android - Why my ContentObserver is not being called when I send an SMS?

Question

I am trying to detect when a SMS is sent. I have searched on the web and on StackOverflow and all seems to be the same solution. I have a simple Activity that starts a Service and in the service I am trying to detect when a SMS is sent:

MainActivity.java

import android.os.Bundle;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;
import android.view.Menu;

public class MainActivity extends Activity {

    Intent serviceIntent;
    private static MyReceiver mServiceReceiver; 

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

    @Override
    protected void onPause() {
        Log.i("Status","Pause");
        unregisterReceiver(mServiceReceiver);
        super.onPause();
    }

    @Override
    protected void onResume() {
        Log.i("Status","Resume");

        // Inicio el Servicio
        serviceIntent = new Intent(MainActivity.this, TrackerService.class);
        startService(serviceIntent);
        // Registro el broadcast del Service para obtener los datos
        mServiceReceiver = new MyReceiver();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(TrackerService.mAction);
        registerReceiver(mServiceReceiver, intentFilter);

        super.onResume();
    }

    /**
     * Receiver del Service, aqui se obtienen los datos que envia el Service
     */
    private class MyReceiver extends BroadcastReceiver{
        @Override
        public void onReceive(Context arg0, Intent arg1) {
            Log.i("ServiceReceiver", "onReceive()");
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

TrackerService.java

import android.app.Service;
import android.content.ContentResolver;
import android.content.Intent;
import android.database.ContentObserver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Handler;
import android.os.IBinder;
import android.util.Log;

public class TrackerService extends Service{

    // Nombre del service
    public static final String mAction = "SMSTracker";
    ContentResolver content;
    ContentResolver contentResolver;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("Status","Service Start");

        // ContentResolver para obtener los SMS salientes
        contentResolver = this.getContentResolver();
        contentResolver.registerContentObserver(Uri.parse("content://sms/out"), true, new mObserver(new Handler()));

        return super.onStartCommand(intent, flags, startId);
    }

    /**
     * Observer que obtiene los SMS salientes
     */
    class mObserver extends ContentObserver {

        public mObserver(Handler handler) {
            super(handler);
        }

        @Override
        public void onChange(boolean selfChange) {
            super.onChange(selfChange);
            Log.i("Status","onChange");

            Uri uriSMS = Uri.parse("content://sms/out");
            Cursor cur = contentResolver.query(uriSMS, null, null, null, null);
            Log.i("SMS", "Columns: " + cur.getColumnNames());

            cur.moveToNext();
            String smsText = cur.getString(cur.getColumnIndex("body"));

            Log.i("SMS", "SMS Lenght: " + smsText.length());

        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("Status","Service Destroy");
    }

    @Override
    public IBinder onBind(Intent intent) {
        Log.i("Status","Service Bind");
        return null;
    }

}

Manifest

<uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />
    <uses-permission android:name="android.permission.RECEIVE_SMS"></uses-permission>
    <uses-permission android:name="android.permission.READ_SMS"></uses-permission>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    <service android:name=".TrackerService" />

</application>

According to my LogCat the service is started and I can see it in running services in my Android phone onChange() method inside my service is never called when I send an sms. Is something I am missing ?

Answer 1

If you replace content://sms/out by content://sms/, you'll see that the ContentObserver is not called when the SMS is sent but when one is received. Here is the code of my observer. It only enters onChange(boolean) when receiving a SMS. The protocol is "0" at that time.

So, I am struck at the same point as you :(

class SmsProviderObserver extends ContentObserver {

    public SmsProviderObserver(Handler handler) {
        super(handler);
    }

    @Override
    public void onChange(boolean selfChange) {
        super.onChange(selfChange);

        Uri uriSms = Uri.parse("content://sms/");

        ContentResolver cr = getContentResolver();
        Cursor cur = cr.query(uriSms, null, null, null, null);
        // this will make it point to the first record, which is the last
        // SMS sent
        if (!cur.moveToNext()) {
            return; // weird!
        }

        String protocol = cur.getString(cur.getColumnIndex("protocol"));
        if (protocol == null) {
            // send
            Log.i("SMS", "SMS SEND");
            int threadId = cur.getInt(cur.getColumnIndex("thread_id"));

            Log.i("SMS", "SMS SEND ID = " + threadId);
            Cursor c = cr.query(
                    Uri.parse("content://sms/outbox/" + threadId), null,
                    null, null, null);
            c.moveToNext();
            int p = cur.getInt(cur.getColumnIndex("person"));
            Log.i("SMS", "SMS SEND person= " + p);
            // getContentResolver().delete(Uri.parse("content://sms/conversations/"
            // + threadId), null, null);

        } else {
            // receive
            Log.i("SMS", "SMS RECIEVE");
            int threadIdIn = cur.getInt(cur.getColumnIndex("thread_id"));

            cr.delete(
                    Uri.parse("content://sms/conversations/" + threadIdIn),
                    null, null);
        }
    }
}

And the code registering the observer:

ContentResolver contentResolver = getContentResolver();
mSmsObserverHandler = new Handler();
mSmsProviderObserver = new SmsProviderObserver(mSmsObserverHandler);
contentResolver.registerContentObserver(Uri.parse("content://sms/"), true, mSmsProviderObserver);