Add a new phone state ANSWERING.

The state ANSWERING is set when we answer an incoming sip call, i.e.
sending a 'OK' response to the peer. The state will be set to ACTIVE
once the 'ACK' from peer is received.

Change-Id: I84ee3cc68222eb34e032896ce23f7431d4ad774a

telephony/java/com/android/internal/telephony/CallManager.java

@@ -197,10 +197,12 @@ public final class CallManager {
         Phone.State s = Phone.State.IDLE;
 
         for (Phone phone : mPhones) {
-            if (phone.getState() == Phone.State.RINGING) {
-                return Phone.State.RINGING;
+            if (phone.getState() == Phone.State.ANSWERING) {
+                return Phone.State.ANSWERING;
+            } else if (phone.getState() == Phone.State.RINGING) {
+                s = Phone.State.RINGING;
             } else if (phone.getState() == Phone.State.OFFHOOK) {
-                s = Phone.State.OFFHOOK;
+                if (s == Phone.State.IDLE) s = Phone.State.OFFHOOK;
             }
         }
         return s;
@@ -289,6 +291,18 @@ public final class CallManager {
         return getFirstActiveRingingCall().getPhone();
     }
 
+    /**
+     * @return the first answering call
+     */
+    public Call getFirstAnsweringCall() {
+        for (Phone phone : mPhones) {
+            if (phone.getState() == Phone.State.ANSWERING) {
+                return phone.getForegroundCall();
+            }
+        }
+        return null;
+    }
+
     /**
      * unregister phone from CallManager
      * @param phone

telephony/java/com/android/internal/telephony/Phone.java

@@ -55,10 +55,12 @@ public interface Phone {
      * <li>OFFHOOK = The phone is off hook. At least one call
      * exists that is dialing, active or holding and no calls are
      * ringing or waiting.</li>
+     * <li>ANSWERING = The incoming call is picked up but the
+     *  call is not established yet.</li>
      * </ul>
      */
     enum State {
-        IDLE, RINGING, OFFHOOK;
+        IDLE, RINGING, OFFHOOK, ANSWERING;
     };
 
     /**

telephony/java/com/android/internal/telephony/sip/SipPhone.java

@@ -158,6 +158,7 @@ public class SipPhone extends SipPhoneBase {
             } else {
                 throw new CallStateException("phone not ringing");
             }
+            updatePhoneState();
         }
     }
 

telephony/java/com/android/internal/telephony/sip/SipPhoneBase.java

@@ -538,6 +538,8 @@ abstract class SipPhoneBase extends PhoneBase {
 
         if (getRingingCall().isRinging()) {
             state = State.RINGING;
+        } else if (getForegroundCall().isRinging()) {
+            state = State.ANSWERING;
         } else if (getForegroundCall().isIdle()
                 && getBackgroundCall().isIdle()) {
             state = State.IDLE;