src/com/android/cellbroadcastreceiver/CellBroadcastAlertAudio.java - platform/packages/apps/CellBroadcastReceiver - Git at Google

 /*
  * Copyright (C) 2011 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.cellbroadcastreceiver;

 import static com.android.cellbroadcastreceiver.CellBroadcastReceiver.DBG;
 import static com.android.cellbroadcastreceiver.CellBroadcastReceiver.VDBG;

 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.res.AssetFileDescriptor;
 import android.content.res.Resources;
 import android.media.AudioAttributes;
 import android.media.AudioDeviceInfo;
 import android.media.AudioManager;
 import android.media.MediaPlayer;
 import android.media.MediaPlayer.OnCompletionListener;
 import android.media.MediaPlayer.OnErrorListener;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Message;
 import android.os.Vibrator;
 import android.preference.PreferenceManager;
 import android.speech.tts.TextToSpeech;
 import android.telephony.PhoneStateListener;
 import android.telephony.TelephonyManager;
 import android.util.Log;

 import com.android.cellbroadcastreceiver.CellBroadcastAlertService.AlertType;

 import java.util.Locale;
 import java.util.MissingResourceException;

 /**
  * Manages alert audio and vibration and text-to-speech. Runs as a service so that
  * it can continue to play if another activity overrides the CellBroadcastListActivity.
  */
 public class CellBroadcastAlertAudio extends Service implements TextToSpeech.OnInitListener,
         TextToSpeech.OnUtteranceCompletedListener {
     private static final String TAG = "CellBroadcastAlertAudio";

     /** Action to start playing alert audio/vibration/speech. */
     static final String ACTION_START_ALERT_AUDIO = "ACTION_START_ALERT_AUDIO";

     /** Extra for message body to speak (if speech enabled in settings). */
     public static final String ALERT_AUDIO_MESSAGE_BODY =
             "com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_BODY";

     /** Extra for text-to-speech preferred language (if speech enabled in settings). */
     public static final String ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE =
             "com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE";

     /** Extra for text-to-speech default language when preferred language is
         not available (if speech enabled in settings). */
     public static final String ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE =
             "com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE";

     /** Extra for alert tone type */
     public static final String ALERT_AUDIO_TONE_TYPE =
             "com.android.cellbroadcastreceiver.ALERT_AUDIO_TONE_TYPE";

     /** Extra for alert audio vibration enabled (from settings). */
     public static final String ALERT_AUDIO_VIBRATE_EXTRA =
             "com.android.cellbroadcastreceiver.ALERT_AUDIO_VIBRATE";

     private static final String TTS_UTTERANCE_ID = "com.android.cellbroadcastreceiver.UTTERANCE_ID";

     /** Pause duration between alert sound and alert speech. */
     private static final int PAUSE_DURATION_BEFORE_SPEAKING_MSEC = 1000;

     private static final int STATE_IDLE = 0;
     private static final int STATE_ALERTING = 1;
     private static final int STATE_PAUSING = 2;
     private static final int STATE_SPEAKING = 3;

     private int mState;

     private TextToSpeech mTts;
     private boolean mTtsEngineReady;

     private String mMessageBody;
     private String mMessagePreferredLanguage;
     private String mMessageDefaultLanguage;
     private boolean mTtsLanguageSupported;
     private boolean mEnableVibrate;
     private boolean mEnableAudio;
     private boolean mUseFullVolume;
     private boolean mResetAlarmVolumeNeeded;
     private int mUserSetAlarmVolume;

     private Vibrator mVibrator;
     private MediaPlayer mMediaPlayer;
     private AudioManager mAudioManager;
     private TelephonyManager mTelephonyManager;
     private int mInitialCallState;
     private PackageManager mPackageManager;

     // Internal messages
     private static final int ALERT_SOUND_FINISHED = 1000;
     private static final int ALERT_PAUSE_FINISHED = 1001;
     private final Handler mHandler = new Handler() {
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case ALERT_SOUND_FINISHED:
                     if (DBG) log("ALERT_SOUND_FINISHED");
                     stop();     // stop alert sound
                     // if we can speak the message text
                     if (mMessageBody != null && mTtsEngineReady && mTtsLanguageSupported) {
                         mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_PAUSE_FINISHED),
                                 PAUSE_DURATION_BEFORE_SPEAKING_MSEC);
                         mState = STATE_PAUSING;
                     } else {
                         if (DBG) log("MessageEmpty = " + (mMessageBody == null) +
                                 ", mTtsEngineReady = " + mTtsEngineReady +
                                 ", mTtsLanguageSupported = " + mTtsLanguageSupported);
                         stopSelf();
                         mState = STATE_IDLE;
                     }
                     // Set alert reminder depending on user preference
                     CellBroadcastAlertReminder.queueAlertReminder(getApplicationContext(), true);
                     break;

                 case ALERT_PAUSE_FINISHED:
                     if (DBG) log("ALERT_PAUSE_FINISHED");
                     int res = TextToSpeech.ERROR;
                     if (mMessageBody != null && mTtsEngineReady && mTtsLanguageSupported) {
                         if (DBG) log("Speaking broadcast text: " + mMessageBody);

                         Bundle params = new Bundle();
                         // Play TTS in notification stream.
                         params.putInt(TextToSpeech.Engine.KEY_PARAM_STREAM,
                                 AudioManager.STREAM_NOTIFICATION);
                         // Use the non-public parameter 2 --> TextToSpeech.QUEUE_DESTROY for TTS.
                         // The entire playback queue is purged. This is different from QUEUE_FLUSH
                         // in that all entries are purged, not just entries from a given caller.
                         // This is for emergency so we want to kill all other TTS sessions.
                         res = mTts.speak(mMessageBody, 2, params, TTS_UTTERANCE_ID);
                         mState = STATE_SPEAKING;
                     }
                     if (res != TextToSpeech.SUCCESS) {
                         loge("TTS engine not ready or language not supported or speak() failed");
                         stopSelf();
                         mState = STATE_IDLE;
                     }
                     break;

                 default:
                     loge("Handler received unknown message, what=" + msg.what);
             }
         }
     };

     private final PhoneStateListener mPhoneStateListener = new PhoneStateListener() {
         @Override
         public void onCallStateChanged(int state, String ignored) {
             // Stop the alert sound and speech if the call state changes.
             if (state != TelephonyManager.CALL_STATE_IDLE
                     && state != mInitialCallState) {
                 stopSelf();
             }
         }
     };

     /**
      * Callback from TTS engine after initialization.
      * @param status {@link TextToSpeech#SUCCESS} or {@link TextToSpeech#ERROR}.
      */
     @Override
     public void onInit(int status) {
         if (VDBG) log("onInit() TTS engine status: " + status);
         if (status == TextToSpeech.SUCCESS) {
             mTtsEngineReady = true;
             mTts.setOnUtteranceCompletedListener(this);
             // try to set the TTS language to match the broadcast
             setTtsLanguage();
         } else {
             mTtsEngineReady = false;
             mTts = null;
             loge("onInit() TTS engine error: " + status);
         }
     }

     /**
      * Try to set the TTS engine language to the preferred language. If failed, set
      * it to the default language. mTtsLanguageSupported will be updated based on the response.
      */
     private void setTtsLanguage() {

         String language = mMessagePreferredLanguage;
         if (language == null || language.isEmpty() ||
                 TextToSpeech.LANG_AVAILABLE != mTts.isLanguageAvailable(new Locale(language))) {
             language = mMessageDefaultLanguage;
             if (language == null || language.isEmpty() ||
                     TextToSpeech.LANG_AVAILABLE != mTts.isLanguageAvailable(new Locale(language))) {
                 mTtsLanguageSupported = false;
                 return;
             }
             if (DBG) log("Language '" + mMessagePreferredLanguage + "' is not available, using" +
                     "the default language '" + mMessageDefaultLanguage + "'");
         }

         if (DBG) log("Setting TTS language to '" + language + '\'');

         try {
             int result = mTts.setLanguage(new Locale(language));
             if (DBG) log("TTS setLanguage() returned: " + result);
             mTtsLanguageSupported = (result == TextToSpeech.LANG_AVAILABLE);
         }
         catch (MissingResourceException e) {
             mTtsLanguageSupported = false;
             loge("Language '" + language + "' is not available.");
         }
     }

     /**
      * Callback from TTS engine.
      * @param utteranceId the identifier of the utterance.
      */
     @Override
     public void onUtteranceCompleted(String utteranceId) {
         if (utteranceId.equals(TTS_UTTERANCE_ID)) {
             // When we reach here, it could be TTS completed or TTS was cut due to another
             // new alert started playing. We don't want to stop the service in the later case.
             if (mState == STATE_SPEAKING) {
                 stopSelf();
             }
         }
     }

     @Override
     public void onCreate() {
         mVibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
         mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
         // Listen for incoming calls to kill the alarm.
         mTelephonyManager =
                 (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
         mTelephonyManager.listen(
                 mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);
         mPackageManager = getPackageManager();
     }

     @Override
     public void onDestroy() {
         // stop audio, vibration and TTS
         stop();
         // Stop listening for incoming calls.
         mTelephonyManager.listen(mPhoneStateListener, 0);
         // shutdown TTS engine
         if (mTts != null) {
             try {
                 mTts.shutdown();
             } catch (IllegalStateException e) {
                 // catch "Unable to retrieve AudioTrack pointer for stop()" exception
                 loge("exception trying to shutdown text-to-speech");
             }
         }
         if (mEnableAudio) {
             // Release the audio focus so other audio (e.g. music) can resume.
             // Do not do this in stop() because stop() is also called when we stop the tone (before
             // TTS is playing). We only want to release the focus when tone and TTS are played.
             mAudioManager.abandonAudioFocus(null);
         }
         // release the screen bright wakelock acquired by CellBroadcastAlertService
         CellBroadcastAlertWakeLock.releaseScreenBrightWakeLock();
     }

     @Override
     public IBinder onBind(Intent intent) {
         return null;
     }

     @Override
     public int onStartCommand(Intent intent, int flags, int startId) {
         // No intent, tell the system not to restart us.
         if (intent == null) {
             stopSelf();
             return START_NOT_STICKY;
         }

         // Get text to speak (if enabled by user)
         mMessageBody = intent.getStringExtra(ALERT_AUDIO_MESSAGE_BODY);
         mMessagePreferredLanguage = intent.getStringExtra(ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE);
         mMessageDefaultLanguage = intent.getStringExtra(ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE);

         // Get config of whether to always sound CBS alerts at full volume.
         mUseFullVolume = PreferenceManager.getDefaultSharedPreferences(this)
                 .getBoolean(CellBroadcastSettings.KEY_USE_FULL_VOLUME, false);

         // retrieve the vibrate settings from cellbroadcast receiver settings.
         mEnableVibrate = intent.getBooleanExtra(ALERT_AUDIO_VIBRATE_EXTRA, true);
         switch (mAudioManager.getRingerMode()) {
             case AudioManager.RINGER_MODE_SILENT:
                 if (DBG) log("Ringer mode: silent");
                 mEnableAudio = false;
                 mEnableVibrate = false;
                 break;
             case AudioManager.RINGER_MODE_VIBRATE:
                 if (DBG) log("Ringer mode: vibrate");
                 mEnableAudio = false;
                 break;
             case AudioManager.RINGER_MODE_NORMAL:
             default:
                 if (DBG) log("Ringer mode: normal");
                 mEnableAudio = true;
                 break;
         }

         if (mUseFullVolume) {
             mEnableAudio = true;
         }

         if (mMessageBody != null && mEnableAudio) {
             if (mTts == null) {
                 mTts = new TextToSpeech(this, this);
             } else if (mTtsEngineReady) {
                 setTtsLanguage();
             }
         }

         if (mEnableAudio || mEnableVibrate) {
             AlertType alertType = AlertType.CMAS_DEFAULT;
             if (intent.getSerializableExtra(ALERT_AUDIO_TONE_TYPE) != null) {
                 alertType = (AlertType) intent.getSerializableExtra(ALERT_AUDIO_TONE_TYPE);
             }
             playAlertTone(alertType);
         } else {
             stopSelf();
             return START_NOT_STICKY;
         }

         // Record the initial call state here so that the new alarm has the
         // newest state.
         mInitialCallState = mTelephonyManager.getCallState();

         return START_STICKY;
     }

     // Volume suggested by media team for in-call alarms.
     private static final float IN_CALL_VOLUME = 0.125f;

     /**
      * Start playing the alert sound.
      * @param alertType the alert type (e.g. default, earthquake, tsunami, etc..)
      */
     private void playAlertTone(AlertType alertType) {
         // stop() checks to see if we are already playing.
         stop();

         log("playAlertTone: alertType=" + alertType);

         // Vibration duration in milliseconds
         long vibrateDuration = 0;

         int customAlertDuration = getResources().getInteger(R.integer.alert_duration);

         // Start the vibration first.
         if (mEnableVibrate) {

             int[] patternArray = getApplicationContext().getResources().
                     getIntArray(R.array.default_vibration_pattern);
             long[] vibrationPattern = new long[patternArray.length];

             for (int i = 0; i < patternArray.length; i++) {
                 vibrationPattern[i] = patternArray[i];
                 vibrateDuration += patternArray[i];
             }
             mVibrator.vibrate(vibrationPattern, 0);
         }


         if (mEnableAudio) {
             // future optimization: reuse media player object
             mMediaPlayer = new MediaPlayer();
             mMediaPlayer.setOnErrorListener(new OnErrorListener() {
                 public boolean onError(MediaPlayer mp, int what, int extra) {
                     loge("Error occurred while playing audio.");
                     mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
                     return true;
                 }
             });

             // If the duration is specified by the config, use the specified duration. Otherwise,
             // just play the alert tone with the tone's duration.
             if (customAlertDuration >= 0) {
                 mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_SOUND_FINISHED),
                         customAlertDuration);
             } else {
                 mMediaPlayer.setOnCompletionListener(new OnCompletionListener() {
                     public void onCompletion(MediaPlayer mp) {
                         if (DBG) log("Audio playback complete.");
                         mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
                         return;
                     }
                 });
             }

             try {
                 log("Locale=" + getResources().getConfiguration().getLocales());

                 // Load the tones based on type
                 switch (alertType) {
                     case EARTHQUAKE:
                         setDataSourceFromResource(getResources(), mMediaPlayer,
                                 R.raw.etws_earthquake);
                         break;
                     case TSUNAMI:
                         setDataSourceFromResource(getResources(), mMediaPlayer,
                                 R.raw.etws_tsunami);
                         break;
                     case OTHER:
                         setDataSourceFromResource(getResources(), mMediaPlayer,
                                 R.raw.etws_other_disaster);
                         break;
                     case ETWS_DEFAULT:
                         setDataSourceFromResource(getResources(), mMediaPlayer,
                                 R.raw.etws_default);
                         break;
                     case CMAS_DEFAULT:
                     default:
                         setDataSourceFromResource(getResources(), mMediaPlayer,
                                 R.raw.cmas_default);
                 }


                 if (!mPackageManager.hasSystemFeature(PackageManager.FEATURE_WATCH)) {
                     // start playing alert audio (unless master volume is vibrate only or silent).
                     mAudioManager.requestAudioFocus(null, AudioManager.STREAM_ALARM,
                             AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
                 } else {
                     mMediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
                 }

                 setAlertAudioAttributes();
                 setAlertVolume();

                 // If we are using the custom alert duration, set looping to true so we can repeat
                 // the alert. The tone playing will stop when ALERT_SOUND_FINISHED arrives.
                 // Otherwise we just play the alert tone once.
                 mMediaPlayer.setLooping(customAlertDuration >= 0);
                 mMediaPlayer.prepare();
                 mMediaPlayer.start();

             } catch (Exception ex) {
                 loge("Failed to play alert sound: " + ex);
                 // Immediately move into the next state ALERT_SOUND_FINISHED.
                 mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
             }
         } else {
             // In normal mode (playing tone + vibration), this service will stop after audio
             // playback is done. However, if the device is in vibrate only mode, we need to stop
             // the service right after vibration because there won't be any audio complete callback
             // to stop the service. Unfortunately it's not like MediaPlayer has onCompletion()
             // callback that we can use, we'll have to use our own timer to stop the service.
             mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_SOUND_FINISHED),
                     customAlertDuration >= 0 ? customAlertDuration : vibrateDuration);
         }

         mState = STATE_ALERTING;
     }

     private static void setDataSourceFromResource(Resources resources,
             MediaPlayer player, int res) throws java.io.IOException {
         AssetFileDescriptor afd = resources.openRawResourceFd(res);
         if (afd != null) {
             player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(),
                     afd.getLength());
             afd.close();
         }
     }

     /**
      * Stops alert audio and speech.
      */
     public void stop() {
         if (DBG) log("stop()");

         mHandler.removeMessages(ALERT_SOUND_FINISHED);
         mHandler.removeMessages(ALERT_PAUSE_FINISHED);

         resetAlarmStreamVolume();

         if (mState == STATE_ALERTING) {
             // Stop audio playing
             if (mMediaPlayer != null) {
                 try {
                     mMediaPlayer.stop();
                     mMediaPlayer.release();
                 } catch (IllegalStateException e) {
                     // catch "Unable to retrieve AudioTrack pointer for stop()" exception
                     loge("exception trying to stop media player");
                 }
                 mMediaPlayer = null;
             }

             // Stop vibrator
             mVibrator.cancel();
         } else if (mState == STATE_SPEAKING && mTts != null) {
             try {
                 mTts.stop();
             } catch (IllegalStateException e) {
                 // catch "Unable to retrieve AudioTrack pointer for stop()" exception
                 loge("exception trying to stop text-to-speech");
             }
         }
         mState = STATE_IDLE;
     }

     /**
      * Set AudioAttributes for mMediaPlayer. Replacement of deprecated
      * mMediaPlayer.setAudioStreamType.
      */
     private void setAlertAudioAttributes() {
         AudioAttributes.Builder builder = new AudioAttributes.Builder();

         builder.setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION);
         builder.setUsage(AudioAttributes.USAGE_ALARM);
         if (mUseFullVolume) {
             // Set FLAG_BYPASS_INTERRUPTION_POLICY so that it still enables
             // audio in DnD mode (except total silence DnD mode).
             builder.setFlags(AudioAttributes.FLAG_BYPASS_INTERRUPTION_POLICY);
         }

         mMediaPlayer.setAudioAttributes(builder.build());
     }

     /**
      * Set volume for alerts.
      */
     private void setAlertVolume() {
         if (mTelephonyManager.getCallState() != TelephonyManager.CALL_STATE_IDLE
                 || isOnEarphone()) {
             // If we are in a call, play the alert
             // sound at a low volume to not disrupt the call.
             log("in call: reducing volume");
             mMediaPlayer.setVolume(IN_CALL_VOLUME);
         } else if (mUseFullVolume) {
             // If use_full_volume is configured,
             // we overwrite volume setting of STREAM_ALARM to full, play at
             // max possible volume, and reset it after it's finished.
             setAlarmStreamVolumeToFull();
         }
     }

     private boolean isOnEarphone() {
         AudioDeviceInfo[] deviceList = mAudioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);

         for (AudioDeviceInfo devInfo : deviceList) {
             int type = devInfo.getType();
             if (type == AudioDeviceInfo.TYPE_WIRED_HEADSET
                     || type == AudioDeviceInfo.TYPE_WIRED_HEADPHONES
                     || type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO
                     || type == AudioDeviceInfo.TYPE_BLUETOOTH_A2DP) {
                 return true;
             }
         }

         return false;
     }

     /**
      * Set volume of STREAM_ALARM to full.
      */
     private void setAlarmStreamVolumeToFull() {
         log("setting alarm volume to full for cell broadcast alerts.");
         mUserSetAlarmVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_ALARM);
         mResetAlarmVolumeNeeded = true;
         mAudioManager.setStreamVolume(AudioManager.STREAM_ALARM,
                 mAudioManager.getStreamMaxVolume(AudioManager.STREAM_ALARM),
                 0);
     }

     /**
      * Reset volume of STREAM_ALARM, if needed.
      */
     private void resetAlarmStreamVolume() {
         if (mResetAlarmVolumeNeeded) {
             log("resetting alarm volume to back to " + mUserSetAlarmVolume);
             mAudioManager.setStreamVolume(AudioManager.STREAM_ALARM, mUserSetAlarmVolume, 0);
             mResetAlarmVolumeNeeded = false;
         }
     }

     private static void log(String msg) {
         Log.d(TAG, msg);
     }

     private static void loge(String msg) {
         Log.e(TAG, msg);
     }
 }
	/*
	* Copyright (C) 2011 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.cellbroadcastreceiver;

	import static com.android.cellbroadcastreceiver.CellBroadcastReceiver.DBG;
	import static com.android.cellbroadcastreceiver.CellBroadcastReceiver.VDBG;

	import android.app.Service;
	import android.content.Context;
	import android.content.Intent;
	import android.content.pm.PackageManager;
	import android.content.res.AssetFileDescriptor;
	import android.content.res.Resources;
	import android.media.AudioAttributes;
	import android.media.AudioDeviceInfo;
	import android.media.AudioManager;
	import android.media.MediaPlayer;
	import android.media.MediaPlayer.OnCompletionListener;
	import android.media.MediaPlayer.OnErrorListener;
	import android.os.Bundle;
	import android.os.Handler;
	import android.os.IBinder;
	import android.os.Message;
	import android.os.Vibrator;
	import android.preference.PreferenceManager;
	import android.speech.tts.TextToSpeech;
	import android.telephony.PhoneStateListener;
	import android.telephony.TelephonyManager;
	import android.util.Log;

	import com.android.cellbroadcastreceiver.CellBroadcastAlertService.AlertType;

	import java.util.Locale;
	import java.util.MissingResourceException;

	/**
	* Manages alert audio and vibration and text-to-speech. Runs as a service so that
	* it can continue to play if another activity overrides the CellBroadcastListActivity.
	*/
	public class CellBroadcastAlertAudio extends Service implements TextToSpeech.OnInitListener,
	TextToSpeech.OnUtteranceCompletedListener {
	private static final String TAG = "CellBroadcastAlertAudio";

	/** Action to start playing alert audio/vibration/speech. */
	static final String ACTION_START_ALERT_AUDIO = "ACTION_START_ALERT_AUDIO";

	/** Extra for message body to speak (if speech enabled in settings). */
	public static final String ALERT_AUDIO_MESSAGE_BODY =
	"com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_BODY";

	/** Extra for text-to-speech preferred language (if speech enabled in settings). */
	public static final String ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE =
	"com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE";

	/** Extra for text-to-speech default language when preferred language is
	not available (if speech enabled in settings). */
	public static final String ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE =
	"com.android.cellbroadcastreceiver.ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE";

	/** Extra for alert tone type */
	public static final String ALERT_AUDIO_TONE_TYPE =
	"com.android.cellbroadcastreceiver.ALERT_AUDIO_TONE_TYPE";

	/** Extra for alert audio vibration enabled (from settings). */
	public static final String ALERT_AUDIO_VIBRATE_EXTRA =
	"com.android.cellbroadcastreceiver.ALERT_AUDIO_VIBRATE";

	private static final String TTS_UTTERANCE_ID = "com.android.cellbroadcastreceiver.UTTERANCE_ID";

	/** Pause duration between alert sound and alert speech. */
	private static final int PAUSE_DURATION_BEFORE_SPEAKING_MSEC = 1000;

	private static final int STATE_IDLE = 0;
	private static final int STATE_ALERTING = 1;
	private static final int STATE_PAUSING = 2;
	private static final int STATE_SPEAKING = 3;

	private int mState;

	private TextToSpeech mTts;
	private boolean mTtsEngineReady;

	private String mMessageBody;
	private String mMessagePreferredLanguage;
	private String mMessageDefaultLanguage;
	private boolean mTtsLanguageSupported;
	private boolean mEnableVibrate;
	private boolean mEnableAudio;
	private boolean mUseFullVolume;
	private boolean mResetAlarmVolumeNeeded;
	private int mUserSetAlarmVolume;

	private Vibrator mVibrator;
	private MediaPlayer mMediaPlayer;
	private AudioManager mAudioManager;
	private TelephonyManager mTelephonyManager;
	private int mInitialCallState;
	private PackageManager mPackageManager;

	// Internal messages
	private static final int ALERT_SOUND_FINISHED = 1000;
	private static final int ALERT_PAUSE_FINISHED = 1001;
	private final Handler mHandler = new Handler() {
	@Override
	public void handleMessage(Message msg) {
	switch (msg.what) {
	case ALERT_SOUND_FINISHED:
	if (DBG) log("ALERT_SOUND_FINISHED");
	stop(); // stop alert sound
	// if we can speak the message text
	if (mMessageBody != null && mTtsEngineReady && mTtsLanguageSupported) {
	mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_PAUSE_FINISHED),
	PAUSE_DURATION_BEFORE_SPEAKING_MSEC);
	mState = STATE_PAUSING;
	} else {
	if (DBG) log("MessageEmpty = " + (mMessageBody == null) +
	", mTtsEngineReady = " + mTtsEngineReady +
	", mTtsLanguageSupported = " + mTtsLanguageSupported);
	stopSelf();
	mState = STATE_IDLE;
	}
	// Set alert reminder depending on user preference
	CellBroadcastAlertReminder.queueAlertReminder(getApplicationContext(), true);
	break;

	case ALERT_PAUSE_FINISHED:
	if (DBG) log("ALERT_PAUSE_FINISHED");
	int res = TextToSpeech.ERROR;
	if (mMessageBody != null && mTtsEngineReady && mTtsLanguageSupported) {
	if (DBG) log("Speaking broadcast text: " + mMessageBody);

	Bundle params = new Bundle();
	// Play TTS in notification stream.
	params.putInt(TextToSpeech.Engine.KEY_PARAM_STREAM,
	AudioManager.STREAM_NOTIFICATION);
	// Use the non-public parameter 2 --> TextToSpeech.QUEUE_DESTROY for TTS.
	// The entire playback queue is purged. This is different from QUEUE_FLUSH
	// in that all entries are purged, not just entries from a given caller.
	// This is for emergency so we want to kill all other TTS sessions.
	res = mTts.speak(mMessageBody, 2, params, TTS_UTTERANCE_ID);
	mState = STATE_SPEAKING;
	}
	if (res != TextToSpeech.SUCCESS) {
	loge("TTS engine not ready or language not supported or speak() failed");
	stopSelf();
	mState = STATE_IDLE;
	}
	break;

	default:
	loge("Handler received unknown message, what=" + msg.what);
	}
	}
	};

	private final PhoneStateListener mPhoneStateListener = new PhoneStateListener() {
	@Override
	public void onCallStateChanged(int state, String ignored) {
	// Stop the alert sound and speech if the call state changes.
	if (state != TelephonyManager.CALL_STATE_IDLE
	&& state != mInitialCallState) {
	stopSelf();
	}
	}
	};

	/**
	* Callback from TTS engine after initialization.
	* @param status {@link TextToSpeech#SUCCESS} or {@link TextToSpeech#ERROR}.
	*/
	@Override
	public void onInit(int status) {
	if (VDBG) log("onInit() TTS engine status: " + status);
	if (status == TextToSpeech.SUCCESS) {
	mTtsEngineReady = true;
	mTts.setOnUtteranceCompletedListener(this);
	// try to set the TTS language to match the broadcast
	setTtsLanguage();
	} else {
	mTtsEngineReady = false;
	mTts = null;
	loge("onInit() TTS engine error: " + status);
	}
	}

	/**
	* Try to set the TTS engine language to the preferred language. If failed, set
	* it to the default language. mTtsLanguageSupported will be updated based on the response.
	*/
	private void setTtsLanguage() {

	String language = mMessagePreferredLanguage;
	if (language == null \|\| language.isEmpty() \|\|
	TextToSpeech.LANG_AVAILABLE != mTts.isLanguageAvailable(new Locale(language))) {
	language = mMessageDefaultLanguage;
	if (language == null \|\| language.isEmpty() \|\|
	TextToSpeech.LANG_AVAILABLE != mTts.isLanguageAvailable(new Locale(language))) {
	mTtsLanguageSupported = false;
	return;
	}
	if (DBG) log("Language '" + mMessagePreferredLanguage + "' is not available, using" +
	"the default language '" + mMessageDefaultLanguage + "'");
	}

	if (DBG) log("Setting TTS language to '" + language + '\'');

	try {
	int result = mTts.setLanguage(new Locale(language));
	if (DBG) log("TTS setLanguage() returned: " + result);
	mTtsLanguageSupported = (result == TextToSpeech.LANG_AVAILABLE);
	}
	catch (MissingResourceException e) {
	mTtsLanguageSupported = false;
	loge("Language '" + language + "' is not available.");
	}
	}

	/**
	* Callback from TTS engine.
	* @param utteranceId the identifier of the utterance.
	*/
	@Override
	public void onUtteranceCompleted(String utteranceId) {
	if (utteranceId.equals(TTS_UTTERANCE_ID)) {
	// When we reach here, it could be TTS completed or TTS was cut due to another
	// new alert started playing. We don't want to stop the service in the later case.
	if (mState == STATE_SPEAKING) {
	stopSelf();
	}
	}
	}

	@Override
	public void onCreate() {
	mVibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
	mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
	// Listen for incoming calls to kill the alarm.
	mTelephonyManager =
	(TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
	mTelephonyManager.listen(
	mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE);
	mPackageManager = getPackageManager();
	}

	@Override
	public void onDestroy() {
	// stop audio, vibration and TTS
	stop();
	// Stop listening for incoming calls.
	mTelephonyManager.listen(mPhoneStateListener, 0);
	// shutdown TTS engine
	if (mTts != null) {
	try {
	mTts.shutdown();
	} catch (IllegalStateException e) {
	// catch "Unable to retrieve AudioTrack pointer for stop()" exception
	loge("exception trying to shutdown text-to-speech");
	}
	}
	if (mEnableAudio) {
	// Release the audio focus so other audio (e.g. music) can resume.
	// Do not do this in stop() because stop() is also called when we stop the tone (before
	// TTS is playing). We only want to release the focus when tone and TTS are played.
	mAudioManager.abandonAudioFocus(null);
	}
	// release the screen bright wakelock acquired by CellBroadcastAlertService
	CellBroadcastAlertWakeLock.releaseScreenBrightWakeLock();
	}

	@Override
	public IBinder onBind(Intent intent) {
	return null;
	}

	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
	// No intent, tell the system not to restart us.
	if (intent == null) {
	stopSelf();
	return START_NOT_STICKY;
	}

	// Get text to speak (if enabled by user)
	mMessageBody = intent.getStringExtra(ALERT_AUDIO_MESSAGE_BODY);
	mMessagePreferredLanguage = intent.getStringExtra(ALERT_AUDIO_MESSAGE_PREFERRED_LANGUAGE);
	mMessageDefaultLanguage = intent.getStringExtra(ALERT_AUDIO_MESSAGE_DEFAULT_LANGUAGE);

	// Get config of whether to always sound CBS alerts at full volume.
	mUseFullVolume = PreferenceManager.getDefaultSharedPreferences(this)
	.getBoolean(CellBroadcastSettings.KEY_USE_FULL_VOLUME, false);

	// retrieve the vibrate settings from cellbroadcast receiver settings.
	mEnableVibrate = intent.getBooleanExtra(ALERT_AUDIO_VIBRATE_EXTRA, true);
	switch (mAudioManager.getRingerMode()) {
	case AudioManager.RINGER_MODE_SILENT:
	if (DBG) log("Ringer mode: silent");
	mEnableAudio = false;
	mEnableVibrate = false;
	break;
	case AudioManager.RINGER_MODE_VIBRATE:
	if (DBG) log("Ringer mode: vibrate");
	mEnableAudio = false;
	break;
	case AudioManager.RINGER_MODE_NORMAL:
	default:
	if (DBG) log("Ringer mode: normal");
	mEnableAudio = true;
	break;
	}

	if (mUseFullVolume) {
	mEnableAudio = true;
	}

	if (mMessageBody != null && mEnableAudio) {
	if (mTts == null) {
	mTts = new TextToSpeech(this, this);
	} else if (mTtsEngineReady) {
	setTtsLanguage();
	}
	}

	if (mEnableAudio \|\| mEnableVibrate) {
	AlertType alertType = AlertType.CMAS_DEFAULT;
	if (intent.getSerializableExtra(ALERT_AUDIO_TONE_TYPE) != null) {
	alertType = (AlertType) intent.getSerializableExtra(ALERT_AUDIO_TONE_TYPE);
	}
	playAlertTone(alertType);
	} else {
	stopSelf();
	return START_NOT_STICKY;
	}

	// Record the initial call state here so that the new alarm has the
	// newest state.
	mInitialCallState = mTelephonyManager.getCallState();

	return START_STICKY;
	}

	// Volume suggested by media team for in-call alarms.
	private static final float IN_CALL_VOLUME = 0.125f;

	/**
	* Start playing the alert sound.
	* @param alertType the alert type (e.g. default, earthquake, tsunami, etc..)
	*/
	private void playAlertTone(AlertType alertType) {
	// stop() checks to see if we are already playing.
	stop();

	log("playAlertTone: alertType=" + alertType);

	// Vibration duration in milliseconds
	long vibrateDuration = 0;

	int customAlertDuration = getResources().getInteger(R.integer.alert_duration);

	// Start the vibration first.
	if (mEnableVibrate) {

	int[] patternArray = getApplicationContext().getResources().
	getIntArray(R.array.default_vibration_pattern);
	long[] vibrationPattern = new long[patternArray.length];

	for (int i = 0; i < patternArray.length; i++) {
	vibrationPattern[i] = patternArray[i];
	vibrateDuration += patternArray[i];
	}
	mVibrator.vibrate(vibrationPattern, 0);
	}


	if (mEnableAudio) {
	// future optimization: reuse media player object
	mMediaPlayer = new MediaPlayer();
	mMediaPlayer.setOnErrorListener(new OnErrorListener() {
	public boolean onError(MediaPlayer mp, int what, int extra) {
	loge("Error occurred while playing audio.");
	mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
	return true;
	}
	});

	// If the duration is specified by the config, use the specified duration. Otherwise,
	// just play the alert tone with the tone's duration.
	if (customAlertDuration >= 0) {
	mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_SOUND_FINISHED),
	customAlertDuration);
	} else {
	mMediaPlayer.setOnCompletionListener(new OnCompletionListener() {
	public void onCompletion(MediaPlayer mp) {
	if (DBG) log("Audio playback complete.");
	mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
	return;
	}
	});
	}

	try {
	log("Locale=" + getResources().getConfiguration().getLocales());

	// Load the tones based on type
	switch (alertType) {
	case EARTHQUAKE:
	setDataSourceFromResource(getResources(), mMediaPlayer,
	R.raw.etws_earthquake);
	break;
	case TSUNAMI:
	setDataSourceFromResource(getResources(), mMediaPlayer,
	R.raw.etws_tsunami);
	break;
	case OTHER:
	setDataSourceFromResource(getResources(), mMediaPlayer,
	R.raw.etws_other_disaster);
	break;
	case ETWS_DEFAULT:
	setDataSourceFromResource(getResources(), mMediaPlayer,
	R.raw.etws_default);
	break;
	case CMAS_DEFAULT:
	default:
	setDataSourceFromResource(getResources(), mMediaPlayer,
	R.raw.cmas_default);
	}


	if (!mPackageManager.hasSystemFeature(PackageManager.FEATURE_WATCH)) {
	// start playing alert audio (unless master volume is vibrate only or silent).
	mAudioManager.requestAudioFocus(null, AudioManager.STREAM_ALARM,
	AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
	} else {
	mMediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
	}

	setAlertAudioAttributes();
	setAlertVolume();

	// If we are using the custom alert duration, set looping to true so we can repeat
	// the alert. The tone playing will stop when ALERT_SOUND_FINISHED arrives.
	// Otherwise we just play the alert tone once.
	mMediaPlayer.setLooping(customAlertDuration >= 0);
	mMediaPlayer.prepare();
	mMediaPlayer.start();

	} catch (Exception ex) {
	loge("Failed to play alert sound: " + ex);
	// Immediately move into the next state ALERT_SOUND_FINISHED.
	mHandler.sendMessage(mHandler.obtainMessage(ALERT_SOUND_FINISHED));
	}
	} else {
	// In normal mode (playing tone + vibration), this service will stop after audio
	// playback is done. However, if the device is in vibrate only mode, we need to stop
	// the service right after vibration because there won't be any audio complete callback
	// to stop the service. Unfortunately it's not like MediaPlayer has onCompletion()
	// callback that we can use, we'll have to use our own timer to stop the service.
	mHandler.sendMessageDelayed(mHandler.obtainMessage(ALERT_SOUND_FINISHED),
	customAlertDuration >= 0 ? customAlertDuration : vibrateDuration);
	}

	mState = STATE_ALERTING;
	}

	private static void setDataSourceFromResource(Resources resources,
	MediaPlayer player, int res) throws java.io.IOException {
	AssetFileDescriptor afd = resources.openRawResourceFd(res);
	if (afd != null) {
	player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(),
	afd.getLength());
	afd.close();
	}
	}

	/**
	* Stops alert audio and speech.
	*/
	public void stop() {
	if (DBG) log("stop()");

	mHandler.removeMessages(ALERT_SOUND_FINISHED);
	mHandler.removeMessages(ALERT_PAUSE_FINISHED);

	resetAlarmStreamVolume();

	if (mState == STATE_ALERTING) {
	// Stop audio playing
	if (mMediaPlayer != null) {
	try {
	mMediaPlayer.stop();
	mMediaPlayer.release();
	} catch (IllegalStateException e) {
	// catch "Unable to retrieve AudioTrack pointer for stop()" exception
	loge("exception trying to stop media player");
	}
	mMediaPlayer = null;
	}

	// Stop vibrator
	mVibrator.cancel();
	} else if (mState == STATE_SPEAKING && mTts != null) {
	try {
	mTts.stop();
	} catch (IllegalStateException e) {
	// catch "Unable to retrieve AudioTrack pointer for stop()" exception
	loge("exception trying to stop text-to-speech");
	}
	}
	mState = STATE_IDLE;
	}

	/**
	* Set AudioAttributes for mMediaPlayer. Replacement of deprecated
	* mMediaPlayer.setAudioStreamType.
	*/
	private void setAlertAudioAttributes() {
	AudioAttributes.Builder builder = new AudioAttributes.Builder();

	builder.setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION);
	builder.setUsage(AudioAttributes.USAGE_ALARM);
	if (mUseFullVolume) {
	// Set FLAG_BYPASS_INTERRUPTION_POLICY so that it still enables
	// audio in DnD mode (except total silence DnD mode).
	builder.setFlags(AudioAttributes.FLAG_BYPASS_INTERRUPTION_POLICY);
	}

	mMediaPlayer.setAudioAttributes(builder.build());
	}

	/**
	* Set volume for alerts.
	*/
	private void setAlertVolume() {
	if (mTelephonyManager.getCallState() != TelephonyManager.CALL_STATE_IDLE
	\|\| isOnEarphone()) {
	// If we are in a call, play the alert
	// sound at a low volume to not disrupt the call.
	log("in call: reducing volume");
	mMediaPlayer.setVolume(IN_CALL_VOLUME);
	} else if (mUseFullVolume) {
	// If use_full_volume is configured,
	// we overwrite volume setting of STREAM_ALARM to full, play at
	// max possible volume, and reset it after it's finished.
	setAlarmStreamVolumeToFull();
	}
	}

	private boolean isOnEarphone() {
	AudioDeviceInfo[] deviceList = mAudioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);

	for (AudioDeviceInfo devInfo : deviceList) {
	int type = devInfo.getType();
	if (type == AudioDeviceInfo.TYPE_WIRED_HEADSET
	\|\| type == AudioDeviceInfo.TYPE_WIRED_HEADPHONES
	\|\| type == AudioDeviceInfo.TYPE_BLUETOOTH_SCO
	\|\| type == AudioDeviceInfo.TYPE_BLUETOOTH_A2DP) {
	return true;
	}
	}

	return false;
	}

	/**
	* Set volume of STREAM_ALARM to full.
	*/
	private void setAlarmStreamVolumeToFull() {
	log("setting alarm volume to full for cell broadcast alerts.");
	mUserSetAlarmVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_ALARM);
	mResetAlarmVolumeNeeded = true;
	mAudioManager.setStreamVolume(AudioManager.STREAM_ALARM,
	mAudioManager.getStreamMaxVolume(AudioManager.STREAM_ALARM),
	0);
	}

	/**
	* Reset volume of STREAM_ALARM, if needed.
	*/
	private void resetAlarmStreamVolume() {
	if (mResetAlarmVolumeNeeded) {
	log("resetting alarm volume to back to " + mUserSetAlarmVolume);
	mAudioManager.setStreamVolume(AudioManager.STREAM_ALARM, mUserSetAlarmVolume, 0);
	mResetAlarmVolumeNeeded = false;
	}
	}

	private static void log(String msg) {
	Log.d(TAG, msg);
	}

	private static void loge(String msg) {
	Log.e(TAG, msg);
	}
	}