Merge "Add subscriptions list to the multi-network header"
diff --git a/res/xml/network_and_internet_v2.xml b/res/xml/network_and_internet_v2.xml
index 974739d..8e0b426 100644
--- a/res/xml/network_and_internet_v2.xml
+++ b/res/xml/network_and_internet_v2.xml
@@ -18,8 +18,7 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:settings="http://schemas.android.com/apk/res-auto"
     android:key="network_and_internet_screen"
-    android:title="@string/network_dashboard_title"
-    settings:initialExpandedChildrenCount="5">
+    android:title="@string/network_dashboard_title">
 
     <PreferenceCategory
         android:key="multi_network_header"
diff --git a/src/com/android/settings/network/MultiNetworkHeaderController.java b/src/com/android/settings/network/MultiNetworkHeaderController.java
index 1c0fc74..881aaa2 100644
--- a/src/com/android/settings/network/MultiNetworkHeaderController.java
+++ b/src/com/android/settings/network/MultiNetworkHeaderController.java
@@ -19,18 +19,55 @@
 import android.content.Context;
 
 import com.android.settings.core.BasePreferenceController;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceScreen;
 
 // This controls a header at the top of the Network & internet page that only appears when there
 // are two or more active mobile subscriptions. It shows an overview of available network
 // connections with an entry for wifi (if connected) and an entry for each subscription.
-public class MultiNetworkHeaderController extends BasePreferenceController {
+public class MultiNetworkHeaderController extends BasePreferenceController implements
+        SubscriptionsPreferenceController.UpdateListener {
+    public static final String TAG = "MultiNetworkHdrCtrl";
+
+    private SubscriptionsPreferenceController mSubscriptionsController;
+    private PreferenceCategory mPreferenceCategory;
 
     public MultiNetworkHeaderController(Context context, String key) {
-      super(context, key);
+        super(context, key);
+    }
+
+    public void init(Lifecycle lifecycle) {
+        mSubscriptionsController = createSubscriptionsController(lifecycle);
+        // TODO(asargent) - add in a controller for showing wifi status here
+    }
+
+    @VisibleForTesting
+    SubscriptionsPreferenceController createSubscriptionsController(Lifecycle lifecycle) {
+        return new SubscriptionsPreferenceController(mContext, lifecycle, this, mPreferenceKey, 10);
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreferenceCategory = (PreferenceCategory) screen.findPreference(mPreferenceKey);
+        mPreferenceCategory.setVisible(isAvailable());
+        mSubscriptionsController.displayPreference(screen);
     }
 
     @Override
     public int getAvailabilityStatus() {
-        return UNSUPPORTED_ON_DEVICE;
+        if (mSubscriptionsController == null || !mSubscriptionsController.isAvailable()) {
+            return CONDITIONALLY_UNAVAILABLE;
+        } else {
+            return AVAILABLE;
+        }
+    }
+
+    @Override
+    public void onChildrenUpdated() {
+        mPreferenceCategory.setVisible(isAvailable());
     }
 }
diff --git a/src/com/android/settings/network/NetworkDashboardFragment.java b/src/com/android/settings/network/NetworkDashboardFragment.java
index 70481f1..7d94bba 100644
--- a/src/com/android/settings/network/NetworkDashboardFragment.java
+++ b/src/com/android/settings/network/NetworkDashboardFragment.java
@@ -72,6 +72,9 @@
     public void onAttach(Context context) {
         super.onAttach(context);
 
+        if (FeatureFlagUtils.isEnabled(context, FeatureFlags.NETWORK_INTERNET_V2)) {
+            use(MultiNetworkHeaderController.class).init(getSettingsLifecycle());
+        }
         use(AirplaneModePreferenceController.class).setFragment(this);
     }
 
diff --git a/src/com/android/settings/network/SubscriptionUtil.java b/src/com/android/settings/network/SubscriptionUtil.java
index cfe27db..6b14759 100644
--- a/src/com/android/settings/network/SubscriptionUtil.java
+++ b/src/com/android/settings/network/SubscriptionUtil.java
@@ -24,8 +24,20 @@
 import java.util.Iterator;
 import java.util.List;
 
+import androidx.annotation.VisibleForTesting;
+
 public class SubscriptionUtil {
+    private static List<SubscriptionInfo> sResultsForTesting;
+
+    @VisibleForTesting
+    static void setAvailableSubscriptionsForTesting(List<SubscriptionInfo> results) {
+        sResultsForTesting = results;
+    }
+
     public static List<SubscriptionInfo> getAvailableSubscriptions(SubscriptionManager manager) {
+        if (sResultsForTesting != null) {
+            return sResultsForTesting;
+        }
         List<SubscriptionInfo> subscriptions = manager.getAvailableSubscriptionInfoList();
         if (subscriptions == null) {
             subscriptions = new ArrayList<>();
diff --git a/src/com/android/settings/network/SubscriptionsPreferenceController.java b/src/com/android/settings/network/SubscriptionsPreferenceController.java
new file mode 100644
index 0000000..9e55341
--- /dev/null
+++ b/src/com/android/settings/network/SubscriptionsPreferenceController.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.network;
+
+import static androidx.lifecycle.Lifecycle.Event.ON_PAUSE;
+import static androidx.lifecycle.Lifecycle.Event.ON_RESUME;
+
+import android.content.Context;
+import android.telephony.SubscriptionInfo;
+import android.telephony.SubscriptionManager;
+
+import com.android.settings.R;
+import com.android.settingslib.core.AbstractPreferenceController;
+
+import java.util.Map;
+
+import androidx.collection.ArrayMap;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.OnLifecycleEvent;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceGroup;
+import androidx.preference.PreferenceScreen;
+
+/**
+ * This manages a set of Preferences it places into a PreferenceGroup owned by some parent
+ * controller class - one for each available subscription. This controller is only considered
+ * available if there are 2 or more subscriptions.
+ */
+public class SubscriptionsPreferenceController extends AbstractPreferenceController implements
+        LifecycleObserver, SubscriptionsChangeListener.SubscriptionsChangeListenerClient {
+    private static final String TAG = "SubscriptionsPrefCntrlr";
+
+    private UpdateListener mUpdateListener;
+    private String mPreferenceGroupKey;
+    private PreferenceGroup mPreferenceGroup;
+    private SubscriptionManager mManager;
+    private SubscriptionsChangeListener mSubscriptionsListener;
+
+    // Map of subscription id to Preference
+    private Map<Integer, Preference> mSubscriptionPreferences;
+    private int mStartOrder;
+
+    /**
+     * This interface lets a parent of this class know that some change happened - this could
+     * either be because overall availability changed, or because we've added/removed/updated some
+     * preferences.
+     */
+    public interface UpdateListener {
+        void onChildrenUpdated();
+    }
+
+    /**
+     * @param context            the context for the UI where we're placing these preferences
+     * @param lifecycle          for listening to lifecycle events for the UI
+     * @param updateListener     called to let our parent controller know that our availability has
+     *                           changed, or that one or more of the preferences we've placed in the
+     *                           PreferenceGroup has changed
+     * @param preferenceGroupKey the key used to lookup the PreferenceGroup where Preferences will
+     *                           be placed
+     * @param startOrder         the order that should be given to the first Preference placed into
+     *                           the PreferenceGroup; the second will use startOrder+1, third will
+     *                           use startOrder+2, etc. - this is useful for when the parent wants
+     *                           to have other preferences in the same PreferenceGroup and wants
+     *                           a specific ordering relative to this controller's prefs.
+     */
+    public SubscriptionsPreferenceController(Context context, Lifecycle lifecycle,
+            UpdateListener updateListener, String preferenceGroupKey, int startOrder) {
+        super(context);
+        mUpdateListener = updateListener;
+        mPreferenceGroupKey = preferenceGroupKey;
+        mStartOrder = startOrder;
+        mManager = context.getSystemService(SubscriptionManager.class);
+        mSubscriptionPreferences = new ArrayMap<>();
+        mSubscriptionsListener = new SubscriptionsChangeListener(context, this);
+        lifecycle.addObserver(this);
+    }
+
+    @OnLifecycleEvent(ON_RESUME)
+    public void onResume() {
+        mSubscriptionsListener.start();
+        update();
+    }
+
+    @OnLifecycleEvent(ON_PAUSE)
+    public void onPause() {
+        mSubscriptionsListener.stop();
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        mPreferenceGroup = (PreferenceGroup) screen.findPreference(mPreferenceGroupKey);
+        update();
+    }
+
+    private void update() {
+        if (mPreferenceGroup == null) {
+            return;
+        }
+
+        if (mSubscriptionsListener.isAirplaneModeOn()) {
+            for (Preference pref : mSubscriptionPreferences.values()) {
+                mPreferenceGroup.removePreference(pref);
+            }
+            mSubscriptionPreferences.clear();
+            mUpdateListener.onChildrenUpdated();
+            return;
+        }
+
+        final Map<Integer, Preference> existingPrefs = mSubscriptionPreferences;
+        mSubscriptionPreferences = new ArrayMap<>();
+
+        int order = mStartOrder;
+        for (SubscriptionInfo info :  SubscriptionUtil.getAvailableSubscriptions(mManager) ) {
+            final int subId = info.getSubscriptionId();
+            Preference pref = existingPrefs.remove(subId);
+            if (pref == null) {
+                pref = new Preference(mPreferenceGroup.getContext());
+                mPreferenceGroup.addPreference(pref);
+            }
+            pref.setTitle(info.getDisplayName());
+            pref.setIcon(R.drawable.ic_network_cell);
+            pref.setOrder(order++);
+
+            // TODO(asargent) - set summary here to indicate default for calls/sms and data
+
+            pref.setOnPreferenceClickListener(clickedPref -> {
+                // TODO(asargent) - make this start MobileNetworkActivity once we've
+                // added support for it to take a subscription id
+                return true;
+            });
+
+            mSubscriptionPreferences.put(subId, pref);
+        }
+
+        // Remove any old preferences that no longer map to a subscription.
+        for (Preference pref : existingPrefs.values()) {
+            mPreferenceGroup.removePreference(pref);
+        }
+        mUpdateListener.onChildrenUpdated();
+    }
+
+    /**
+     *
+     * @return true if there are at least 2 available subscriptions.
+     */
+    @Override
+    public boolean isAvailable() {
+        if (mSubscriptionsListener.isAirplaneModeOn()) {
+            return false;
+        }
+        return SubscriptionUtil.getAvailableSubscriptions(mManager).size() >= 2;
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return null;
+    }
+
+    @Override
+    public void onAirplaneModeChanged(boolean airplaneModeEnabled) {
+        update();
+    }
+
+    @Override
+    public void onSubscriptionsChanged() {
+        update();
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/network/MultiNetworkHeaderControllerTest.java b/tests/robotests/src/com/android/settings/network/MultiNetworkHeaderControllerTest.java
new file mode 100644
index 0000000..fbd7867
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/network/MultiNetworkHeaderControllerTest.java
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.network;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.telephony.SubscriptionManager;
+
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import java.util.List;
+
+import androidx.lifecycle.LifecycleOwner;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceScreen;
+
+@RunWith(RobolectricTestRunner.class)
+public class MultiNetworkHeaderControllerTest {
+    private static final String KEY_HEADER = "multi_network_header";
+
+    @Mock
+    private PreferenceScreen mPreferenceScreen;
+    @Mock
+    private PreferenceCategory mPreferenceCategory;
+    @Mock
+    private SubscriptionsPreferenceController mSubscriptionsController;
+    @Mock
+    private SubscriptionManager mSubscriptionManager;
+
+    private Context mContext;
+    private LifecycleOwner mLifecycleOwner;
+    private Lifecycle mLifecycle;
+    private MultiNetworkHeaderController mHeaderController;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
+        mLifecycleOwner = () -> mLifecycle;
+        mLifecycle = new Lifecycle(mLifecycleOwner);
+        when(mContext.getSystemService(SubscriptionManager.class)).thenReturn(mSubscriptionManager);
+        when(mPreferenceScreen.findPreference(eq(KEY_HEADER))).thenReturn(mPreferenceCategory);
+
+        mHeaderController = spy(new MultiNetworkHeaderController(mContext, KEY_HEADER));
+        doReturn(mSubscriptionsController).when(mHeaderController).createSubscriptionsController(
+                mLifecycle);
+    }
+
+    @Test
+    public void isAvailable_beforeInitIsCalled_notAvailable() {
+        assertThat(mHeaderController.isAvailable()).isFalse();
+    }
+
+    // When calling displayPreference, the header itself should only be visible if the
+    // subscriptions controller says it is available. This is a helper for test cases of this logic.
+    private void displayPreferenceTest(boolean subscriptionsAvailable,
+            boolean setVisibleExpectedValue) {
+        when(mSubscriptionsController.isAvailable()).thenReturn(subscriptionsAvailable);
+
+        mHeaderController.init(mLifecycle);
+        mHeaderController.displayPreference(mPreferenceScreen);
+        verify(mPreferenceCategory, never()).setVisible(eq(!setVisibleExpectedValue));
+        verify(mPreferenceCategory, atLeastOnce()).setVisible(eq(setVisibleExpectedValue));
+    }
+
+    @Test
+    public void displayPreference_subscriptionsNotAvailable_categoryIsNotVisible() {
+        displayPreferenceTest(false, false);
+    }
+
+    @Test
+    public void displayPreference_subscriptionsAvailable_categoryIsVisible() {
+        displayPreferenceTest(true, true);
+    }
+
+    @Test
+    public void onChildUpdated_subscriptionsBecameAvailable_categoryIsVisible() {
+        when(mSubscriptionsController.isAvailable()).thenReturn(false);
+        mHeaderController.init(mLifecycle);
+        mHeaderController.displayPreference(mPreferenceScreen);
+
+        when(mSubscriptionsController.isAvailable()).thenReturn(true);
+        mHeaderController.onChildrenUpdated();
+        ArgumentCaptor<Boolean> captor = ArgumentCaptor.forClass(Boolean.class);
+
+        verify(mPreferenceCategory, atLeastOnce()).setVisible(captor.capture());
+        List<Boolean> values = captor.getAllValues();
+        assertThat(values.get(values.size()-1)).isEqualTo(Boolean.TRUE);
+    }
+
+    @Test
+    public void onChildUpdated_subscriptionsBecameUnavailable_categoryIsNotVisible() {
+        when(mSubscriptionsController.isAvailable()).thenReturn(true);
+        mHeaderController.init(mLifecycle);
+        mHeaderController.displayPreference(mPreferenceScreen);
+
+        when(mSubscriptionsController.isAvailable()).thenReturn(false);
+        mHeaderController.onChildrenUpdated();
+        ArgumentCaptor<Boolean> captor = ArgumentCaptor.forClass(Boolean.class);
+
+        verify(mPreferenceCategory, atLeastOnce()).setVisible(captor.capture());
+        List<Boolean> values = captor.getAllValues();
+        assertThat(values.get(values.size()-1)).isEqualTo(Boolean.FALSE);
+    }
+}
diff --git a/tests/robotests/src/com/android/settings/network/SubscriptionsPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/network/SubscriptionsPreferenceControllerTest.java
new file mode 100644
index 0000000..016a885
--- /dev/null
+++ b/tests/robotests/src/com/android/settings/network/SubscriptionsPreferenceControllerTest.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.network;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+import android.provider.Settings;
+import android.telephony.SubscriptionInfo;
+import android.telephony.SubscriptionManager;
+
+import com.android.settingslib.core.lifecycle.Lifecycle;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import androidx.lifecycle.LifecycleOwner;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceScreen;
+
+@RunWith(RobolectricTestRunner.class)
+public class SubscriptionsPreferenceControllerTest {
+    private static final String KEY = "preference_group";
+
+    @Mock
+    private PreferenceScreen mScreen;
+    @Mock
+    private PreferenceCategory mPreferenceCategory;
+    @Mock
+    private SubscriptionManager mSubscriptionManager;
+
+    private Context mContext;
+    private LifecycleOwner mLifecycleOwner;
+    private Lifecycle mLifecycle;
+    private SubscriptionsPreferenceController mController;
+    private int mOnChildUpdatedCount;
+    private SubscriptionsPreferenceController.UpdateListener mUpdateListener;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(RuntimeEnvironment.application);
+        mLifecycleOwner = () -> mLifecycle;
+        mLifecycle = new Lifecycle(mLifecycleOwner);
+        when(mContext.getSystemService(SubscriptionManager.class)).thenReturn(mSubscriptionManager);
+        when(mScreen.findPreference(eq(KEY))).thenReturn(mPreferenceCategory);
+        when(mPreferenceCategory.getContext()).thenReturn(mContext);
+        mOnChildUpdatedCount = 0;
+        mUpdateListener = () -> mOnChildUpdatedCount++;
+
+        mController = new SubscriptionsPreferenceController(mContext, mLifecycle, mUpdateListener,
+                KEY, 5);
+    }
+
+    @Test
+    public void isAvailable_oneSubscription_availableFalse() {
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(
+                Arrays.asList(mock(SubscriptionInfo.class)));
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
+    public void isAvailable_twoSubscriptions_availableTrue() {
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(
+                Arrays.asList(mock(SubscriptionInfo.class), mock(SubscriptionInfo.class)));
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void isAvailable_fiveSubscriptions_availableTrue() {
+        final ArrayList<SubscriptionInfo> subs = new ArrayList<>();
+        for (int i = 0; i < 5; i++) {
+            subs.add(mock(SubscriptionInfo.class));
+        }
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(subs);
+        assertThat(mController.isAvailable()).isTrue();
+    }
+
+    @Test
+    public void isAvailable_airplaneModeOn_availableFalse() {
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(
+                Arrays.asList(mock(SubscriptionInfo.class), mock(SubscriptionInfo.class)));
+        assertThat(mController.isAvailable()).isTrue();
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.AIRPLANE_MODE_ON, 1);
+        assertThat(mController.isAvailable()).isFalse();
+    }
+
+    @Test
+    public void onAirplaneModeChanged_airplaneModeTurnedOn_eventFired() {
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(
+                Arrays.asList(mock(SubscriptionInfo.class), mock(SubscriptionInfo.class)));
+        mController.onResume();
+        mController.displayPreference(mScreen);
+        assertThat(mController.isAvailable()).isTrue();
+
+        final int updateCountBeforeModeChange = mOnChildUpdatedCount;
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.AIRPLANE_MODE_ON, 1);
+        mController.onAirplaneModeChanged(true);
+        assertThat(mController.isAvailable()).isFalse();
+        assertThat(mOnChildUpdatedCount).isEqualTo(updateCountBeforeModeChange + 1);
+    }
+
+    @Test
+    public void onAirplaneModeChanged_airplaneModeTurnedOff_eventFired() {
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.AIRPLANE_MODE_ON, 1);
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(
+                Arrays.asList(mock(SubscriptionInfo.class), mock(SubscriptionInfo.class)));
+        mController.onResume();
+        mController.displayPreference(mScreen);
+        assertThat(mController.isAvailable()).isFalse();
+
+        final int updateCountBeforeModeChange = mOnChildUpdatedCount;
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.AIRPLANE_MODE_ON, 0);
+        mController.onAirplaneModeChanged(false);
+        assertThat(mController.isAvailable()).isTrue();
+        assertThat(mOnChildUpdatedCount).isEqualTo(updateCountBeforeModeChange + 1);
+    }
+
+    @Test
+    public void onSubscriptionsChanged_countBecameTwo_eventFired() {
+        final SubscriptionInfo sub1 = mock(SubscriptionInfo.class);
+        final SubscriptionInfo sub2 = mock(SubscriptionInfo.class);
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1));
+        mController.onResume();
+        mController.displayPreference(mScreen);
+        assertThat(mController.isAvailable()).isFalse();
+
+        final int updateCountBeforeSubscriptionChange = mOnChildUpdatedCount;
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1, sub2));
+        mController.onSubscriptionsChanged();
+        assertThat(mController.isAvailable()).isTrue();
+        assertThat(mOnChildUpdatedCount).isEqualTo(updateCountBeforeSubscriptionChange + 1);
+    }
+
+    @Test
+    public void onSubscriptionsChanged_countBecameOne_eventFired() {
+        final SubscriptionInfo sub1 = mock(SubscriptionInfo.class);
+        final SubscriptionInfo sub2 = mock(SubscriptionInfo.class);
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1, sub2));
+        mController.onResume();
+        mController.displayPreference(mScreen);
+        assertThat(mController.isAvailable()).isTrue();
+
+        final int updateCountBeforeSubscriptionChange = mOnChildUpdatedCount;
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1));
+        mController.onSubscriptionsChanged();
+        assertThat(mController.isAvailable()).isFalse();
+        assertThat(mOnChildUpdatedCount).isEqualTo(updateCountBeforeSubscriptionChange + 1);
+    }
+
+
+    @Test
+    public void onSubscriptionsChanged_subscriptionReplaced_preferencesChanged() {
+        final SubscriptionInfo sub1 = mock(SubscriptionInfo.class);
+        final SubscriptionInfo sub2 = mock(SubscriptionInfo.class);
+        final SubscriptionInfo sub3 = mock(SubscriptionInfo.class);
+        when(sub1.getDisplayName()).thenReturn("sub1");
+        when(sub2.getDisplayName()).thenReturn("sub2");
+        when(sub3.getDisplayName()).thenReturn("sub3");
+        when(sub1.getSubscriptionId()).thenReturn(1);
+        when(sub2.getSubscriptionId()).thenReturn(2);
+        when(sub3.getSubscriptionId()).thenReturn(3);
+
+        // Start out with only sub1 and sub2.
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1, sub2));
+        mController.onResume();
+        mController.displayPreference(mScreen);
+        final ArgumentCaptor<Preference> captor = ArgumentCaptor.forClass(Preference.class);
+        verify(mPreferenceCategory, times(2)).addPreference(captor.capture());
+        assertThat(captor.getAllValues().size()).isEqualTo(2);
+        assertThat(captor.getAllValues().get(0).getTitle()).isEqualTo("sub1");
+        assertThat(captor.getAllValues().get(1).getTitle()).isEqualTo("sub2");
+
+        // Now replace sub2 with sub3, and make sure the old preference was removed and the new
+        // preference was added.
+        final int updateCountBeforeSubscriptionChange = mOnChildUpdatedCount;
+        SubscriptionUtil.setAvailableSubscriptionsForTesting(Arrays.asList(sub1, sub3));
+        mController.onSubscriptionsChanged();
+        assertThat(mController.isAvailable()).isTrue();
+        assertThat(mOnChildUpdatedCount).isEqualTo(updateCountBeforeSubscriptionChange + 1);
+
+        verify(mPreferenceCategory).removePreference(captor.capture());
+        assertThat(captor.getValue().getTitle()).isEqualTo("sub2");
+        verify(mPreferenceCategory, times(3)).addPreference(captor.capture());
+        assertThat(captor.getValue().getTitle()).isEqualTo("sub3");
+    }
+}