The state pattern allows an object to change its behavior when its internal state changes. The context maintains a reference to a state object that defines the current state. Concrete state subclasses implement specific behaviors for each of the context's possible states. The state pattern is commonly used in game development where objects like characters can have multiple states like idle, running, jumping etc. that trigger different behaviors.

1. Joshua Candish

2. What is the state design pattern
How does it work
When to use it/What it does for us
An industry use of the pattern
Research Poster
Code walkthrough

3. It allows an object to alter its behaviour
when its internal state changes.

4. Context: The context maintains an instance of a
concrete state subclass that defines the current
state
State: Defines an interface for encapsulating the
behaviour associated with a particular state of
the context.
Concrete State: Each subclass implements a
behaviour associated with a state of context.

6. Not many negatives
Gaming makes good use
Easy to test

7. States: Raise, Transfer, Pay, Reconcile, etc...
Interactions: Play, Rewind, Replay, etc...

9. Abd-El-Hafiz, ,S.K., Shawky, D. M., & El-Sedeek, A. (2008). Recovery of object-oriented design
patterns using static and dynamic analyses. International Journal of Computers &
Applications, 30(3), 220-233. Retrieved from ProQuest.
Freeman, E., & Robson, E., & Bates, B., & Sierra, J. (2004) Head first design patterns. O’Reilly
Media.
Gamma, E., & Helm, R., & Johnson, R., & Vlissides, J. (1995) Design patterns: Elements of
reusable object-oriented software. Addison-Wesley Publishing Company.
Seiter, L. M., Palsberg, J., & Lieberherr, K. J. (1998). Evolution of object behavior using context
relations. IEEE Transactions on Software Engineering, 24(1), 79-92. Retrieved from ProQuest.
State .NET design pattern. (2014). Retrieved 28 August 2014 from
www.dofactory.com/net/state-design-pattern
Derek Banas. (2012, October, 16). State design pattern. Retrieved 28 August from
www.youtube.com/watch?v=MGEx35FjBu