Using AlarmManager.RTC and phone still can be woken up with back button
<p>I'm experimenting with an App Widget that does some animation regarding some phone state. I've set up a <code>RTC</code> type repeating <code>AlarmManager</code>, <code>intent-filter</code> and a <code>PendingIntent</code> to update it on a per second basis. Now when I put the widget on the launcher screen it works well. However, when the phone goes black (while running the widget) it can be woken up by pressing the back button. It tells me that it isn't really sleeping. (It behaves like in <code>PARTIAL_WAKE_LOCK</code>.) After removal of the widget the phone can go to sleep just like it should. I'm using <code>AlarmManager.RTC</code> to be able to stop the update when phone is in sleep mode to save battery. But it looks like that the phone is not going to sleep while the widget is running because I can resume it with the back button.</p>

<p>Is that really the case? Why is it not going to sleep? How can I let the phone go to sleep and stop the update at the same time then?</p>

<p>Please help me, thx!</p>

<p>Edit:
Interesting addition: If I set the <code>AlarmManager</code> interval to 3000 (from 1000) the phone goes to sleep well. Why is this? Why does sleep depends on repeat interval? Seems like there's a timeout for something. Is it the timeout which takes place when you can still resume your phone bythe back button after dimming and after a timeout just by the power button?</p>
