packages/ExtServices/src/android/ext/services/notification/SmsHelper.java

/**
 * 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 android.ext.services.notification;

import static android.provider.Telephony.Sms.Intents.ACTION_DEFAULT_SMS_PACKAGE_CHANGED_INTERNAL;

import android.annotation.Nullable;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;

import com.android.internal.telephony.SmsApplication;

/**
 * A helper class for storing and retrieving the default SMS application.
 */
public class SmsHelper {
    private static final String TAG = "SmsHelper";

    private static SmsHelper sSmsHelper;
    private static final Object sLock = new Object();

    private final Context mContext;
    private ComponentName mDefaultSmsApplication;
    private BroadcastReceiver mBroadcastReceiver;

    static SmsHelper getInstance(Context context) {
        synchronized (sLock) {
            if (sSmsHelper == null) {
                sSmsHelper = new SmsHelper(context);
            }
            return sSmsHelper;
        }
    }

    private SmsHelper(Context context) {
        mContext = context.getApplicationContext();
    }

    void initialize() {
        if (mBroadcastReceiver == null) {
            mDefaultSmsApplication = SmsApplication.getDefaultSmsApplication(mContext, false);
            mBroadcastReceiver = new BroadcastReceiver() {
                @Override
                public void onReceive(Context context, Intent intent) {
                    if (ACTION_DEFAULT_SMS_PACKAGE_CHANGED_INTERNAL.equals(intent.getAction())) {
                        mDefaultSmsApplication =
                                SmsApplication.getDefaultSmsApplication(mContext, false);
                    } else {
                        Log.w(TAG, "Unknown broadcast received: " + intent.getAction());
                    }
                }
            };
            mContext.registerReceiver(
                    mBroadcastReceiver,
                    new IntentFilter(ACTION_DEFAULT_SMS_PACKAGE_CHANGED_INTERNAL));
        }
    }

    void destroy() {
        if (mBroadcastReceiver != null) {
            mContext.unregisterReceiver(mBroadcastReceiver);
            mBroadcastReceiver = null;
        }
    }

    @Nullable
    public ComponentName getDefaultSmsApplication() {
        return mDefaultSmsApplication;
    }
}