Add default calls/SMS subscription prefs to mobile details page

This adds prefs to the the details page for mobile network subscriptions
that appear in multi-SIM mode. They show which subscription is set as
the default for calls and SMS respectively, and let the user change what
the default is for each. They can be set to either a specific
subscription, or set to "Ask every time".

Bug: 122670283
Test: make RunSettingsRoboTests
Change-Id: Id2b23e4b5c3d1b5c04b5766e73fc8202c05d8f75

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

@@ -0,0 +1,175 @@
+/*
+ * 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.network.SubscriptionUtil;
+import com.android.settings.network.SubscriptionsChangeListener;
+
+import java.util.List;
+
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.OnLifecycleEvent;
+import androidx.preference.ListPreference;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+/**
+ * This implements common controller functionality for a Preference letting the user see/change
+ * what mobile network subscription is used by default for some service controlled by the
+ * SubscriptionManager. This can be used for services such as Calls or SMS.
+ */
+public abstract class DefaultSubscriptionController extends BasePreferenceController implements
+        LifecycleObserver, Preference.OnPreferenceChangeListener,
+        SubscriptionsChangeListener.SubscriptionsChangeListenerClient {
+    private static final String TAG = "DefaultSubController";
+
+    protected SubscriptionsChangeListener mChangeListener;
+    protected ListPreference mPreference;
+    protected SubscriptionManager mManager;
+
+    public DefaultSubscriptionController(Context context, String preferenceKey) {
+        super(context, preferenceKey);
+        mManager = context.getSystemService(SubscriptionManager.class);
+        mChangeListener = new SubscriptionsChangeListener(context, this);
+    }
+
+    public void init(Lifecycle lifecycle) {
+        lifecycle.addObserver(this);
+    }
+
+    /** @return SubscriptionInfo for the default subscription for the service, or null if there
+     * isn't one. */
+    protected abstract SubscriptionInfo getDefaultSubscriptionInfo();
+
+    /** @return the id of the default subscription for the service, or
+     * SubscriptionManager.INVALID_SUBSCRIPTION_ID if there isn't one. */
+    protected abstract int getDefaultSubscriptionId();
+
+    /** Called to change the default subscription for the service. */
+    protected abstract void setDefaultSubscription(int subscriptionId);
+
+    @Override
+    public int getAvailabilityStatus() {
+        final List<SubscriptionInfo> subs = SubscriptionUtil.getAvailableSubscriptions(mManager);
+        if (subs.size() > 1) {
+            return AVAILABLE;
+        } else {
+            return CONDITIONALLY_UNAVAILABLE;
+        }
+    }
+
+    @OnLifecycleEvent(ON_RESUME)
+    public void onResume() {
+        mChangeListener.start();
+        updateEntries();
+    }
+
+    @OnLifecycleEvent(ON_PAUSE)
+    public void onPause() {
+        mChangeListener.stop();
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreference = screen.findPreference(getPreferenceKey());
+        updateEntries();
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        final SubscriptionInfo info = getDefaultSubscriptionInfo();
+        if (info != null) {
+            return info.getDisplayName();
+        } else {
+            return mContext.getString(R.string.calls_and_sms_ask_every_time);
+        }
+    }
+
+    private void updateEntries() {
+        if (mPreference == null) {
+            return;
+        }
+        if (!isAvailable()) {
+            mPreference.setVisible(false);
+            return;
+        }
+        mPreference.setVisible(true);
+
+        final List<SubscriptionInfo> subs = SubscriptionUtil.getAvailableSubscriptions(mManager);
+
+        // We'll have one entry for each available subscription, plus one for a "ask me every
+        // time" entry at the end.
+        final CharSequence[] displayNames = new CharSequence[subs.size() + 1];
+        final CharSequence[] subscriptionIds = new CharSequence[subs.size() + 1];
+
+        final int serviceDefaultSubId = getDefaultSubscriptionId();
+        boolean subIsAvailable = false;
+
+        int i = 0;
+        for (; i < subs.size(); i++) {
+            displayNames[i] = subs.get(i).getDisplayName();
+            final int subId = subs.get(i).getSubscriptionId();
+            subscriptionIds[i] = Integer.toString(subId);
+            if (subId == serviceDefaultSubId) {
+                subIsAvailable = true;
+            }
+        }
+        // Add the extra "Ask every time" value at the end.
+        displayNames[i] = mContext.getString(R.string.calls_and_sms_ask_every_time);
+        subscriptionIds[i] = Integer.toString(SubscriptionManager.INVALID_SUBSCRIPTION_ID);
+
+        mPreference.setEntries(displayNames);
+        mPreference.setEntryValues(subscriptionIds);
+
+        if (subIsAvailable) {
+            mPreference.setValue(Integer.toString(serviceDefaultSubId));
+        } else {
+            mPreference.setValue(Integer.toString(SubscriptionManager.INVALID_SUBSCRIPTION_ID));
+        }
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        final int subscriptionId = Integer.parseInt((String) newValue);
+        setDefaultSubscription(subscriptionId);
+        refreshSummary(mPreference);
+        return true;
+    }
+
+    @Override
+    public void onAirplaneModeChanged(boolean airplaneModeEnabled) {
+    }
+
+    @Override
+    public void onSubscriptionsChanged() {
+        if (mPreference != null) {
+            updateEntries();
+            refreshSummary(mPreference);
+        }
+    }
+}