Content Provider, usando

 Para usar o Content Provider MyLocationProvider definido no último post, vamos tomar como base a mesma aplicação que testamos em diversos posts anteriores.

 O app tem as seguintes características:

 1. A activity inicia lendo os dados existentes no Content Provider e os mostra numa ListView. Para isso usamos um ManagedQuery, como o cursor resultante da leitura será gerenciado, o ListView será atualizado automaticamente quando o Content Provider for alterado.
 Usamos um ListAdapter extendido de um CursorAdapter para tratar os dados do cursor.
 A leitura dos dados é feita com um Limit de 20 linhas para ficar mais rápido e exemplificar o uso da clausula no db. A ordem é decrescente de data. O último location gravado é o primeiro do ListView.
 No método onStart é iniciado o service para coleta dos dados dos Locations Providers.
 Temos tres botões:
 .Start - inicia a coleta de dados no service
 .Stop - para a coleta de dados no service
 .Clear DB - Deleta todos os registros existentes no Content Provider

 2. No service:
 .Uso da tecnica produtor/consumidor para gravar os dados através de uma worker thread.
 .Uso de uma BlockingQueue para passar os Locations da thread principal para o thread consumidora
 .A worker thread é iniciada no onBind e fica aguardando os Locations para gravar no Content Provider
 .Uso da tecnica de controle do encerramento de uma thread através do envio de um objeto indicativo de fim

 Vamos aos códigos:

 AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="br.agorandroid.mylocationprovider" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="7" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <provider android:exported="false" android:authorities="br.com.agorandroid.mylocation.provider" android:name="MyLocationProvider"> <grant-uri-permission android:pathPattern=".*"/> </provider> <activity android:name=".MyLocationActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name=".MyLocationService" ></service> </application> </manifest>

main.xml
<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:weightSum="1"> <TextView android:id="@+id/status" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center_horizontal" android:text=""/> <linearlayout android:orientation="horizontal" android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="wrap_content"> <button android:layout_width="wrap_content" android:id="@+id/start" android:layout_weight="1" android:text="Start" android:layout_height="wrap_content"></Button> <button android:layout_width="wrap_content" android:id="@+id/clear" android:layout_weight="1" android:text="Clear DB" android:layout_height="wrap_content"></Button> <button android:layout_width="wrap_content" android:id="@+id/stop" android:layout_weight="1" android:text="Stop" android:layout_height="wrap_content"></Button> </LinearLayout> <view android:layout_height="2dip" android:layout_width="fill_parent" android:background="#ff909090" /> <listview android:id="@+id/listView1" android:layout_height="0dip" android:layout_width="fill_parent" android:layout_weight="1"> </ListView> </LinearLayout>

linhalista.xml
<?xml version="1.0" encoding="utf-8"?> <TableLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content"> <tablerow > <textview android:text="TextView" android:id="@+id/textView1" android:layout_weight="1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView> <textview android:text="TextView" android:id="@+id/textView2" android:layout_weight="1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView> </TableRow> <tablerow > <textview android:text="TextView" android:id="@+id/textView3" android:layout_weight="1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView> <textview android:text="TextView" android:id="@+id/textView4" android:layout_weight="1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView> </TableRow> </TableLayout>

ListAdapter.java /** * */ package br.agorandroid.mylocationprovider; import java.text.SimpleDateFormat; import java.util.Date; import android.content.Context; import android.database.Cursor; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.CursorAdapter; import android.widget.TextView; /** * @author A H Gusukuma * * agorandroid.blogspot.com */ public class ListAdapter extends CursorAdapter { private final SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss"); /** * @param context * @param c */ public ListAdapter(Context context, Cursor c) { super(context, c); // TODO Auto-generated constructor stub } @Override public void bindView(View view, Context ctx, Cursor cur) { TextView tv1 = (TextView) view.findViewById(R.id.textView1); tv1.setText("Lat: " + (double) cur.getDouble(cur.getColumnIndex(MyLocation.Locations.COLUMN_NAME_LATITUDE))); TextView tv2 = (TextView) view.findViewById(R.id.textView2); tv2.setText("Long: " + (double) cur.getDouble(cur.getColumnIndex(MyLocation.Locations.COLUMN_NAME_LONGITUDE))); TextView tv3 = (TextView) view.findViewById(R.id.textView3); tv3.setText(sdf.format(new Date(cur.getLong(cur.getColumnIndex(MyLocation.Locations.COLUMN_NAME_TIME))))); TextView tv4 = (TextView) view.findViewById(R.id.textView4); tv4.setText(cur.getString(cur.getColumnIndex(MyLocation.Locations.COLUMN_NAME_PROVIDER)) +" "+ cur.getFloat(cur.getColumnIndex(MyLocation.Locations.COLUMN_NAME_ACCURACY))); } @Override public View newView(Context context, Cursor cursor, ViewGroup parent) { // TODO Auto-generated method stub LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); View v = inflater.inflate(R.layout.linhalista, null); return v; } }

MyLocationActivity.java package br.agorandroid.mylocationprovider; import android.app.Activity; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.os.IBinder; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import br.agorandroid.mylocationprovider.MyLocationService.LocalBinder; /** * @author A H Gusukuma * * agorandroid.blogspot.com */ public class MyLocationActivity extends Activity { final private int MAX_LISTVIEW = 20; private ListAdapter listAdapter; private ListView listView; private MyLocationService mService; boolean mBound = false; private TextView tv; private Cursor cursor; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button button = (Button)findViewById(R.id.start); button.setOnClickListener(mStartListener); button = (Button)findViewById(R.id.clear); button.setOnClickListener(mClearListener); button = (Button)findViewById(R.id.stop); button.setOnClickListener(mStopListener); tv = (TextView) findViewById(R.id.status); Uri mUri = MyLocation.Locations.CONTENT_URI; cursor = managedQuery(mUri.buildUpon().appendQueryParameter (MyLocation.Locations.LIMIT_PARAMETER_KEY, String.valueOf(MAX_LISTVIEW)).build(), null, null, null, null); listView = (ListView) findViewById(R.id.listView1); listView.setStackFromBottom(true); listAdapter = new ListAdapter(this, cursor); listView.setAdapter(listAdapter); } @Override protected void onStart() { super.onStart(); if (!mBound) { Intent intent = new Intent(this, MyLocationService.class); bindService(intent, mConnection, Context.BIND_AUTO_CREATE); } } @Override protected void onPause() { super.onPause(); tv.setText(""); if (mBound) { mService.stopColeta(); } } @Override protected void onStop() { super.onStop(); if (mBound) { unbindService(mConnection); mBound = false; } } protected void onDestroy() { super.onDestroy(); if (mBound) { unbindService(mConnection); mBound = false; } } private OnClickListener mStartListener = new OnClickListener() { public void onClick(View v) { if (mBound) { tv.setText("Coleta iniciada"); mService.startColeta(); } } }; private OnClickListener mClearListener = new OnClickListener() { public void onClick(View v) { int count = getContentResolver().delete(MyLocation.Locations.CONTENT_URI, "1", null); Toast.makeText(MyLocationActivity.this, String.valueOf(count) + " rows deleted" , Toast.LENGTH_LONG).show(); } }; private OnClickListener mStopListener = new OnClickListener() { public void onClick(View v) { if (mBound) { tv.setText("Coleta finalizada"); mService.stopColeta(); } } }; private ServiceConnection mConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName className, IBinder service) { LocalBinder binder = (LocalBinder) service; mService = binder.getService(); mBound = true; } @Override public void onServiceDisconnected(ComponentName className) { tv.setText("Coleta finalizada"); mBound = false; } }; }

MyLocationService.java /** * */ package br.agorandroid.mylocationprovider; import java.util.List; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import android.app.Service; import android.content.ContentResolver; import android.content.ContentValues; import android.content.Context; import android.content.Intent; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Binder; import android.os.Bundle; import android.os.IBinder; import android.util.Log; /** * @author A H Gusukuma * * agorandroid.blogspot.com */ public class MyLocationService extends Service { private final IBinder mBinder = new LocalBinder(); private LocationManager lm; public class LocalBinder extends Binder { MyLocationService getService() { return MyLocationService.this; } } private BlockingQueue<location> queue = new LinkedBlockingQueue<location>(10); private final Location LOCATION_END = new Location("END"); private Thread mThread; private LocationListener myLocationListener = new LocationListener() { public void onLocationChanged(Location location) { Location mLocal = new Location(location); try { queue.put(mLocal); } catch (InterruptedException e) { } } public void onProviderDisabled(String provider) { } public void onProviderEnabled(String provider) { } public void onStatusChanged(String provider, int status, Bundle extras) { } }; @Override public IBinder onBind(Intent intent) { // TODO Auto-generated method stub lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE); mThread = new Thread(new WriteLocation()); mThread.start(); return mBinder; } public void startColeta() { // lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, myLocationListener); List<string> providersEnabled; providersEnabled = lm.getProviders(true); if (providersEnabled.size() > 0) { for (int i=0; i<providersEnabled.size(); i++) { String prov = providersEnabled.get(i); lm.requestLocationUpdates(prov, 0, 0, myLocationListener); } } } public void stopColeta() { lm.removeUpdates(myLocationListener); } @Override public void onDestroy() { while (true) { try { queue.put(LOCATION_END); break; } catch (InterruptedException e) { } } } private class WriteLocation implements Runnable { @Override public void run() { while(true) { Location location; try { location = queue.take(); if (location == LOCATION_END) { break; } ContentValues initialValues = new ContentValues(); initialValues.put(MyLocation.Locations.COLUMN_NAME_PROVIDER, location.getProvider()); initialValues.put(MyLocation.Locations.COLUMN_NAME_TIME, location.getTime()); initialValues.put(MyLocation.Locations.COLUMN_NAME_ACCURACY, location.getAccuracy()); initialValues.put(MyLocation.Locations.COLUMN_NAME_LATITUDE, location.getLatitude()); initialValues.put(MyLocation.Locations.COLUMN_NAME_LONGITUDE, location.getLongitude()); ContentResolver cr = getContentResolver(); cr.insert(MyLocation.Locations.CONTENT_URI, initialValues); } catch (InterruptedException e) { // ignore } } } } }

Algumas observações finais:
 .Normalmente não gravamos todos os Locations recebidos, fazemos uma seleção dos mais precisos, por tempo, etc.
 .Ou, definimos critérios para os providers nos enviar somente os locations em conformidade com os mesmos.
 .O metodo ManagedQuery está deprecated a partir do API 11, Android 3.0.x
 .Foi substituído pelo CursorLoader
 .O acesso aos dados para o ListView está na UI Thread, se ficar muito demorado usar uma AsyncTask.
 .Não testei o método update

Vejam o resultado, no Xperia mini:

 Abraços