[Settings] enhancing data saver config control

Enhancing the control of R.bool.config_show_data_saver when false, which including:
1. Initial presentation is invisible
2. Leaving UI when triggered
3. Avoid from getting searched
4. Robolectric test case support

Bug: 243877672
Test: test cases and local testing
Change-Id: I909522c0244ebb012a27d6aff34120a4f90128c6

res/xml/network_provider_internet.xml

@@ -99,6 +99,7 @@
         android:title="@string/data_saver_title"
         android:icon="@drawable/ic_settings_data_usage"
         android:order="10"
+        settings:isPreferenceVisible="@bool/config_show_data_saver"
         android:fragment="com.android.settings.datausage.DataSaverSummary"/>
 
     <com.android.settings.vpn2.VpnInfoPreference

res/xml/special_access.xml

@@ -103,6 +103,7 @@
         android:key="data_saver"
         android:title="@string/unrestricted_data_saver"
         android:fragment="com.android.settings.datausage.UnrestrictedDataAccess"
+        settings:isPreferenceVisible="@bool/config_show_data_saver"
         settings:controller="com.android.settings.applications.specialaccess.DataSaverController" />
 
     <Preference

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

@@ -67,9 +67,18 @@ public class DataSaverSummary extends SettingsPreferenceFragment
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);
 
+        if (!isDataSaverVisible(getContext())) {
+            finishFragment();
+            return;
+        }
+
         addPreferencesFromResource(R.xml.data_saver);
         mUnrestrictedAccess = findPreference(KEY_UNRESTRICTED_ACCESS);
+        mApplicationsState = ApplicationsState.getInstance(
+                (Application) getContext().getApplicationContext());
         mDataSaverBackend = new DataSaverBackend(getContext());
+        mDataUsageBridge = new AppStateDataUsageBridge(mApplicationsState, this, mDataSaverBackend);
+        mSession = mApplicationsState.newSession(this, getSettingsLifecycle());
     }
 
     @Override
@@ -202,12 +211,18 @@ public class DataSaverSummary extends SettingsPreferenceFragment
                 R.plurals.data_saver_unrestricted_summary, count, count));
     }
 
+    public static boolean isDataSaverVisible(Context context) {
+        return context.getResources()
+            .getBoolean(R.bool.config_show_data_saver);
+    }
+
     public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider(R.xml.data_saver) {
 
                 @Override
                 protected boolean isPageSearchEnabled(Context context) {
-                    return DataUsageUtils.hasMobileData(context)
+                    return isDataSaverVisible(context)
+                            && DataUsageUtils.hasMobileData(context)
                             && DataUsageUtils.getDefaultSubscriptionId(context)
                             != SubscriptionManager.INVALID_SUBSCRIPTION_ID;
                 }

tests/robotests/src/com/android/settings/applications/specialaccess/DataSaverControllerTest.java

@@ -18,9 +18,13 @@ package com.android.settings.applications.specialaccess;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.Mockito.when;
 import static org.mockito.Mockito.spy;
 
 import android.content.Context;
+import android.content.res.Resources;
+
+import com.android.settings.R;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -34,23 +38,35 @@ import org.robolectric.annotation.Config;
 public class DataSaverControllerTest {
 
     private Context mContext;
+    private Resources mResources;
     private DataSaverController mController;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
         mContext = spy(RuntimeEnvironment.application.getApplicationContext());
+
+        mResources = spy(mContext.getResources());
+        when(mContext.getResources()).thenReturn(mResources);
+
         mController = new DataSaverController(mContext, "key");
     }
 
     @Test
     public void testDataSaver_byDefault_shouldBeShown() {
+        when(mResources.getBoolean(R.bool.config_show_data_saver)).thenReturn(true);
         assertThat(mController.isAvailable()).isTrue();
     }
 
     @Test
     @Config(qualifiers = "mcc999")
+    public void testDataSaver_ifDisabledByCarrier_shouldNotBeShown() {
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
     public void testDataSaver_ifDisabled_shouldNotBeShown() {
+        when(mResources.getBoolean(R.bool.config_show_data_saver)).thenReturn(false);
         assertThat(mController.isAvailable()).isFalse();
     }
 }