[Settings] Remaining part of Cross SIM calling (backup calling)

1. Change the wording
2. Add a list of summary within Calls and SMSs UI

Bug: 174012397
Test: manual
Change-Id: I6dde0cea9c1386029377b3ea2682ed8b977f9427

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

@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2020 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 android.content.Context;
+import android.os.PersistableBundle;
+import android.telephony.CarrierConfigManager;
+import android.telephony.SubscriptionInfo;
+import android.telephony.SubscriptionManager;
+import android.telephony.ims.ImsException;
+import android.telephony.ims.ImsManager;
+import android.telephony.ims.ImsMmTelManager;
+import android.util.Log;
+
+import androidx.preference.Preference;
+import androidx.preference.SwitchPreference;
+
+import com.android.settings.R;
+
+import java.util.Objects;
+
+/**
+ * Preference controller for "Backup Calling"
+ **/
+public class BackupCallingPreferenceController extends TelephonyTogglePreferenceController {
+
+    private static final String LOG_TAG = "BackupCallingPrefCtrl";
+
+    private int mSubId;
+    private Preference mPreference;
+
+    /**
+     * Class constructor of backup calling.
+     *
+     * @param context of settings
+     * @param key assigned within UI entry of XML file
+     **/
+    public BackupCallingPreferenceController(Context context, String key) {
+        super(context, key);
+    }
+
+    /**
+     * Initialization based on given subscription id.
+     *
+     * @param subId is the subscription id
+     * @return this instance after initialization
+     **/
+    public BackupCallingPreferenceController init(int subId) {
+        mSubId = subId;
+        return this;
+    }
+
+    @Override
+    public int getAvailabilityStatus(int subId) {
+        return hasBackupCallingFeature(subId) ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
+    }
+
+    /**
+     * Implementation of abstract methods
+     **/
+    public boolean setChecked(boolean isChecked) {
+        ImsMmTelManager imsMmTelMgr = getImsMmTelManager();
+        if (imsMmTelMgr == null) {
+            return false;
+        }
+        try {
+            imsMmTelMgr.setCrossSimCallingEnabled(isChecked);
+        } catch (ImsException exception) {
+            Log.w(LOG_TAG, "fail to change cross SIM calling configuration: " + isChecked,
+                    exception);
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Implementation of abstract methods
+     **/
+    public boolean isChecked() {
+        ImsMmTelManager imsMmTelMgr = getImsMmTelManager();
+        if (imsMmTelMgr == null) {
+            return false;
+        }
+        try {
+            return imsMmTelMgr.isCrossSimCallingEnabledByUser();
+        } catch (ImsException exception) {
+            Log.w(LOG_TAG, "fail to get cross SIM calling configuration", exception);
+        }
+        return false;
+    }
+
+    @Override
+    public void updateState(Preference preference) {
+        super.updateState(preference);
+        if ((preference == null) || (!(preference instanceof SwitchPreference))) {
+            return;
+        }
+        mPreference = preference;
+
+        final SwitchPreference switchPreference = (SwitchPreference) preference;
+        switchPreference.setChecked(isChecked());
+
+        updateSummary(getLatestSummary());
+    }
+
+    private String getLatestSummary() {
+        SubscriptionInfo subInfo = getSubscriptionInfo();
+        return Objects.toString((subInfo == null) ? null : subInfo.getDisplayName(), "");
+    }
+
+    private void updateSummary(String displayName) {
+        Preference preference = mPreference;
+        if (preference == null) {
+            return;
+        }
+        String summary = displayName;
+        String finalText = String.format(
+                getResourcesForSubId().getString(R.string.backup_calling_setting_summary),
+                summary)
+                .toString();
+        preference.setSummary(finalText);
+    }
+
+    private boolean hasBackupCallingFeature(int subscriptionId) {
+        PersistableBundle carrierConfig = getCarrierConfigForSubId(subscriptionId);
+        return (carrierConfig != null)
+                && carrierConfig.getBoolean(
+                CarrierConfigManager.KEY_CARRIER_CROSS_SIM_IMS_AVAILABLE_BOOL, false);
+    }
+
+    private ImsMmTelManager getImsMmTelManager() {
+        if (!SubscriptionManager.isUsableSubscriptionId(mSubId)) {
+            return null;
+        }
+        ImsManager imsMgr = mContext.getSystemService(ImsManager.class);
+        return (imsMgr == null) ? null : imsMgr.getImsMmTelManager(mSubId);
+    }
+
+    private SubscriptionInfo getSubscriptionInfo() {
+        SubscriptionManager subInfoMgr = mContext.getSystemService(SubscriptionManager.class);
+        if (subInfoMgr == null) {
+            return null;
+        }
+        return subInfoMgr.getActiveSubscriptionInfo(mSubId);
+    }
+}