How can I detect when a call is answered? [duplicate]

Question

Once ACTION_NEW_OUTGOING_CALL has been broadcasted, I need to capture the following event of the other party answer. Could you advice on how to achieve that please? I know it is possible as the Android dialer app changes the green Android icon to the person's photo exactly when they pick up.

UPDATED: I've had a look at the source of the app on Android handling the outgoing calls. I noticed the following method in ContactsUtils:

/**
 * Kick off an intent to initiate a call.
 */

 public static void initiateCall(Context context, CharSequence
 phoneNumber) {
     Intent intent = new Intent(Intent.ACTION_CALL_PRIVILEGED,
             Uri.fromParts("tel", phoneNumber.toString(), null));
     context.startActivity(intent); }

I guess my answer is in the activity listening for Intent.ACTION_CALL_PRIVILEGED. So to rephrase my question: Does anyone know which activity handles Intent.ACTION_CALL_PRIVILEGED?

Answer 1

I don't think there's such API and also there's no API for sending DTMFs due to the same reason that you can't tell when the call is being connected.

Answer 2

It does not necessarily needs to be possible to capture this as an outside app. The green android icon is a part of the application that controls the call, so it does not need a broadcast to change the icon.