diff options
Diffstat (limited to 'android/app/AlarmManager.java')
| -rw-r--r-- | android/app/AlarmManager.java | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/android/app/AlarmManager.java b/android/app/AlarmManager.java index 55f9e289..382719b4 100644 --- a/android/app/AlarmManager.java +++ b/android/app/AlarmManager.java @@ -568,9 +568,21 @@ public class AlarmManager { } /** - * Schedule an alarm that represents an alarm clock. + * Schedule an alarm that represents an alarm clock, which will be used to notify the user + * when it goes off. The expectation is that when this alarm triggers, the application will + * further wake up the device to tell the user about the alarm -- turning on the screen, + * playing a sound, vibrating, etc. As such, the system will typically also use the + * information supplied here to tell the user about this upcoming alarm if appropriate. * - * The system may choose to display information about this alarm to the user. + * <p>Due to the nature of this kind of alarm, similar to {@link #setExactAndAllowWhileIdle}, + * these alarms will be allowed to trigger even if the system is in a low-power idle + * (a.k.a. doze) mode. The system may also do some prep-work when it sees that such an + * alarm coming up, to reduce the amount of background work that could happen if this + * causes the device to fully wake up -- this is to avoid situations such as a large number + * of devices having an alarm set at the same time in the morning, all waking up at that + * time and suddenly swamping the network with pending background work. As such, these + * types of alarms can be extremely expensive on battery use and should only be used for + * their intended purpose.</p> * * <p> * This method is like {@link #setExact(int, long, PendingIntent)}, but implies @@ -783,9 +795,9 @@ public class AlarmManager { /** * Like {@link #set(int, long, PendingIntent)}, but this alarm will be allowed to execute - * even when the system is in low-power idle modes. This type of alarm must <b>only</b> - * be used for situations where it is actually required that the alarm go off while in - * idle -- a reasonable example would be for a calendar notification that should make a + * even when the system is in low-power idle (a.k.a. doze) modes. This type of alarm must + * <b>only</b> be used for situations where it is actually required that the alarm go off while + * in idle -- a reasonable example would be for a calendar notification that should make a * sound so the user is aware of it. When the alarm is dispatched, the app will also be * added to the system's temporary whitelist for approximately 10 seconds to allow that * application to acquire further wake locks in which to complete its work.</p> |