Now, Your Friends Are AlarmedThe setAlarm() implementation tells AlarmManager to schedule a one-shot
alarm (rather than a recurring alarm), using the time-base of
SystemClock.elapsedRealtime(), to go off in period milliseconds from now,
invoking our PendingIntent at that point.
We now need to do the actual work itself. According to the protocol for
WakefulIntentService, we need to override a doWakefulWork() method, which
will be invoked inside a partial WakeLock every time the service is started.
For those that are actual polling Intents, we want to poll the Twitter
accounts, then schedule the next alarm:
@Override
protected void doWakefulWork(Intent i) {
if (i.getAction().equals(POLL_ACTION)) {
for (Account l : accounts.values()) {
poll(l);
}
}setAlarm(isBatteryLow.get()? POLL_PERIOD* 10 : POLL_PERIOD);
}You will recognize some of this functionality as mimicking the threadBody
Runnable that we are no longer using.
Note that while AlarmManager supports recurring alarms, since our polling
period may change based upon battery state, we are manually scheduling
successive alarms here.
We also need to cancel the outstanding alarm when the service is
destroyed:
@Override
public void onDestroy() {
super.onDestroy();alarm.cancel(pi);
unregisterReceiver(onBatteryChanged);
}Finally, WakefulIntentService requires a constructor, because IntentService
(supplied by Android) does. The WakefulIntentService's constructor takes a