Computer Network Router User Manual

CHAPTER 8
Newton Services
Alarms 8-5
The Snooze button is optional. Your application can use a plain notification
alert without a Snooze button (see “Notification Alerts” on page 2-17) or no
notification alert at all.
Unacknowledged Alarms 8
Your application does not have to do anything to handle alarms that a user
does not acknowledge. If a user is away from his or her Newton when an
alarm goes off and the Newton goes back to sleep before the user returns, the
user won’t know the alarm went off until powering up the Newton again.
The Newton system’s Persistent Alarms user preference solves this problem.
When this preference is enabled, the system reschedules alarms until the user
acknowledges them. To conserve battery power, the length of time between
reappearances of a particular alarm increases in proportion to the number of
times it has gone unacknowledged.
Alarm Etiquette 8
Every application should schedule and use alarms in a way that does not
hamper the activities of other applications on the same Newton. Storage is
one concern, since each alarm uses internal storage space. You don’t have to
limit your application to one alarm, but scheduling a daily wake-up alarm
for the next year by creating 365 different alarms would use up an excessive
amount of internal storage. Exercise reasonable judgment when creating
multiple alarms.
Actions taken besides displaying a notification alert should be brief. If your
alarm initiates a time-consuming process, it may delay the execution of other
alarms set to go off at approximately the same time.
Note that your application may not be open when its alarm executes. In fact,
your application may not even be installed. If your application’s alarms aren’t
useful when it isn’t installed, it should remove them when a user removes it
(for example by removing the card it’s on). There is no point in wasting space
with useless alarms that display notification messages such as “Sorry, this
alarm can’t execute because the application isn’t installed.”