Improve comment on EXTRA_CALL_RAT_TYPE.

Adding comments to EXTRA_CALL_RAT_TYPE to make it clear what it is used
for, and what values are expected.

Bug: 20144385
Change-Id: I248aca61abc8a57d7aeef650e48cc498e41c859b

1 files changed, 14 insertions, 0 deletions

diff --git a/telephony/java/com/android/ims/ImsCallProfile.java b/telephony/java/com/android/ims/ImsCallProfile.java
index 861a379..5f84e0c 100644
--- a/telephony/java/com/android/ims/ImsCallProfile.java
+++ b/telephony/java/com/android/ims/ImsCallProfile.java
@@ -188,6 +188,20 @@ public class ImsCallProfile implements Parcelable {
     public static final String EXTRA_CODEC = "Codec";
     public static final String EXTRA_DISPLAY_TEXT = "DisplayText";
     public static final String EXTRA_ADDITIONAL_CALL_INFO = "AdditionalCallInfo";
+
+    /**
+     * Extra key which the RIL can use to indicate the radio technology used for a call.
+     * Valid values are:
+     * {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_LTE},
+     * {@link android.telephony.ServiceState#RIL_RADIO_TECHNOLOGY_IWLAN}, and the other defined
+     * {@code RIL_RADIO_TECHNOLOGY_*} constants.
+     * Note: Despite the fact the {@link android.telephony.ServiceState} values are integer
+     * constants, the values passed for the {@link #EXTRA_CALL_RAT_TYPE} should be strings (e.g.
+     * "14" vs (int) 14).
+     * Note: This is used by {@link com.android.internal.telephony.imsphone.ImsPhoneConnection#
+     *      updateWifiStateFromExtras(Bundle)} to determine whether to set the
+     * {@link android.telecom.Connection#CAPABILITY_WIFI} capability on a connection.
+     */
     public static final String EXTRA_CALL_RAT_TYPE = "CallRadioTech";
 
     public int mServiceType;