Pro Android with Kotlin

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CHAPTER 8: APIs
You can then issue alarms by various methods, as shown in Table 
8-4
. If for API levels 24 
or higher you choose to have a listener receive alarm events, the details about how to use 
the associated handlers are covered in Chapter 
10
. If instead you’re aiming at intents, all 
corresponding methods have a type:Int parameter with the following possible values:

AlarmManager.RTC_WAKEUP
The time parameter is wall clock time in UTC (milliseconds since 
January 1, 1970, 00:00:00); the device will be woken up if necessary.

AlarmManager.RTC
The time parameter is wall clock time in UTC (milliseconds since 
January 1, 1970, 00:00:00). If the device is asleep, the event will be 
discarded, and no alarm will be triggered.

AlarmManager.ELAPSED_REALTIME_WAKEUP
The time parameter is the time in milliseconds since the last boot, 
including sleep time. The device will be woken up if necessary

AlarmManager.ELAPSED_REALTIME
The time parameter is the time in milliseconds since the last boot, 
including the sleep time. If the device is asleep, the event will be 
discarded, and no alarm will be triggered.
Table 8-4. Issuing Alarms
Method
Description
set(type: Int, triggerAtMillis: Long, 
operation: PendingIntent): Unit
This schedules an alarm. An intent gets invoked 
and triggered according to the type, and the time 
parameter is provided. Starting with API level 19, 
alarm event delivery might be inexact to optimize 
system resources usage. Use one of the setExact 
methods if you need exact delivery.
set(type: Int, triggerAtMillis: Long, 
tag: String, listener: AlarmManager.
OnAlarmListener, targetHandler:
Handler): Unit
This requires API level 24 or higher. It is a direct 
callback version of set(Int, Long, PendingIntent). 
The Handler parameter can be null to invoke the 
listener on the app’s main looper. Otherwise, the 
call of the listener will be performed from inside the 
handler provided.
setAlarmClock(info: AlarmManager.
AlarmClockInfo, operation: 
PendingIntent): Unit
This requires API level 21 or higher. This schedules 
an alarm represented by an alarm clock. The alarm 
clock info object allows for adding an intent, which 
is able to describe the trigger. The system may 
choose to display relevant information about this 
alarm to the user. Other than that, this method is like 
setExact(Int, Long, PendingIntent) but implies the 
RTC_WAKEUP trigger type.
(continued)

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