Question

Is it possible to utilize the users phone through their cell provider, and track the length of a phone call?

So the user presses a button in the app “Call Now”. A call begins to a pre-determined number. We record the start time. When the call ends, we calculate how many minutes were used.

Possible?

Answer 1

To calculate time talked for both incoming , outgoing calls use the following broadcast receiver :

public class CallDurationReceiver extends BroadcastReceiver {

    static boolean flag = false;
    static long start_time, end_time;

    @Override
    public void onReceive(Context arg0, Intent intent) {
        String action = intent.getAction();
        if (action.equalsIgnoreCase("android.intent.action.PHONE_STATE")) {
            if (intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(
            TelephonyManager.EXTRA_STATE_RINGING)) {
                start_time = System.currentTimeMillis();
            }
            if (intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(
            TelephonyManager.EXTRA_STATE_IDLE)) {
                end_time = System.currentTimeMillis();
                //Total time talked =
                long total_time = end_time - start_time;
                //Store total_time somewhere or pass it to an Activity using intent
            }
        }
    }

Register your receiver in your manifest file like this:

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

Also add the uses permission:

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