Add an on/off switch to the top of mobile network details page

When a device is in DSDS mode and has two mobile network subscriptions,
a user may want to completely disable one of those subscriptions. This
implements the UI for this, calling into some recently added APIs in the
SubscriptionManager class.

Bug: 122670283
Test: make RunSettingsRoboTests
Change-Id: I40fd3e777ce3542004e4761406b24196505b97d8

src/com/android/settings/network/telephony/MobileNetworkSettings.java

@@ -132,6 +132,7 @@ public class MobileNetworkSettings extends RestrictedDashboardFragment {
         if (FeatureFlagPersistent.isEnabled(getContext(), FeatureFlags.NETWORK_INTERNET_V2)) {
           use(CallsDefaultSubscriptionController.class).init(getLifecycle());
           use(SmsDefaultSubscriptionController.class).init(getLifecycle());
+          use(MobileNetworkSwitchController.class).init(getLifecycle(), mSubId);
         }
         use(MobileDataPreferenceController.class).init(getFragmentManager(), mSubId);
         use(RoamingPreferenceController.class).init(getFragmentManager(), mSubId);

src/com/android/settings/network/telephony/MobileNetworkSwitchController.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2019 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.telephony;
+
+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.settings.core.BasePreferenceController;
+import com.android.settings.core.FeatureFlags;
+import com.android.settings.development.featureflags.FeatureFlagPersistent;
+import com.android.settings.network.SubscriptionUtil;
+import com.android.settings.network.SubscriptionsChangeListener;
+import com.android.settings.widget.SwitchBar;
+import com.android.settingslib.widget.LayoutPreference;
+
+import java.util.List;
+
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.OnLifecycleEvent;
+import androidx.preference.PreferenceScreen;
+
+/** This controls a switch to allow enabling/disabling a mobile network */
+public class MobileNetworkSwitchController extends BasePreferenceController implements
+        SubscriptionsChangeListener.SubscriptionsChangeListenerClient, LifecycleObserver {
+    private static final String TAG = "MobileNetworkSwitchCtrl";
+    private SwitchBar mSwitchBar;
+    private int mSubId;
+    private SubscriptionsChangeListener mChangeListener;
+    private SubscriptionManager mSubscriptionManager;
+
+    public MobileNetworkSwitchController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+        mSubId = SubscriptionManager.INVALID_SUBSCRIPTION_ID;
+        mSubscriptionManager = mContext.getSystemService(SubscriptionManager.class);
+        mChangeListener = new SubscriptionsChangeListener(context, this);
+    }
+
+    public void init(Lifecycle lifecycle, int subId) {
+        lifecycle.addObserver(this);
+        mSubId = subId;
+    }
+
+    @OnLifecycleEvent(ON_RESUME)
+    public void onResume() {
+        mChangeListener.start();
+        update();
+    }
+
+    @OnLifecycleEvent(ON_PAUSE)
+    public void onPause() {
+        mChangeListener.stop();
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        final LayoutPreference pref = screen.findPreference(mPreferenceKey);
+        mSwitchBar = pref.findViewById(R.id.switch_bar);
+        mSwitchBar.setSwitchBarText(R.string.mobile_network_use_sim_on,
+                R.string.mobile_network_use_sim_off);
+
+        mSwitchBar.addOnSwitchChangeListener((switchView, isChecked) -> {
+            if (mSubscriptionManager.isSubscriptionEnabled(mSubId) != isChecked) {
+                mSubscriptionManager.setSubscriptionEnabled(mSubId, isChecked);
+            }
+        });
+        update();
+    }
+
+    private void update() {
+        if (mSwitchBar == null) {
+            return;
+        }
+        final List<SubscriptionInfo> subs = SubscriptionUtil.getAvailableSubscriptions(
+                mSubscriptionManager);
+        if (mSubId == SubscriptionManager.INVALID_SUBSCRIPTION_ID || subs.size() < 2) {
+            mSwitchBar.hide();
+            return;
+        }
+
+        for (SubscriptionInfo info : subs) {
+            if (info.getSubscriptionId() == mSubId) {
+                mSwitchBar.show();
+                mSwitchBar.setChecked(mSubscriptionManager.isSubscriptionEnabled(mSubId));
+                return;
+            }
+        }
+        // This subscription was not found in the available list.
+        mSwitchBar.hide();
+    }
+
+    @Override
+    public int getAvailabilityStatus() {
+        if (FeatureFlagPersistent.isEnabled(mContext, FeatureFlags.NETWORK_INTERNET_V2)) {
+            return AVAILABLE_UNSEARCHABLE;
+        } else {
+            return CONDITIONALLY_UNAVAILABLE;
+        }
+    }
+
+    @Override
+    public void onAirplaneModeChanged(boolean airplaneModeEnabled) {}
+
+    @Override
+    public void onSubscriptionsChanged() {
+        update();
+    }
+}