Android best practices

Android Best

Practices

José Manuel Ortega

DroidCon July 2014

https://techfest.uc3m.es/programa/android-in-practice/

Index

UI DESIGN

INCLUDES / REUSING LAYOUTS

STYLES

ACTION BAR SEARCH VIEW / PROGRESS BAR

ACCESSIBILITY / TALLBACK

NETWORK CONNECTION

ASYNCTASK / SERVICES

FRAGMENTS

NAVIGATION PATTERNS

GEOLOCATION / PERFORMANCE

DEPENDENCY INYECTION / ANNOTATIONS

TOOLS / VOLLEY / LIBRARIES / /BOOKS

http://developer.android.com/intl/es/training/index.html

UI Design

http://developer.android.com/design/index.html

Ways to specify the size of an item:

dp/dip: Density independent pixel.

sp/sip: Scale independent pixel.Used in font sizes.

pt: Point.

px: Pixel. Not use

layout_width,layout_height

match_parent:takes all the space available.

wrap_content: uses the space needed

fill_parent:equivalent to match_parent

Android Asset Studio

Generate icons and graphic elements for each resolution http://android-ui-utils.googlecode.com/hg/asset-studio/dist/index.html

Resources /Screen support

External elements you want to include and reference in the application. Declaratively include in /res ,accesing by @<type>/<nname> Are programmatically accessible via the R class (compiled with Android Asset Packaging Tool)

Android automatically selects the resource that adapts to the environment

Each resource type in a folder / res.

drawable: Images, Icons. layout: Layout to organize views. values: string.xml: Text strings colors.xml dimens.xml: font sizes,margins,paddings anim: Animations raw: Other resources like audio or video menu: Menus and dialogs xml: Other xml (preferences, app widget, …)

<supports-screens android:anyDensity="true" android:xlargeScreens="true" android:largeScreens="true" android:normalScreens="true" android:smallScreens="true" />

Includes / Reusing layouts

Styles

<!-- estilo para TextView --> <style name="CodeStyleTextView" parent="@android:style/TextAppearance.Medium"> <item name="android:layout_width">match_parent</item> <item name="android:layout_height">wrap_content</item> <item name="android:paddingTop">50dp</item> <item name="android:textColor">@color/negro</item> <item name="android:background">@color/gris_claro</item> <item name="android:textSize">35sp</item> </style>

<!-- estilo para Button--> <style name="CodeStyleButton" parent="android:Widget.Button"> <item name="android:layout_width">match_parent</item> <item name="android:layout_height">wrap_content</item> <item name="android:textSize">20sp</item> <item name="android:drawableTop">@drawable/logo_empresa</item> </style>

Styles

<TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/info_empresa" style="@style/CodeStyleTextView" /> <Button android:id="@+id/btnChangeImage" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/cambiar_imagen_fondo" style="@style/CodeStyleButton" />

Action Bar Search View

Action Bar Search View

@Override public boolean onCreateOptionsMenu(Menu menu) { mSearchView = (SearchView) searchItem.getActionView(); mSearchView.setQueryHint("Search..."); mSearchView.setOnQueryTextListener(this); return true; }

<item android:id="@+id/action_search" android:showAsAction="always" android:title="@string/search" android:icon="@android:drawable/ic_menu_search" android:actionViewClass= "android.support.v7.widget.SearchView" />

private SearchView mSearchView;

Action Bar Search View

Implement interface OnQueryTextListener

Override methods onQueryTextSubmit, onQueryTextChange

@Override public boolean onQueryTextSubmit(String query) { UniversityListFragment fragmentList = (UniversityListFragment)getSupportFragmentManager().findFragmentByTag("list_fragment"); fragmentList.searchData(query); return true; } @Override public boolean onQueryTextChange(String query) { return true; }

ACTION BAR PROGRESS Avoid modal Dialogues and Activities Always update the user on progress(ProgressBar and ProgressDialog) Render the main view and fill in data as it arrives

ACTION BAR PROGRESS

Progress bar in Action Bar while url loading

private Activity activity = this; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.getWindow().requestFeature(Window. FEATURE_INDETERMINATE_PROGRESS); ActionBar ab = getSupportActionBar(); ……… }

activity.setProgressBarIndeterminateVisibility(true);

viewer.setWebViewClient(new WebViewClient() {

public void onPageFinished(WebView view, String url) {

activity.setProgressBarIndeterminateVisibility(false);

}

Show the progress bar to start loading and hide when finished.

Accessibility / TalkBack

Accessibility

http://developer.android.com/training/accessibility/index.html

<Button android:id="@+id/button" android:src="@drawable/button" android:contentDescription="@string/text_description"/>

Through layout

Through code

label.setContentDescription(getText(R.string.text_description));

Focus navigation. Next view to receive focus when user navigates

<EditText android:id="@id/editText" android:layout_alignBottom="@+id/button" android:layout_toLeftOf="@id/button" android:nextFocusUp="@+id/button" android:nextFocusDown="@+id/button" android:nextFocusLeft="@+id/button" android:nextFocusRight="@+id/button" android:nextFocusForward="@+id/button"/>

Network connection

import android.net.ConnectivityManager; import android.net.NetworkInfo; ConnectivityManager connectivityManager; connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo(); Boolean connected = networkInfo != null && networkInfo.isAvailable() && networkInfo.isConnected();

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

Network connection Enable Wifi / Check connection type

NetworkInfo wifiInfo=connectivityManager.getNetworkInfo (ConnectivityManager.TYPE_WIFI); NetworkInfo mobileInfo = connectivityManager.getNetworkInfo (ConnectivityManager.TYPE_MOBILE); if(wifiInfo.isConnected()){ Toast.makeText(context, "Wifi is connected", Toast.LENGTH_LONG).show(); } if(mobileInfo.isConnected()){ Toast.makeText(context, "3G/4G is connected", Toast.LENGTH_LONG).show(); }

WifiManager wifiManager=(WifiManager) context.getSystemService(Context.WIFI_SERVICE); wifiManager.setWifiEnabled(true);

<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>

Network connection HTTP Request HttpGet httpGet = new HttpGet("http://www.google.com"); HttpParams httpParameters = new BasicHttpParams(); int timeoutConnection = 3000; HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection); int timeoutSocket = 5000; HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket); DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters); try { Log.d("isNetworkAvailable", "Checking network connection..."); httpClient.execute(httpGet); Log.d("isNetworkAvailable", "Connection OK"); return true; } catch (ClientProtocolException e) {e.printStackTrace(); } catch (IOException e) {e.printStackTrace(); } return false;

Responsive

Avoid ANR(Application Not Responding) No response to an input event (such as key press or

screen touch events) within 5 seconds. Do not block the main UI thread with heavy work Web Service call, Http Request

Communication with UI Thread is made with: • Thread / Handler • ThreadPoolExecutor • AsyncTask

Goal of AsyncTask is to take care of thread management for you.

Asynctask This class will allow us to perform background tasks without using neither directly nor

Handlers Threads, trying these elements in a fully transparent way to the programmer. When we define a AsyncTask class must define the type of three elements, the input

parameters, its progress and outcome. Override onPreExecute(),doInBackground(),onPostExecute(),onProgressUpdate()

class RequestTask extends AsyncTask<String, String, String>{ @Override protected void onPreExecute() { } @Override protected void onProgressUpdate(Integer... values) { } @Override protected String doInBackground(String... uri) { } @Override protected void onPostExecute(String result) { super.onPostExecute(result); }

new RequestTask().execute(url);

Services

Perform the activity in an AsyncTask. Kill the service when the task is complete. Leaving a service running when it’s not needed is one of the

worst memory management mistakes an Android app can make.

Service problem is always execute in main thread. The best way to limit the lifespan of your service is to use an

IntentService, which finishes itself as soon as it's done handling the intent that started it.

IntentService always execute in own thread. Allows to launch a service in a new thread, avoiding blocking

the main thread. Example:ActivityRecognitionService

Fragments

A fragment represents a certain behavior or a portion of a user interface activity.

Multiple fragments can be combined. A fragment must always be part of an activity. They emerged to provide greater flexibility to build the user interface Override methods @Override //called when finish onCreate method in activity public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); } @Override public void onCreate(Bundle savedInstanceState) {//inicializar componentes super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) { }

http://developer.android.com/guide/components/fragments.html

Fragments

Add a fragment to view by layout xml <?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="horizontal">

<fragment

class="com.proyecto.spaincomputing.fragment.UniversidadesFragment"

android:id="@+id/FrgListado"

android:layout_width="375dp"

android:layout_height="match_parent"/>

<fragment

class="com.proyecto.spaincomputing.fragment.FragmentDetalle"

android:id="@+id/FrgDetalle"

android:layout_width="match_parent"

android:layout_height="match_parent"/>

</LinearLayout>

Fragments

Add a fragment to view

By code //Fragments array Fragment[] fragments = new Fragment[]{new PortadaFragment(), new UniversityListFragment(),new UniversidadesImagesFragment()}; FragmentManager manager = getSupportFragmentManager(); manager.beginTransaction() .add(R.id.contentFrame, fragments[0]) .add(R.id.contentFrame, fragments[1]) .add(R.id.contentFrame, fragments[2]) .commit(); //show/hide manager.beginTransaction().show(fragments[0]).commit(); manager.beginTransaction().hide(fragments[1]).commit(); manager.beginTransaction().hide(fragments[2]).commit();

Fragments/ Master-detail

PORTRAIT LANDSCAPE

Fragments/ Master-detail

PORTRAIT

LANDSCAPE

Fragments/ Master-detail

2 layout layout\fragment_universidades_list.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="wrap_content" > </ListView> </LinearLayout>

Fragments/ Master-detail

2 layout layout-land\fragment_universidades_list.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:baselineAligned="false" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:orientation="horizontal" tools:context=".TabsActivity" > <ListView android:id="@+id/listView" android:layout_width="0px" android:layout_height="wrap_content" android:layout_weight="1.5"> </ListView> <fragment android:id="@+id/fragmentUniversidadInfo" android:name="com.proyecto.spaincomputing.fragment.UniversidadInfoFragment" android:layout_width="0px" android:layout_height="wrap_content" android:layout_weight="4" tools:layout="@layout/fragment_universidad_info" /> </LinearLayout>

Fragments/ Master-detail

Check orientation to display the detail page UniversidadBean ub=listado.get(position); if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) { FragmentManager manager = getActivity().getSupportFragmentManager(); UniversidadInfoFragment fragment = (UniversidadInfoFragment) manager.findFragmentById(R.id.fragmentUniversidadInfo); fragment.loadWebViewContent(ub.getEnlace()); getActivity().invalidateOptionsMenu(); } else { Intent intent = new Intent(getActivity().getApplicationContext(), UniversityDetailActivity.class); intent.putExtra(UniversityDetailActivity.URL, ub.getEnlace()); url=ub.getEnlace(); intent.putExtra(UniversityDetailActivity.UNIVERSIDAD, ub.getNombre()); startActivity(intent); }

Navigation patterns Navigation drawer View Pager Tabs navigation in Action Bar actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

Drop-down Navigation in Action Bar

actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);

NavUtils in library support

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/pager" android:layout_width="wrap_content" android:layout_height="wrap_content"/>

Navigation Drawer http://developer.android.com/training/implementing-navigation/nav-

drawer.html

View Pager

http://developer.android.com/intl/es/training/animation/screen-slide.html

Tabs navigation in Action bar

http://developer.android.com/intl/es/guide/topics/ui/actionbar.html#Tabs

Drop-down navigation in Action bar

http://developer.android.com/intl/es/guide/topics/ui/actionbar.html#Dropdown

NavUtils

import android.support.v4.app.NavUtils; NavUtils.navigateUpTo(this, new Intent(this, ListadoActivity.class));

http://developer.android.com/design/patterns/navigation.html

Intent intent = NavUtils.getParentActivityIntent(this); intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP| Intent.FLAG_ACTIVITY_SINGLE_TOP); NavUtils.navigateUpTo(this, intent);

NavUtils.navigateUpFromSameTask(this);

<activity android:name=".DetalleUniversidadActivity" android:parentActivityName=".ListadoActivity" <!-- Parent activity meta-data to support 4.0 and lower --> <meta-data android:name="android.support.PARENT_ACTIVITY" android:value=".ListadoActivity" /> </activity>

Singleton Application class

<application android:allowBackup="true" android:icon="@drawable/icon" android:label="@string/app_name" android:theme="@style/Theme.Styled" android:name= "com.proyecto.spaincomputing.singleton.MySingleton">

public class MySingleton extends Application { private static MySingleton instance; public static Context context; public static MySingleton getInstance(Context context){ if (instance == null) { // Create the instance instance = new MySingleton(context.getApplicationContext()); } return instance; } @Override public void onCreate() { super.onCreate(); context = getApplicationContext(); }}

Adapter Pattern

Link between the source data and the view It works with ListView or GridView There are many types of adapter You can perform a custom adapter The most used ArrayAdapter / CursorAdapter The Adapter interacts with a collection of data objects for display in

View

ArrayList<UniversidadBean> listado=newArrayList<UniversidadBean>(); private ListView lstListado; lstListado=(ListView)getView().findViewById (R.id.LstListado); lstListado.setAdapter (new UniversidadAdapter(this,listado));

View Holder/View Container Pattern

ViewContainer

static class ViewContainer{

public ImageView imagen;

public TextView nombre;

public TextView descripcion;

}

Improve the performance of listview

The viewholder is used to avoid calling findViewById whenever prompted a new row to the adapter. Thus, instead of calling findViewById each time you use the references to the fields you have stored in the viewholder.

This pattern will help us to limit the number of calls to findViewById method. The idea would be to call it once, and then save the view daughter that refers to the instance of ViewHolder to be associated with the object by the method convertView View.setTag ()

Its recommend using a static class to store the items of each row in the view, functioning as a kind of cache for our view.

View Holder/View Container Pattern

@Override

public View getView(int position, View convertView,ViewGroup parent) {

ViewContainer viewContainer;

//si es la primera vez que se imprime la fila

if(convertView==null){

LayoutInflater inflater = context.getLayoutInflater();

convertView = inflater.inflate(R.layout.row, null,true);

//crea una vista para el objeto contenedor

viewContainer=new ViewContainer()

//obtiene una referencia a todas las vistas de la fila

viewContainer.nombre=(TextView)convertView.findViewById(R.id.textView_superior);

viewContainer.descripcion=(TextView)convertView.findViewById(R.id.textView_inferior);

viewContainer.imagen=(ImageView)convertView.findViewById(R.id.imageView_imagen);

//asigna el contenedor de la vista a rowView

convertView.setTag(viewContainer);

}else{

viewContainer=(ViewContainer) convertView.getTag(); //recicling }

//personaliza el contenido de cada fila basándone en su posición

viewContainer.nombre.setText(listado.get(position).getNombre());

viewContainer.descripcion.setText(listado.get(position).getDescripcion());

viewContainer.imagen.setImageResource(listado.get(position).getIdImagen());

return(convertView);

}

View Holder/View Container Pattern

Debug

Criteria Geolocation

LocationManager / android.location package ACCESS_COARSE_LOCATION/ACCESS_FINE_LOCATION

//Obtain Location Manager LocationManager locationManager = (LocationManager)this.getSystemService (Context.LOCATION_SERVICE); Criteria criteria = new Criteria(); //criteria.setAccuracy(Criteria.ACCURACY_FINE); //GPS criteria.setAccuracy(Criteria.ACCURACY_COARSE); // WIFI criteria.setPowerRequirement(Criteria.POWER_LOW); criteria.setAltitudeRequired(false); criteria.setBearingRequired(false); criteria.setSpeedRequired(false); criteria.setCostAllowed(false); String provider = locationManager.getBestProvider(criteria, true); // In order to make sure the device is getting the location, request // updates [wakeup after changes of: 5 sec. or 10 meter] locationManager.requestLocationUpdates(provider, 5, 10, this); locationBridge.setNewLocation(locationManager.getLastKnownLocation(provider));

Obtain user moving LocationListener onLocationChanged()

Activity Recognition API

<uses-permission android:name="com.google.android-gms.permission.ACTIVITY_RECOGNITION"/>

<service android:name="ActivityRecognitionService"/>

IntentFilter filter = new IntentFilter(); filter.addAction("com.example.myactivityrecognition.ACTIVITY_RECOGNITION_DATA"); registerReceiver(receiver, filter);

Register broadcast receiver on activity

Obtain user moving / ActivityRecognitionService public class ActivityRecognitionService extends IntentService { @Override protected void onHandleIntent(Intent intent) { if(ActivityRecognitionResult.hasResult(intent)){ ActivityRecognitionResult result = ActivityRecognitionResult.extractResult(intent); Intent i = new Intent("com.example.myactivityrecognition.ACTIVITY_RECOGNITION_DATA"); i.putExtra("Activity", getType(result.getMostProbableActivity().getType()) ); i.putExtra("Confidence", result.getMostProbableActivity().getConfidence()); sendBroadcast(i); } } private String getType(int type){ if(type == DetectedActivity.UNKNOWN) return "Unknown"; else if(type == DetectedActivity.IN_VEHICLE) return "In Vehicle"; else if(type == DetectedActivity.ON_BICYCLE) return "On Bicycle"; else if(type == DetectedActivity.ON_FOOT) return "On Foot"; else return ""; } }

Performance / Save Battery life

Useful for background tracking applications

Use “PASSIVE_PROVIDER” LocationProvider (instead of “GPS_PROVIDER”)

LocationListener has three primary settings: “provider” positioning technology (e.g. GPS, NETWORK) “minTime” requested time (milliseconds) between location

updates “minDistance” requested distance (m) that triggers updates

if (user_moving){

-Decrease LocationListener “minTime” } else{ if(Stopped for a reasonable amount of time){ -Increase LocationListener “minTime” } }

Performance /Instruction count

Debug.InstructionCount icount =new Debug.InstructionCount(); icount.resetAndStart(); ………. if(icount.collect()){ Log.d("DEBUG","Total instructions executed"+icount.globalTotal()); Log.d("DEBUG","Method invocations"+icount.globalMethodInvocations()); }

DEPENDENCY INYECTION

RoboGuice / Dagger / ButterKnife RoboGuice is a framework that brings the simplicity and ease of

Dependency Injection to Android.

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); name = (TextView) findViewById(R.id.name); myName = getString(R.string.app_name); name.setText("Hello, " + myName); }

@ ContentView(R.layout.main) class MyActivity extends RoboActivity{ @InjectView(R.id.name) TextView name; @InjectView(R.id.thumbnail) ImageView thumbnail; @InjectResource(R.drawable.icon) Drawable icon; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); name.setText("Hello, " + myName); }}

ButterKnife

Eliminate findViewById calls by using @InjectView Eliminate anonymous inner-classes for listeners by annotating

methods with @OnClick

class ExampleActivity extends Activity { @InjectView(R.id.name) EditText name; @OnClick(R.id.submit) void submit() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.simple_activity); ButterKnife.inject(this); } }

https://github.com/JakeWharton/butterknife

Annotations @EActivity(R.layout.translate) // Sets content view to R.layout.translate public 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); }

http://androidannotations.org/

Features Check for API availability before using features

PackageManager pm = getPackageManager(); boolean hasCamera = pm.hasSystemFeature(PackageManager.FEATURE_CAMERA); if (hasCamera) { // do things that require the camera } boolean hasBlueTooth = pm.hasSystemFeature(PackageManager.FEATURE_BLUETOOTH); if (hasBlueTooth) { // do things that require the blueTooth }

<uses-feature android:name="android.hardware.bluetooth"/> <uses-feature android:name="android.hardware.camera"/>

Restore state in activity

• If you support both orientations, save the instance state while orientation changes for more responsiveness.

Before finish() an activity, onSaveInstanceState() is called to save UI state.

Restore the Activity state after being created

@Override public void onSaveInstanceState(Bundle savedInstanceState) { // Always call the superclass so it can save the view hierarchy state super.onSaveInstanceState(savedInstanceState); }

public void onRestoreInstanceState(Bundle savedInstanceState) { // Always call the superclass so it can restore the view hierarchy super.onRestoreInstanceState(savedInstanceState); }

LINT

Android comes with a tool called lint that can be used for identifying and correcting structural problems with your code.

Each detection has an associated description and severity level so it can be prioritized.

Can be invoked directly from the command-line, automated build system or directly from Eclipse

VOLLEY

https://android.googlesource.com/platform/frameworks/volley https://github.com/mcxiaoke/android-volley

Unzip and import from Eclipse as a new project with code available. Export the project as Java Volley / jar checking only the "src" folder.

Volley is a library that facilitates and speeds up the creation of applications

that make use of networking in Android handling concurrency and network requests.

The advantage is that volley is responsible for managing the request threads

transparently to the developer.

libs\volley.jar Objects RequestQueue

Request: Contains all the necessary details of API calls to Web. For example,

the method to use (GET or POST), application data, listeners, error listeners.

VOLLEY REQUEST

import com.android.volley.*; public static RequestQueue requestQueue; @Override protected void onCreate(Bundle savedInstanceState) { requestQueue = Volley.newRequestQueue(this); }

JSON Request with volley.Request object

JsonObjectRequest jsObjRequest = new JsonObjectRequest(Request.Method.GET, url, null, successListener,null); requestQueue.add(jsObjRequest);

Instagram Activity

VOLLEY RESPONSE

//Callback that is executed once the request has completed Response.Listener<JSONObject> successListener = new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { } }

JSON Response by volley.Response object

More volley examples https://github.com/PareshMayani/Android-Volley-Example

Images

LRU Cache

Other libraries

https://github.com/nostra13/Android-Universal-Image-Loader

• Universal Image Loader

http://square.github.io/picasso/

• Picasso

Volley image loader

public InstagramImageAdapter(Context context, ArrayList<InstagramImage> dataArray) { this.dataArray = dataArray; this.inflater = LayoutInflater.from(context); this.imageLoader = new ImageLoader(InstagramActivity.requestQueue, new BitmapLRUCache()); }

private InstagramImageAdapter adapter; private ArrayList<InstagramImage> imagArray; imagArray=new ArrayList<InstagramImage>(); adapter=new InstagramImageAdapter(this,imagArray); Response.Listener<JSONObject> successListener = new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { JSONArray data = response.getJSONArray("data"); imagArray.addImage(data); }

Developer libraries in google play

Libraries

Indicator in ViewPager http://viewpagerindicator.com/

https://github.com/chrisbanes/ActionBar-PullToRefresh

Pager Sliding Tabstrip https://github.com/astuetz/PagerSlidingTabStrip Show routes in map. https://github.com/tyczj/MapNavigator

Sliding Menu

Library to implement a sliding flyout with similar behavior to navigation drawer

https://github.com/jfeinstein10/SlidingMenu

MessageBar

Library to improve toast messages http://simonvt.github.io/MessageBar/

Fading Action Bar

Used in Google play music https://github.com/ManuelPeinado/FadingActionBar

+

http://www.androidviews.net/ http://www.androidpatterns.com/

Books

About me

https://github.com/jmortega/apps https://github.com/jmortega/android

https://www.linkedin.com/in/jmortega1

@jmortegac

https://play.google.com/store/apps/developer?id=Jos%C3%A9+Manuel+Ortega+Candel

https://speakerdeck.com/jmortega/