How to detect incoming calls, in an Android device

Question

I'm trying to make an app like, when a call comes to the phone I want to detect the number. Below is what I tried, but it's not detecting incoming calls.

I want to run my MainActivity in background, how can I do that?

I had given the permission in manifest file.

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

Is there anything else should I provide in the manifest?

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test_layout);
   }

   public class myPhoneStateChangeListener extends PhoneStateListener {
       @Override
       public void onCallStateChanged(int state, String incomingNumber) {
           super.onCallStateChanged(state, incomingNumber);
           if (state == TelephonyManager.CALL_STATE_RINGING) {
               String phoneNumber =   incomingNumber;
           }
       }
   }
}

Answer 1

private MyPhoneStateListener phoneStateListener = new MyPhoneStateListener();

to register

TelephonyManager telephonyManager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
telephonyManager.listen(phoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);

and to unregister

TelephonyManager telephonyManager = (TelephonyManager) getSystemService(TELEPHONY_SERVICE);
telephonyManager.listen(phoneStateListener, PhoneStateListener.LISTEN_NONE);

Answer 2

With Android P - Api Level 28: You need to get READ_CALL_LOG permission

Restricted access to call logs

Android P moves the CALL_LOG, READ_CALL_LOG, WRITE_CALL_LOG, and PROCESS_OUTGOING_CALLS permissions from the PHONE permission group to the new CALL_LOG permission group. This group gives users better control and visibility to apps that need access to sensitive information about phone calls, such as reading phone call records and identifying phone numbers.

To read numbers from the PHONE_STATE intent action, you need both the READ_CALL_LOG permission and the READ_PHONE_STATE permission. To read numbers from onCallStateChanged(), you now need the READ_CALL_LOG permission only. You no longer need the READ_PHONE_STATE permission.

Answer 3

@Gabe Sechan, thanks for your code. It works fine except the onOutgoingCallEnded(). It is never executed. Testing phones are Samsung S5 & Trendy. There are 2 bugs I think.

1st: a pair of brackets is missing.

//....
case TelephonyManager.CALL_STATE_IDLE: 
            //Went to idle-  this is the end of a call.  What type depends on previous state(s)
            if(lastState == TelephonyManager.CALL_STATE_RINGING){
                //Ring but no pickup-  a miss
                onMissedCall(context, savedNumber, callStartTime);
            }
            else{ // this one is missing
                if(isIncoming){
                      onIncomingCallEnded(context, savedNumber, callStartTime, new Date());                       
                }
                else{
                      onOutgoingCallEnded(context, savedNumber, callStartTime, new Date());                                               
                }
            }// this one is missing
            break;
//..

2nd: "lastState" is not updated by the "state" if it is at the end of the function. It should be replaced to the first line of this function by

public void onCallStateChanged(Context context, int state, String number) {
    int lastStateTemp = lastState;
    lastState = state;
    // todo replace all the "lastState" by lastStateTemp from here.
    if(lastStateTemp  == state){
        //No change, debounce extras
        return;
    }
    //....

Additional I've put "lastState" and "savedNumber" into shared preference as you suggested.

Just tested it with above changes. Bug fixed at least on my phones.

Answer 4

this may helps you and also add require permision

public class PhoneListener extends PhoneStateListener
{
    private Context context;
    public static String getincomno;

    public PhoneListener(Context c) {
        Log.i("CallRecorder", "PhoneListener constructor");
        context = c;
    }

    public void onCallStateChanged (int state, String incomingNumber)
    {

        if(!TextUtils.isEmpty(incomingNumber)){
        // here for Outgoing number make null to get incoming number
        CallBroadcastReceiver.numberToCall = null;
        getincomno = incomingNumber;
        }

        switch (state) {
        case TelephonyManager.CALL_STATE_IDLE:

            break;
        case TelephonyManager.CALL_STATE_RINGING:
            Log.d("CallRecorder", "CALL_STATE_RINGING");
            break;
        case TelephonyManager.CALL_STATE_OFFHOOK:

            break;
        }
    }
}

Answer 5

Here is a simple method which can avoid the use of PhonestateListener and other complications.
So here we are receiving the 3 events from android such as RINGING,OFFHOOK and IDLE. And in order to get the all possible state of call,we need to define our own states like RINGING, OFFHOOK, IDLE, FIRST_CALL_RINGING, SECOND_CALL_RINGING. It can handle every states in a phone call.
Please think in a way that we are receiving events from android and we will define our on call states. See the code.

public class CallListening  extends BroadcastReceiver {
    private static final String TAG ="broadcast_intent";
    public static String incoming_number;
    private String current_state,previus_state,event;
    public static Boolean dialog= false;
    private Context context;
    private SharedPreferences sp,sp1;
    private SharedPreferences.Editor spEditor,spEditor1;
    public void onReceive(Context context, Intent intent) {
        //Log.d("intent_log", "Intent" + intent);
        dialog=true;
        this.context = context;
        event = intent.getStringExtra(TelephonyManager.EXTRA_STATE);
        incoming_number = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER);
        Log.d(TAG, "The received event : "+event+", incoming_number : " + incoming_number);
        previus_state = getCallState(context);
        current_state = "IDLE";
        if(incoming_number!=null){
            updateIncomingNumber(incoming_number,context);
        }else {
            incoming_number=getIncomingNumber(context);
        }
        switch (event) {
            case "RINGING":
                Log.d(TAG, "State : Ringing, incoming_number : " + incoming_number);
            if((previus_state.equals("IDLE")) || (previus_state.equals("FIRST_CALL_RINGING"))){
                    current_state ="FIRST_CALL_RINGING";
                }
                if((previus_state.equals("OFFHOOK"))||(previus_state.equals("SECOND_CALL_RINGING"))){
                    current_state = "SECOND_CALL_RINGING";
                }

                break;
            case "OFFHOOK":
                Log.d(TAG, "State : offhook, incoming_number : " + incoming_number);
                if((previus_state.equals("IDLE")) ||(previus_state.equals("FIRST_CALL_RINGING")) || previus_state.equals("OFFHOOK")){
                    current_state = "OFFHOOK";
                }
                if(previus_state.equals("SECOND_CALL_RINGING")){
                    current_state ="OFFHOOK";
                    startDialog(context);
                }
                break;
            case "IDLE":
                Log.d(TAG, "State : idle and  incoming_number : " + incoming_number);
                if((previus_state.equals("OFFHOOK")) || (previus_state.equals("SECOND_CALL_RINGING")) || (previus_state.equals("IDLE"))){
                    current_state="IDLE";
                }
                if(previus_state.equals("FIRST_CALL_RINGING")){
                    current_state = "IDLE";
                    startDialog(context);
                }
                updateIncomingNumber("no_number",context);
                Log.d(TAG,"stored incoming number flushed");
                break;
        }
        if(!current_state.equals(previus_state)){
            Log.d(TAG, "Updating  state from "+previus_state +" to "+current_state);
            updateCallState(current_state,context);

        }
    }
    public void startDialog(Context context) {
        Log.d(TAG,"Starting Dialog box");
        Intent intent1 = new Intent(context, NotifyHangup.class);
        intent1.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent1);

    }
    public void updateCallState(String state,Context context){
        sp = PreferenceManager.getDefaultSharedPreferences(context);
        spEditor = sp.edit();
        spEditor.putString("call_state", state);
        spEditor.commit();
        Log.d(TAG, "state updated");

    }
    public void updateIncomingNumber(String inc_num,Context context){
        sp = PreferenceManager.getDefaultSharedPreferences(context);
        spEditor = sp.edit();
        spEditor.putString("inc_num", inc_num);
        spEditor.commit();
        Log.d(TAG, "incoming number updated");
    }
    public String getCallState(Context context){
        sp1 = PreferenceManager.getDefaultSharedPreferences(context);
        String st =sp1.getString("call_state", "IDLE");
        Log.d(TAG,"get previous state as :"+st);
        return st;
    }
    public String getIncomingNumber(Context context){
        sp1 = PreferenceManager.getDefaultSharedPreferences(context);
        String st =sp1.getString("inc_num", "no_num");
        Log.d(TAG,"get incoming number as :"+st);
        return st;
    }
}

Answer 6

UPDATE: The really awesome code posted by Gabe Sechan no longer works unless you explicitly request the user to grant the necessary permissions. Here is some code that you can place in your main activity to request these permissions:

    if (getApplicationContext().checkSelfPermission(Manifest.permission.READ_PHONE_STATE)
            != PackageManager.PERMISSION_GRANTED) {
        // Permission has not been granted, therefore prompt the user to grant permission
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.READ_PHONE_STATE},
                MY_PERMISSIONS_REQUEST_READ_PHONE_STATE);
    }

    if (getApplicationContext().checkSelfPermission(Manifest.permission.PROCESS_OUTGOING_CALLS)
            != PackageManager.PERMISSION_GRANTED) {
        // Permission has not been granted, therefore prompt the user to grant permission
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.PROCESS_OUTGOING_CALLS},
                MY_PERMISSIONS_REQUEST_PROCESS_OUTGOING_CALLS);
    }

ALSO: As someone mentioned in a comment below Gabe's post, you have to add a little snippet of code, "android:enabled="true", to the receiver in order to detect incoming calls when the app is not currently running in the foreground:

    <!--This part is inside the application-->
    <receiver android:name=".CallReceiver" android:enabled="true">
        <intent-filter>
            <action android:name="android.intent.action.PHONE_STATE" />
        </intent-filter>
        <intent-filter>
            <action android:name="android.intent.action.NEW_OUTGOING_CALL" />
        </intent-filter>
    </receiver>