Merge changes from topic 'call-session-may'

* changes:
  Add callSessionMayHandover API to ImsCallSession.
  IMS: Support for Possible Call Session Handover

telephony/java/android/telephony/ims/stub/ImsCallSessionListenerImplBase.java

@@ -195,6 +195,23 @@ public class ImsCallSessionListenerImplBase extends IImsCallSessionListener.Stub
         // no-op
     }
 
+    /**
+     * Notifies of a case where a {@link com.android.ims.internal.ImsCallSession} may potentially
+     * handover from one radio technology to another.
+     * @param session
+     * @param srcAccessTech The source radio access technology; one of the access technology
+     *                      constants defined in {@link android.telephony.ServiceState}.  For
+     *                      example {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_LTE}.
+     * @param targetAccessTech The target radio access technology; one of the access technology
+     *                      constants defined in {@link android.telephony.ServiceState}.  For
+     *                      example {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_LTE}.
+     */
+    @Override
+    public void callSessionMayHandover(IImsCallSession session, int srcAccessTech,
+            int targetAccessTech) {
+        // no-op
+    }
+
     /**
      * Notifies of handover information for this call
      */

telephony/java/com/android/ims/internal/IImsCallSessionListener.aidl

@@ -106,6 +106,8 @@ oneway interface IImsCallSessionListener {
             in int srcAccessTech, in int targetAccessTech, in ImsReasonInfo reasonInfo);
     void callSessionHandoverFailed(in IImsCallSession session,
             in int srcAccessTech, in int targetAccessTech, in ImsReasonInfo reasonInfo);
+    void callSessionMayHandover(in IImsCallSession session,
+            in int srcAccessTech, in int targetAccessTech);
 
     /**
      * Notifies the TTY mode change by remote party.

telephony/java/com/android/ims/internal/ImsCallSession.java

@@ -344,6 +344,24 @@ public class ImsCallSession {
             // no-op
         }
 
+        /**
+         * Called when an {@link ImsCallSession} may handover from one radio technology to another.
+         * For example, the session may handover from WIFI to LTE if conditions are right.
+         * <p>
+         * If handover is attempted,
+         * {@link #callSessionHandover(ImsCallSession, int, int, ImsReasonInfo)} or
+         * {@link #callSessionHandoverFailed(ImsCallSession, int, int, ImsReasonInfo)} will be
+         * called to indicate the success or failure of the handover.
+         *
+         * @param session IMS session object
+         * @param srcAccessTech original access technology
+         * @param targetAccessTech new access technology
+         */
+        public void callSessionMayHandover(ImsCallSession session, int srcAccessTech,
+                int targetAccessTech) {
+            // no-op
+        }
+
         /**
          * Called when session access technology changes
          *
@@ -1280,6 +1298,28 @@ public class ImsCallSession {
             }
         }
 
+        /**
+         * Notifies of a case where a {@link com.android.ims.internal.ImsCallSession} may
+         * potentially handover from one radio technology to another.
+         * @param session
+         * @param srcAccessTech The source radio access technology; one of the access technology
+         *                      constants defined in {@link android.telephony.ServiceState}.  For
+         *                      example
+         *                      {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_LTE}.
+         * @param targetAccessTech The target radio access technology; one of the access technology
+         *                      constants defined in {@link android.telephony.ServiceState}.  For
+         *                      example
+         *                      {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_LTE}.
+         */
+        @Override
+        public void callSessionMayHandover(IImsCallSession session,
+                int srcAccessTech, int targetAccessTech) {
+            if (mListener != null) {
+                mListener.callSessionMayHandover(ImsCallSession.this, srcAccessTech,
+                        targetAccessTech);
+            }
+        }
+
         /**
          * Notifies of handover information for this call
          */