[Settings] Code refactor

1. Fix comments
2. Split test case

Bug: 147338143
Test: make RunSettingsRoboTests ROBOTEST_FILTER=DataUsageListTest
Change-Id: I017a3ac8a716e69eb4d9c3e30e20363a215563a2

src/com/android/settings/datausage/BillingCyclePreference.java

@@ -96,7 +96,7 @@ public class BillingCyclePreference extends Preference
     }
 
     /**
-     * Implementation of MobileDataEnabledListener.Client
+     * Implementation of {@code MobileDataEnabledListener.Client}
      */
     public void onMobileDataEnabledChange() {
         updateEnabled();

src/com/android/settings/datausage/CellDataPreference.java

@@ -240,7 +240,7 @@ public class CellDataPreference extends CustomDialogPreferenceCompat
             };
 
     /**
-     * Implementation of MobileDataEnabledListener.Client
+     * Implementation of {@code MobileDataEnabledListener.Client}
     */
     @VisibleForTesting
     public void onMobileDataEnabledChange() {

src/com/android/settings/datausage/DataUsageList.java

@@ -201,7 +201,6 @@ public class DataUsageList extends DataUsageBaseFragment
     public void onDestroy() {
         mUidDetailProvider.clearCache();
         mUidDetailProvider = null;
-        mDataStateListener.stop();
 
         super.onDestroy();
     }
@@ -232,7 +231,7 @@ public class DataUsageList extends DataUsageBaseFragment
     }
 
     /**
-     * Implementation of MobileDataEnabledListener.Client
+     * Implementation of {@code MobileDataEnabledListener.Client}
      */
     public void onMobileDataEnabledChange() {
         updatePolicy();

src/com/android/settings/datausage/DataUsageSummary.java

@@ -78,7 +78,7 @@ public class DataUsageSummary extends DataUsageBaseFragment implements DataUsage
         super.onCreate(icicle);
         Context context = getContext();
 
-        // enable ProxySubscriptionMgr with Lifecycle support for all controllers
+        // Enable ProxySubscriptionMgr with Lifecycle support for all controllers
         // live within this fragment
         mProxySubscriptionMgr = ProxySubscriptionManager.getInstance(context);
         mProxySubscriptionMgr.setLifecycle(getLifecycle());

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

@@ -25,12 +25,12 @@ public class MobileDataEnabledListener {
     private Context mContext;
     private Client mClient;
     private int mSubId;
-    /**
+
-     * There're 2 listeners both activated at the same time.
+    // There're 2 listeners both activated at the same time.
-     * For project that access MOBILE_DATA, only first listener is functional.
+    // For project that access MOBILE_DATA, only first listener is functional.
-     * For project that access "MOBILE_DATA + subId", first listener will be stopped when receiving
+    // For project that access "MOBILE_DATA + subId", first listener will be stopped when receiving
-     * any onChange from second listener.
+    // any onChange from second listener.
-     */
+
     private GlobalSettingsChangeListener mListener;
     private GlobalSettingsChangeListener mListenerForSubId;
 

tests/robotests/src/com/android/settings/datausage/DataUsageListTest.java

@@ -93,7 +93,7 @@ public class DataUsageListTest {
     }
 
     @Test
-    public void resumePause_shouldListenUnlistenDataStateChange() {
+    public void resume_shouldListenDataStateChange() {
         ReflectionHelpers.setField(
                 mDataUsageList, "mVisibilityLoggerMixin", mock(VisibilityLoggerMixin.class));
         ReflectionHelpers.setField(
@@ -104,6 +104,17 @@ public class DataUsageListTest {
         verify(mMobileDataEnabledListener).start(anyInt());
 
         mDataUsageList.onPause();
+    }
+
+    @Test
+    public void pause_shouldUnlistenDataStateChange() {
+        ReflectionHelpers.setField(
+                mDataUsageList, "mVisibilityLoggerMixin", mock(VisibilityLoggerMixin.class));
+        ReflectionHelpers.setField(
+                mDataUsageList, "mPreferenceManager", mock(PreferenceManager.class));
+
+        mDataUsageList.onResume();
+        mDataUsageList.onPause();
 
         verify(mMobileDataEnabledListener).stop();
     }