1. 1 CS 691z/791z Topics in Software Engineering Chapter 13: Activity Diagrams & Chapter 19: Basic Statecharts [Arlow and Neustadt, 2002] March 8, 2007

2. 2 Outline Activity diagrams: Actions and subactivity states Transitions Decisions, forks, and joins Swimlanes and object flows Signals Basic statecharts: Syntax States Transitions Events

3. 3 Activity Diagrams: Actions & Subactivities. Actitivity diagrams: Actitivity diagrams: A form of “OO flowcharts,” a particular case of statecharts A form of “OO flowcharts,” a particular case of statecharts Attached to modeling elements to describe behavior Attached to modeling elements to describe behavior Typically related to use cases, classes, components, collaborations, operations & methods Typically related to use cases, classes, components, collaborations, operations & methods Contain actions (atomic, uninterruptible, instantaneous) and sub-activities (non-atomic, interruptible, may take time) Contain actions (atomic, uninterruptible, instantaneous) and sub-activities (non-atomic, interruptible, may take time) Examples of actions, Fig. 13.2 [Arlow & Neustadt]: Examples of actions, Fig. 13.2 [Arlow & Neustadt]:

4. 4 Activity Diagrams:.Actions & Subactivities Actions: Start and stop states, Fig. 13.3 [Arlow & Neustadt, 2002] Subactivities: Examples, Fig. 13.4 [Arlow & Neustadt, 2002]

5. 5 Activity Diagrams: Transitions Transitions in activity diagrams, Fig. 13.5 [Arlow &Neustadt, 2002] Transitions in activity diagrams occur when the states finish their work

6. 6 Activity Diagrams: Decisions Decisions in activity diagrams, Fig. 13.6 [Arlow & Neustadt, 2002]

7. 7 Activity Diagrams: Forks and Joins Fig. 13.7 [Arlow & Neustadt, 2002] Activity diagrams allow modeling concurrent workflows

8. 8 Activity Diagrams: Swimlanes Fig. 13.8 [Arlow & Neustadt, 2002] Swimlanes are typically used for use cases, business modeling, and workflow modeling

9. 9 Activity Diagrams: Object Flows Fig. 13.9 [Arlow & Neustadt, 2002] Activities may input and output objects and may modify object states

10. 10 Activity Diagrams: Signals Fig. 13.10 [Arlow & Neustadt, 2002] A signal is a package of information transferred asynchronously between objects

11. 11 Statecharts There are two main modeling elements in statecharts: states and transitions. Example of a simple state machine, Fig. 19.2 [Arlow & Neustadt]

12. 12 Statecharts: Syntax Summary of UML state syntax, Fig.19.3 [Arlow & Neustadt, 2002]

13. 13 Statecharts: Transitions Summary of UML transition syntax, Fig.19.4 [Arlow & Neustadt, 2002] Where: Event = internal or external occurrence that triggers the transition Guard condition = boolean expression, when true transition allowed Action = some operation that takes place when the transition fires

14. 14 Statecharts: Events…. Events can be of four types: Call event Signal event Change event Time event

15. 15 Statecharts:.Events… Example of a call event, Fig.19.6 [Arlow & Neustadt, 2002]

16. 16 Statecharts:..Events.. Example of signal event Fig.19.7 [Arlow & Neustadt, 2002] Modeling the receipt a signal Fig.19.8 [Arlow & Neustadt, 2002]

17. 17 Statecharts: …Events. Example of a change event, Fig.19.9 [Arlow & Neustadt, 2002]

18. 18 Statecharts: ….Events Example of a time event, Fig.19.10 [Arlow & Neustadt, 2002]

19. 19 Statecharts: What next? An advanced statechart [Ch. 20, Fig. 20.4, Arlow & Neustadt, 2002]

20. 20 Extra: Analysis classes vs. Design classes Fig.15.2 [Arlow & Neustadt, 2002]