CSC307 Lecture 06

Introduction to Software Engineering
Clean Coding
(202407)

Transcript

1. Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 307 Introduction to Software Engineering Lecture 06. Clean Coding
2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
3. Homework 1. Due Monday: Quiz 2
4. Previously
5. Problem public class B implements E { public B() { C c1 = new C(); } public void method() { B b = new B(); b.sleep(); } } public class Y { A [] a = new A[5]; } public class A extends B { C c1, c2; public A() { c1 = new C(); } public void method() { D d = new D(); d.working(); } } public class X { public void m() { B var = new A(); double x – Math.sqrt(5); } }
6. Solution 6
7. CSC3100/Cloud-Services 7
8. More Tools
9. Tools We need a Tool
10. astah.net 10 https://astah.net/products/students/
11. File | New (projet) 11
12. Create Diagram | Class Diagram 12
13. Tools For the rest of this course Do your Class Diagrams in
14. Feedback A Paint App (version 1.0)
15. Do not forget User Experience 15
16. Clean unused lines 16
17. Clean unused lines 17
18. Caution using inheritance 18
19. Caution using inheritance 19
20. JavaDoc 20
21. JavaDoc 21
22. Recommended: Put a class in its own File 22
23. Feedback B Game of Life
24. How many objects in action 24
25. How many objects in action 25
26. How many objects in action 26
27. How many objects in action 27
28. How many objects in action 28
29. Constants, Parameters, Both 29
30. Thread, Runnable, and Timer 30 https:/ /github.com/CSC3100/Pacman
31. Clean Coding
32. Single Responsibility + Modularity • E a ch cl a ss or function should h a ve one, a nd only one, job. • Keep functions focused on a single t a sk. • Bre a k down your code into sm a ller, reus a ble modules or functions. • Ensure e a ch module or function h a s a cle a r, well-de f ined purpose. 32
33. Don't Repeat Yourself (DRY) • Avoid code duplic a tion by a bstr a cting common function a lity. • Use functions or cl a sses to enc a psul a te repe a ted jobs. 33
34. Keep It Simple (KIS) • Aim for simplicity in your design a nd implement a tion. • Avoid unnecess a ry complexity or over-engineering. 34
35. Refactoring • Regul a rly ref a ctor code to improve its structure a nd re a d a bility without ch a nging its function a lity. • Simplify complex code a nd elimin a te code smells. 35
36. Error Handling • Implement robust error h a ndling a nd logging mech a nisms. • Use exceptions a ppropri a tely a nd a void silent f a ilures - keep the user informed! 36
37. Performance Considerations • Write e ff icient code but prioritize re a d a bility a nd m a int a in a bility. • Optimize perform a nce-critic a l sections only when necess a ry. 37
38. Commenting and Documentation • Write me a ningful comments th a t expl a in why something is done, not wh a t is done. • Keep comments up to d a te with code ch a nges. • Document public APIs a nd complex logic thoroughly. 38
39. Consistent Formatting • Follow a consistent code style a nd form a tting guidelines. https://google.github.io/styleguide/javaguide.html • Use indent a tion, whitesp a ce, a nd comments e ff ectively to enh a nce re a d a bility. 39
40. Meaningful Names • Use descriptive a nd un a mbiguous n a mes for v a ri a bles, functions, cl a sses, etc. • Avoid using misle a ding or cryptic n a mes. • Follow consistent n a ming conventions. 40
41. Testing • Write a utom a ted tests to cover critic a l p a ths a nd edge c a ses. • M a int a in a comprehensive test suite a nd run it regul a rly. 41 To be continued…
42. Minimize Dependencies • Avoid unnecess a ry dependencies a nd keep extern a l libr a ries to a minimum. • Ensure dependencies a re up-to-d a te a nd well-m a n a ged. 42 To be continued…
43. Questions 43
44. Remember
45. Code is meant for human consumption 45
46. Manufacturing vs. Crafting
47. Together but not Scrambled
48. Lab 06. Clean Coding
49. Homework Due Monday: Paint-App 2.0
50. Homework 1. Clicking on a Shape allows you to select it. Then we can change its color by selecting a new one or Drag&Drop to change its location
51. Advice For selecting a line, consider something like this, then if the distance is "small" you can consider the line clicked (selected) // calculates the distance from P3(x3,y3) // to the line defined by P1(x1,y1) and P2(x2,y2) public static double distance (int x1, int y1, int x2, int y2, int x3, int y3) { double A = y2 - y1; double B = x1 - x2; double C = x2 * y1 - x1 * y2; double distance = Math.abs(A * x3 + B * y3 + C) / Math.sqrt(A * A + B * B); return distance; } 51
52. Homework 2. Drag&Drop. So, if the first click is on an empty space, we are drawing, but if the click is over an existing shape, we will drag it.
53. Homework 3. Add a menu Edit with the option Copy and the option Paste. By selecting a Shape and then Copy and then Paste a new Shape, to copied one appears 10px right and below the original one
54. Homework 4. KeyboardListener. For copy and paste, besides the menu Edit, we need CTRL+C and CTRL+V :)
55. Homework 5. File Menu. We should be able to save and Load our draws. Let’s also add the option New (for cleaning all).
56. Homework 6. We need Lines besides rectangle, Oval, and Arc.
57. Homework 7. Let’s add the About menu option and DialogBox
58. Homework 8. Last but not least, let’s fix the problem of drawing right-to-left or bottom-up
59. Homework 9. Do not forget the Class Diagram. Share it, i.e., include it in your submission
60. GUI 60
61. CSC 307 Introduction to Software Engineering Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Summer 2024 Copyright. These slides can only be used as study material for the class CSC307 at Cal Poly. They cannot be distributed or used for another purpose.