Design Patterns Summer Course 2009-2010 - Session#4
- 1. Lecture #4 Ahmed Safwat Muhamad Hesham Abdelrahman Al-Ogail
- 2. What about Singleton? Call for a new requirement. First try implementation. Meet today’s pattern. Second try implementation. Common uses. Project Description. What’s after all of this?
- 3. What have we did till now?
- 4. You: Dad, I need pocket money. Dad: *^^%^&@&**&^#&*%&*#%
- 7. sign in Offline Available available busy away available away Away Busy busy All states are connected to offline via sign out
- 9. Out of No Pepsi Money insert pepsi > 0 money eject pepsi = 0 money Pepsi Has Sold Money order pepsi
- 10. reach cliff after a while Running Idle
- 11. I want the enemy turn crazy when you collect a gem. If you touch the enemy while it is crazy, you die and it turns idle again. Double crazy enemy speed by 4 times once.
- 12. reach cliff after a while Running Idle gem gem collected collected player died Crazy
- 13. What do you think we need do this time ?
- 14. Violates Open Closed Princible. Not object oriented. Further additions will cause bugs. State transitions are buried between if-else.
- 15. Exploring the pattern Let’s Google it!
- 17. Explaining the pattern Pattern class diagram
- 19. Pac-Man
- 20. Keyboard with Shift Key
- 21. Windows Live Mail (Offline/Online)
- 22. Pattern’s Challenge Try it yourself Strategy/State conflict Challenge: What are the differences between State and Strategy Pattern?
- 23. What’s Next Further Reading State Pattern: Chapter 10 in Head First Strategy Pattern: Chapter 1 in Head First GoF: Behavioral Pattern Section Section: enhance way of drawing shapes