How to start something when voice call starts?

Question

I have built full voice recorder application.

I would like to start recording when a voice call starts on the phone, how can I detect the Calls state? tried some code and it didn't work for me.

I just need to know hot to start recording when a voice call starts (incoming and outgoing).

Answer 1

Here is an example of what you need.

Declare receiver in AndroidManifest

<receiver android:name=".IncomingCall">   
            <intent-filter>
               <action android:name="android.intent.action.PHONE_STATE" />
            </intent-filter>
    </receiver>

Give read phone state permission in AndroidManifest

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

Create a class IncomingCall with extends BroadcastReceiver class

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.telephony.PhoneStateListener;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.widget.Toast;

/**
 * Created by matheszabi on Aug/20/2017 0020.
 */

public class IncomingCall extends BroadcastReceiver {

    private Context context;

    public void onReceive(Context context, Intent intent) {

        this.context = context;
        try {
            // TELEPHONY MANAGER class object to register one listner
            TelephonyManager tmgr = (TelephonyManager) context
                    .getSystemService(Context.TELEPHONY_SERVICE);

            //Create Listner
            MyPhoneStateListener PhoneListener = new MyPhoneStateListener();

            // Register listener for LISTEN_CALL_STATE
            tmgr.listen(PhoneListener, PhoneStateListener.LISTEN_CALL_STATE);

        } catch (Exception e) {
            Log.e("Phone Receive Error", " " + e);
        }

    }

    private class MyPhoneStateListener extends PhoneStateListener {

        public void onCallStateChanged(int state, String incomingNumber) {

            Log.d("MyPhoneListener",state+"   incoming no:"+incomingNumber);

            if (state == 1) {

                String msg = "New Phone Call Event. Incomming Number : "+incomingNumber;
                int duration = Toast.LENGTH_LONG;
                Toast toast = Toast.makeText(context, msg, duration);
                toast.show();

            }
        }
    }
}

Above Android 6.0 you need to handle a bit different the permissions:

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private static final int MY_REQUEST_CODE = 1234;

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



    @Override
    protected void onResume() {
        super.onResume();

        if (checkSelfPermission(Manifest.permission.READ_PHONE_STATE)
                != PackageManager.PERMISSION_GRANTED) {

            requestPermissions(new String[]{Manifest.permission.READ_PHONE_STATE},
                    MY_REQUEST_CODE);
        }
    }


    public void onRequestPermissionResult(int requestCode, String[] permissions, int[] grantResults) {
        if (requestCode == MY_REQUEST_CODE) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Now user should be able to use camera
                Toast.makeText(this, "I have  access", Toast.LENGTH_SHORT).show();
            } else {
                Toast.makeText(this, "I DON'T have  access", Toast.LENGTH_SHORT).show();
            }


        }
    }
}

You must allow the permissions at the first time run:

Here is the screenshot of the working code: