CSC509 Lecture 06

Software Design
Quality Metrics
(202310)

Transcript

1. Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 508/9 Software Engineering (Design & Deployment) Lecture 06. Quality Metrics
2. Previously
3. Assignment 3 •Create a Desktop Application •Using Java SDK 20 (verbose programming language) •Java Swing for Graphics •User Experience (from installation configuration to using it)
4. 1. Java Desktop Application Eye Tr a cking Simul a tor (size, speed) 4
5. 2. Java Desktop Application A ff ect Recognition (speed) 5
6. 3. Java Desktop Application He a d Movement 6
7. 4. Java Desktop Application Cobot Simul a tor 7
8. 5. Java Desktop Application Hub 8
9. Quality Metrics
10. Clean Code Re a d a bility • DRY • KIS • SRP • Comments • Error H a ndling with a Logger 10 Metrics • LOC (eLOC, lLOC) • CC • A • I • D
11. Complexity Number Meaning 1-10 Structured and well written code High Testability Cost and Effort is less 10-20 Complex Code Medium Testability Cost and effort is Medium 20-40 Very complex Code Low Testability Cost and Effort are high >40 Not at all testable Very high Cost and Effort Cyclomatic Complexity 11
12. Cyclomatic Complexity • a round 20 is perfect, • up to 50 is f ine, • up to 100 is a cept a ble, • a bove 150 is prob a bly a “b a d” choice, a nd • more th a n 250 is 😖 12
13. Distance 13 Abstract Concrete Stable Hard to Change Only incoming dependencies Unstable Changeable Only outgoing dependencies the m ain sequence Painful Useless 0 1 1 0 Instability Abstractness
14. Instability • Indic a tes whether: ( a ) the item is m a inly used by others (st a ble – h a rd to ch a nge); or (b) it m a inly depends on other items (in-st a ble – ch a nge a ble). • It is a v a lue between 0 a nd 1: • 0 only incoming dependencies to • 1 (only outgoing dependencies). 14
15. Example 15 Write the Source Code
16. Patterns
17. GoF Patterns 17
18. Eric Gamma 18
19. Download Eclipse Modeling Tools 19
20. Factories and Sinletons package myModel; public interface MyModelFactory extends EFactory { MyModelFactory eINSTANCE = myModel.impl.MyModelFactoryImpl.init(); Course createCourse(); Student createStudent(); Computer createComputer(); MyModelPackage getMyModelPackage(); } public interface MyModelPackage extends EPackage { String eNAME = "myModel"; String eNS_URI = "https://org/eclipse/example/myModel"; String eNS_PREFIX = "org.eclipse.example.myModel"; MyModelPackage eINSTANCE = myModel.impl.MyModelPackageImpl.init(); // more ... } 20
21. Observers and Observables package myModel.impl; public class CourseImpl extends MinimalEObjectImpl.Container implements Course { protected static final String NAME_EDEFAULT = null; protected String name = NAME_EDEFAULT; protected EList<Student> students; protected CourseImpl() { super(); } @Override protected EClass eStaticClass() { return MyModelPackage.Literals.COURSE; } @Override public String getName() { return name; } @Override public void setName(String newName) { String oldName = name; name = newName; if (eNotificationRequired()) eNotify(new ENotificationImpl(this, Notification.SET, MyModelPackage.COURSE__NAME, oldName, name)); } // continue ... 21
22. To be Continued…
23. Questions 23
24. CSC 509 Software Engineering Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Fall 2024 Copyright. These slides can only be used as study material for the class CSC509 at Cal Poly. They cannot be distributed or used for another purpose.