Simple Analysis of Android alarmclock alarm Application

Author: Xu jianxiang (netpirate@gmail.com)
Date: 2010/01/06
Web: http://www.anymobile.org

1/set a alarm clock
1.1 update alarms. db
1.2 update com. android. alarmclock_preferences.xml
1.3 update Settings. System. NEXT_ALARM_FORMATTED for status bar
1.4 set Kernel RTC alarm or send a message if no driver

Flow:
Com. android. alarmclock. AlarmClock. onCreate ()-> SetAlarm. onPreferenceTreeClick ()-> SetAlarm. saveAlarm ()->
Alarm. setAlarm ()-> Alarm. setNextAlert ()-> Alarm. enableAlert (ALARM_ALERT_ACTION)/saveNextAlarm (Settings. System. NEXT_ALARM_FORMATTED)->
Android. app. AlarmManager. set ()-> AlarmManagerService. set ()-> AlarmManagerService. setRepeating-> AlarmManagerService. setLocked ()->
Android. app. IAlarmManager. set ()-> RTC. save () // dev/alarms

2/play a clarm clock

Flow:
RTC (WAKEUP)-> AlarmReceiver. onReceive (ALARM_ALERT_ACTION)-> AlarmAlert. onCreate ()->
AlarmAlertWakeLock. acquire ()/KeyguardManager. newKeyguardLock (). disableKeyguard ()->
AlarmKlaxon. postPlay ()-> AlarmKlaxon. KillerCallback (). onKilled ()-> AlarmAlert. dismiss ()->
AlarmAlertWakeLock. release ()/KeyguardManager. newKeyguardLock (). reenableKeyguard ()

Some description:

/**
* Days of week coded as single int, convenient for DB storage:
*
* 0x00: no day
* 0x01: Monday
* 0x02: Tuesday
* 0x04: Wednesday
* 0x08: Thursday
* 0x10: Friday
* 0x20: Saturday
* 0x40: Sunday
*/

/**
* Alarm Type
*
* Elapsed_realtime alarm time in time since boot, including sleep, this alarm does not wake the device up.
* Elapsed_realtime_wakeup alarm time in time since boot, including sleep, this alarm will wake up the device when it goes off.
* RTC Alarm time in wall clock time in UTC, This alarm does not wake the device up.
* RTC_WAKEUP Alarm time in wall clock time in UTC, This alarm will wake up the device when it goes off.
*/

Db example:

# Cat/data/com. android. alarmclock/shared_prefs/com. android. alarmclock_preferences.xml

1 <? Xml version = '1. 0' encoding = 'utf-8' standalone = 'Yes'?>
2 <map>
3 <string name = "label"> alarm </string>
4 <boolean name = "vibrate" value = "true"/>
5 <boolean name = "on" value = "true"/>
6 </map>

# Sqlite3/data/com. android. alarmclock/databases/alarms. db
SQLite version 3.5.9
Enter ". help" for instructions
Sqlite>. tables
Alarms android_metadata
Sqlite>. schema alarms
Create table alarms (_ id integer primary key, hour INTEGER, minutes INTEGER, daysofweek INTEGER, alarmtime INTEGER, enabled INTEGER, vibrate INTEGER, message TEXT, alert TEXT );
SQLite> select * From alarms;
1 | 7 | 0 | 127 | 0 | 0 | 1 |
2 | 8 | 30 | 31 | 1262766600000 | 1 | 1 | alert | content: // media/Internal/Audio/Media/21
3 | 9 | 0 | 0 | 0 | 0 | 1 |