Google Developers Study Jam: Android for Beginners. Final Project Summary

Transcript

1. Google Developers Study Jam Android for Beginners. Final Projects Constantine Mars Co-Organizer @ GDG Dnipropetrovs’k Senior Developer @ DataArt constantine.mars@gmail.com +ConstantineMars
2. Agenda • Summary • Common mistakes and issues • Best examples • Certificates ceremony • Group photo :)
3. Stats Started Jam: 62 Final projects completed: 22 Discussion projects: 8
4. Common mistakes
5. UX • Mixing different languages (i.e. English + Latin) • Mixing color styles • Making too many elements in UI • Adding extra controls
6. XML • Auto-indent, rearrange code before commit • Don’t left empty tags • Don’t mix +id and onClick method name in the same tag • Keep single color and size style for icons • Don’t use Layout.background to display images, use ImageView with ScaleType • Use Styles
7. Code duplication, copy-paste Thing thing = new Thing(); thing.setPrice(20); thing.setColor(RED); Thing thing2 = new Thing(); thing2.setPrice(25); thing.setColor(GREEN); Better: Thing thing = new Thing(20, RED); Thing thing2 = new Thing(25, GREEN); Or Thing thing = Thing.newInstance(20, RED); Thing thing2 = Thing.newInstance(25, GREEN);
8. Long chain of calls adapter.addFragment(SomeFragment.newInstance(list.get(i)),list.get(i).getName()); Better: adapter.addFragment( SomeFragment.newInstance(list.get(i)), list.get(i).getName() ); *use: • Spaces • New line • Auto-indent • Rearrange code
9. Usage of design patterns public class ClassicSingleton { private static ClassicSingleton instance = null; protected ClassicSingleton() { // Exists only to defeat instantiation. } public static ClassicSingleton getInstance() { if(instance == null) { instance = new ClassicSingleton(); } return instance; } }
10. Fragments • Pattern Fragment.newInstance() • .onCreateView() - don’t load assets here • Interaction with Activity - get callback in .onAttach() • Flexible UI, master-detail
11. Common sense • Unused folders, “test”, “androidTest” • Don’t put apk to github code, use Github Release feature • Don’t put different projects in one repo
12. Best examples
13. Good practices • Spanned text, Html.fromHtml() • Menu.setShadowLayer() • Fragments • RecyclerView with CardView • Animations with alpha, translate • Real names for .apk • Be on Discussion Forum • Getting Real - making cool app, using only what you really know
14. Cool design, true OOP, ViewPager
15. OOP, Design, Database, ORM
16. Transparent, original design
17. RecyclerView with CardView
18. Good OOP and Design
19. First in discussion
20. San Francisco
21. Animation With alpha
22. Getting Real Discussion, simple, but robust
23. И еще много проектов, которые мы не успеем сегодня посмотреть и обсудить... Но они наверняка будут скоро на Discussion - И их увидит весь мир :)
24. Certificates
27. Let’s take photo :) +ConstantineMars