Pro Android with Kotlin

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CHAPTER 8: APIs
Table 8-5. Auxiliary AlarmManager Methods
Method
Description
cancel(operation: PendingIntent) : Unit
This removes any alarms with a matching intent.
cancel(listener: AlarmManager.
OnAlarmListener): Unit
This removes any alarm scheduled to be delivered to 
the given AlarmManager.OnAlarmListener.
getNextAlarmClock() : AlarmManager.
AlarmClockInfo
This gets information about the next alarm clock 
currently scheduled.
setTime(long millis): Unit
This sets the system wall clock time, UTC
(milliseconds since January 1, 1970, 00:00:00).
setTimeZone(String timeZone): Unit
This sets the system’s persistent default time zone.
Loaders
Loaders are for loading data in the background. The main usage pattern is as follows:
1. The need to load data in a presumably time-consuming process 
arises, either in the UI thread after, for example, clicking a button 
or from any other place inside the code. Because the loading is 
expected to take some time, you want to have the loading happen in 
the background, not disturbing the UI, for example.
2. You get the LoaderManager from the context. From within activities, in 
Kotlin you just use the pseudo-getter loaderManager.
3. You implement and provide a subclass of LoaderManager.
LoaderCallbacks. The main responsibility of this class consists of 
constructing an android.content.Loader and providing loading state 
callback functions.
4. You call init(...) on the LoaderManager and pass the callback’s 
implementation.
5. You react on callback events.
Looking at the online API documentation for the Loader framework, two points are worth 
mentioning.

Almost all over the description and for all examples (and also for almost 
all examples you can find on the Web), using the compatibility libraries 
for the Loader framework classes is suggested. This is for backward 
compatibility. The truth is, you don’t have to do that. The Loader 
framework has been around for quite a while, since API level 11 to be 
precise, and since you might not care about the less than 1 percent in-
use versions below API 11, the need to use the compatibility libraries for 
Loader framework classes might not be too high.

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