android mypractices

Android Best PracticesMurat Yener, eteration

Wednesday, May 23, 12

Why am I doing this talk?

Get well soon Alain!!


Alternatives

• Make me look like Alain?

• or just let me do another talk...


pointed ears

science officer

half human - half vulcan

trying to understand human nature

rounded ears

developer

half flex - half java

trying to understand objective-c behaviour


how to develop?

• Android SDK: Java, capable, resources, easy

• Android NDK: Most capable but??

• Adobe AIR: easy XML+AS but??!!

• runtime, memory, new apis

• Web+JS


SDK

• Activities

• Services

• Widgets

• Intents&Broadcasts

• Preferences


Going to Market

• Silence my Phone vs Shake to Answer

• idea

• target devices

• code right

• let users communicate with you

• respond back... (even when you don’t care)


Targeting all devices

• Matching everyone is winner!

• bug!! v5 thinks its v6

• canary pattern


Targeting all Devices

• Never, ever manipulate images!!!

• Ok, only if you must...

• nine-patches


app fitness

• Collect you own trash!

• Services, unregister whatever registered

• Images: image=null != image.recycle();

• favor primitives over objects

• BUT!! avoid autoboxing

• keep in mind Generics only work for objects

• size checks on loops


things that take time

• Specially when network is involved

• Never, ever lock up UI thread!!!

• Painless threading: Use AsyncTasks

• Let user know: Toaster


Responsive UI

• use as little as possibles views in views: slower layout, drawing, startup time...

• cut down view hierarchy: memory, slow, StackOverFlowException


Less Views??

• use Merge as root tag for components

• use RelativeLayout instead of LinearLayout


class AndroidWay extends Activity { TextView name; ImageView thumbnail; LocationManager loc; Drawable icon; String myName;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); name = (TextView) findViewById(R.id.name); thumbnail = (ImageView) findViewById(R.id.thumbnail); loc = (LocationManager) getSystemService(Activity.LOCATION_SERVICE); icon = getResources().getDrawable(R.drawable.icon); myName = getString(R.string.app_name); name.setText( "Hello, " + myName ); } } class RoboWay extends RoboActivity { @InjectView(R.id.name) TextView name; @InjectView(R.id.thumbnail) ImageView thumbnail; @InjectResource(R.drawable.icon) Drawable icon; @InjectResource(R.string.app_name) String myName; @Inject LocationManager loc;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); name.setText( "Hello, " + myName ); } }

DI in Android!!

• findViewById is expensive!

• either use it once or... RoboGuice!!


...


@EActivity(R.layout.translate) // Sets content view to R.layout.translatepublic class TranslateActivity extends Activity { @ViewById // Injects R.id.textInput EditText textInput;

@ViewById(R.id.myTextView) // Injects R.id.myTextView TextView result;

@AnimationRes // Injects android.R.anim.fade_in Animation fadeIn;

@Click // When R.id.doTranslate button is clicked void doTranslate() { translateInBackground(textInput.getText().toString()); } @Background // Executed in a background thread void translateInBackground(String textToTranslate) { String translatedText = callGoogleTranslate(textToTranslate); showResult(translatedText); } @UiThread // Executed in the ui thread void showResult(String translatedText) { result.setText(translatedText); result.startAnimation(fadeIn); }

AndroidAnnotations


</presentation>

[email protected]/yenermdevchronicles.com

blogs.eteration.com/blogs


mailto:[email protected]

mailto:[email protected]

android mypractices

Technology

icon myname

android sdk

icon drawable icon

thumbnail imageview

easy android ndk

void dotranslate

servi icon

slower layout