake Recovery
How difficult was this?
Why?
What would have helped more:
Access to BnA/Archstudio design docs
Access to running code
Another 5 days of time
Rather have done something Jetris-like?
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

19. A Critical Design Tradeoff
full control
full understanding flexibility competitive advantage
can be instantaneous external support
quality
build (and thus design)
buy or get for free (and thus fit into a design)
time cost
maintenance standards
evaluation cost licensing lack of customizability obsolescence urgent bugs
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

20. Component Reuse Process
Identify preliminary architecture
Identify potential places for reuse
Establish selection criteria (per place)
Update architecture
Select component
Evaluate components
Search for applicable components
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

21. © 2006 University of California, Irvine – André van der Hoek
Assignment 5
Research available components that provide a particular kind of functionality for a layered software design environment, set up selection criteria, and make a choice of the component that you believe is best
Create a 15 minute presentation that describes
your search process
candidate components you found
strengths
weaknesses
your selection criteria
the component you deem best (and why)
a (rough) architecture
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

22. © 2006 University of California, Irvine – André van der Hoek
Final Project
System
Design
Arch.
Imp.
Code
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

23. © 2006 University of California, Irvine – André van der Hoek
Assignment 6 – Groups
Group 1:
MIKE WADHERA, MITCH WILLIAMS, JULIE RICO, SAM ARCHER, SAM CHANG
a mini spreadsheet
Group 2:
KYLE STRASSER, CHRIS BAKER, SEAN CASHIN, JAMES GARY, NICK INGERSOLL
a mini database
Group 3:
GABRIELA MARCU, ANGELO PIOLI, BRYANT HORNICK, NG WENG LEONG, PETER LEE
a mini web authoring tool
Group 4:
JUNG HO KIM, CYNTHIA K. LAM, MICHELLE ALVAREZ, JASON DRAMBY
a mini slide authoring and presentation tool
Focus on a simple implementation
all projects need to be able to save and open files
we will guide you during Monday’s meetings, adaptability
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek

24. © 2006 University of California, Irvine – André van der Hoek
In Closing…
Thanks for a fun (albeit very busy) quarter
If you have feedback on the class, I would love to hear it (both positive and negative; after all, this was a first)
Do not forget to fill out the online course evaluations
May 20, 2019 – 22:13:49
© 2006 University of California, Irvine – André van der Hoek