Inheritance or Composition

These slides are the material that I use as support on my talk about Inheritance and Composition on Android.

Transcript

1. ≥ Welcome!
2. ≥ Txus Ballesteros Android Engineer @txusballesteros +txusballesteros github.com/txusballesteros
3. ≥ Green Programming™
4. ≥ Programming focused on nature aspects.
5. ≥ ≥
6. ≥ Hi, I’m Ramón. ≥
7. ≥ ≥
8. ≥ ≥
9. ≥ Sorry for the Fake!!!
10. ≥ Inheritance or Composition?
11. ≥ Composition or Composition
12. ≥ ≥
13. ≥ ≥
14. ≥ Client Behaviour Behaviour Behaviour Behaviour Client Client Client Inheritance Strategy
15. ≥ Client Behaviour Behaviour Behaviour Behaviour Client Composition Strategy
16. ≥ Inheritance
17. ≥ Inheritance common mistakes • Early adoption. • Architecture based 100% on inheritance.
18. ≥ Inheritance Bad Smells • Having infinite levels of inheritance. • Extents of a non abstract classes. • Base classes with more than 100 200 lines.
19. ≥ Some responsibility mistakes…
20. ≥ Activity.java Android Donut: 3.629 lines of code https://github.com/android/platform_frameworks_base/blob/donut-release/core/java/android/app/Activity.java Android KitKat: 5.468 lines of code https://github.com/android/platform_frameworks_base/blob/kitkat-release/core/java/android/app/Activity.java Android Marshmallow: 6.649 lines of code https://github.com/android/platform_frameworks_base/blob/marshmallow-release/core/java/android/app/Activity.java
21. ≥ Fragment.java Android ICS MR1: 1.564 lines of code https://github.com/android/platform_frameworks_base/blob/ics-mr1-release/core/java/android/app/Fragment.java Android KitKat: 1.920 lines of code https://github.com/android/platform_frameworks_base/blob/kitkat-release/core/java/android/app/Fragment.java Android Marshmallow: 2.559 lines of code https://github.com/android/platform_frameworks_base/blob/marshmallow-release/core/java/android/app/Fragment.java
22. ≥ TextView.java Android Donut: 7.317 lines of code https://github.com/android/platform_frameworks_base/blob/donut-release/core/java/android/widget/TextView.java Android KitKat: 9.231 lines of code https://github.com/android/platform_frameworks_base/blob/kitkat-release/core/java/android/widget/TextView.java Android Marshmallow: 10.194 lines of code https://github.com/android/platform_frameworks_base/blob/marshmallow-release/core/java/android/widget/TextView.java
23. ≥ How I can take the decision?
24. ≥ S O L I D RP Single Responsibility CP Open Close SP Liskov Substitution SP Interfaces Segregation IP Dependency Inversion
25. ≥ S O L RP Single Responsibility CP Open Close SP Liskov Substitution
26. ≥ Composition
27. ≥ Where can you use composition?
28. ≥ Everywhere… “You're using composition and you don't know it”
29. ≥ Let’s Start…
30. ≥ Views & ViewGroups
31. ≥ List & RecyclerViews
32. ≥ List Adapter List using adapters…
33. ≥ List Renderer List composing with renderers… Renderer Renderer Renderer
34. ≥ Fragments
35. ≥ Activity Fragment Fragments most common usage…
36. ≥ Activity Fragment Fragment Fragments activities composition…
37. ≥ Activity Fragment Fragment Fragment Fragment Fragments activities composition…
38. ≥ Activity Fragment Fragments activities composition…
39. ≥ Activity Fragment Fragments activities composition… Activity Activity
40. ≥ Activities
41. ≥ Toolbar Activity composing Activities… +
42. ≥ Activity composing Activities… Activity AbsActivity Activity
43. ≥ Activity composing Activities… Loading Activity Activity Toolbar FAB
44. ≥ Tools
45. ≥ Java 8 & Defaults
46. ≥ Mara https://github.com/txusballesteros/mara
47. ≥ We’re Hiring jobs@wallapop.com
48. ≥ Thanks for Coming