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Google Developers Study Jam
Android for Beginners. Final Projects
Constantine Mars
Co-Organizer @ GDG Dnipropetrovs’k
Senior Developer @ DataArt
[email protected]
+ConstantineMars
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Agenda
● Summary
● Common mistakes and issues
● Best examples
● Certificates ceremony
● Group photo :)
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Stats
Started Jam: 62
Final projects completed: 22
Discussion projects: 8
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Common
mistakes
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UX
● Mixing different languages (i.e. English + Latin)
● Mixing color styles
● Making too many elements in UI
● Adding extra controls
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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
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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);
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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
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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;
}
}
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Fragments
● Pattern Fragment.newInstance()
● .onCreateView() - don’t load assets here
● Interaction with Activity - get callback in .onAttach()
● Flexible UI, master-detail
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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
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Best examples
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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
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Cool design,
true OOP, ViewPager
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OOP, Design,
Database, ORM
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Transparent,
original design
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RecyclerView with
CardView
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Good OOP and
Design
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First in discussion
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San Francisco
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Animation
With alpha
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Getting Real
Discussion, simple, but
robust
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И еще много проектов, которые мы не
успеем сегодня посмотреть и обсудить...
Но они наверняка будут скоро на Discussion
- И их увидит весь мир :)
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Certificates
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No content
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Let’s take photo :)
+ConstantineMars