Merge "Helper function to return the unique name for subscription info"

src/com/android/settings/network/SubscriptionUtil.java

@@ -324,6 +324,23 @@ public class SubscriptionUtil {
         return displayNames.getOrDefault(subscriptionId, "");
     }
 
+    /**
+     * Return the display name for a subscription, which is guaranteed to be unique.
+     * The logic to create this name has the following order of operations:
+     * 1) If the original display name is not unique, the last four digits of the phone number
+     *    will be appended.
+     * 2) If the phone number is not visible or the last four digits are shared with another
+     *    subscription, the subscription id will be appended to the original display name.
+     * More details can be found at go/unique-sub-display-names.
+     *
+     * @return map of active subscription ids to diaplay names.
+     */
+    @VisibleForTesting
+    public static CharSequence getUniqueSubscriptionDisplayName(
+            SubscriptionInfo info, Context context) {
+        return getUniqueSubscriptionDisplayName(info.getSubscriptionId(), context);
+    }
+
     public static String getDisplayName(SubscriptionInfo info) {
         final CharSequence name = info.getDisplayName();
         if (name != null) {

tests/unit/src/com/android/settings/network/SubscriptionUtilTest.java

@@ -360,6 +360,26 @@ public class SubscriptionUtilTest {
         assertTrue(TextUtils.isEmpty(name));
     }
 
+    @Test
+    public void getUniqueDisplayName_fullSubscriptionInfo_correctNameReturned() {
+        // Each subscription's default display name is unique.
+        final SubscriptionInfo info1 = mock(SubscriptionInfo.class);
+        when(info1.getSubscriptionId()).thenReturn(SUBID_1);
+        when(info1.getDisplayName()).thenReturn(CARRIER_1);
+        when(mSubMgr.getActiveSubscriptionInfoList()).thenReturn(
+                Arrays.asList(info1));
+
+        TelephonyManager sub1Telmgr = mock(TelephonyManager.class);
+        when(sub1Telmgr.getLine1Number()).thenReturn("1112223333");
+        when(mTelMgr.createForSubscriptionId(SUBID_1)).thenReturn(sub1Telmgr);
+
+        final CharSequence name =
+                SubscriptionUtil.getUniqueSubscriptionDisplayName(info1, mContext);
+
+        assertThat(name).isNotNull();
+        assertEquals(CARRIER_1, name);
+    }
+
     @Test
     public void isInactiveInsertedPSim_nullSubInfo_doesNotCrash() {
         assertThat(SubscriptionUtil.isInactiveInsertedPSim(null)).isFalse();