Hello!

hello, Grigore!

how can I help you today?

I'm having a hard time with AlarmManager

you and everyone else :-)

I'm trying to set a reminder, but I guess it's too often for the Android OS

Sometimes it works sometimes it doesn't

the "repeating" methods have a minimum repeat interval of 15 minutes, if I recall correctly

I've read about this yesterday in your book, they seem to work fine while app is in foreground

also, Doze mode and related power management stuff may cause alarms to be delayed

but doze mode delays them

yes

But how does whatsapp always "wake up" the screen?

WhatsApp is almost certainly not using AlarmManager

I would expect them to be using Firebase Cloud Messaging (FCM), on Google Play ecosystem devices

I get some notifications that even on Android 11 wake up my device

Yes, I read something about that, they might use FCM

So I need a 1 minute reminder no matter the doze mode.. what should I do? switch to FCM?

It's killing me D:

you need to do something every minute? you will need to be in the foreground

It's a reminder, user can set it to 1 min, 2, 3 .. or 10

or at least have a foreground service

is this repeating, or is this a one-off event?

repeating

a notification should pop up every x minutes

and update it's content

that is bad for the battery, which is why Android pretty much stops it from happening

yes... I understand that but gotta do it more or less

then I don't know what to tell you

there is simply no way to do that reliably over an extended period of time

not even with a foreground service?

I guess keeping the app in the foreground with the screen unlocked could allow me to do that, right?

you are welcome to try a foreground service, a partial WakeLock, and ScheduledExecutorService for the periodic timing

many device manufacturers, particularly from China, will still interfere with your operatino

er, operation

Doze mode will break it on the rest

so, if you are looking to do this for a short period of time (every few minutes for an hour), you might be able to get away with that

after that, reliability will decline

could some kind of refresh be implemented?

or it wouldn't matter?

I am uncertain what you mean by "refresh" in this context

maybe restart the foreground service

if your foreground service is not running, your code to restart the foreground service also will not be running

if the user interacts with the phone every few minutes, in response to your notifications, that will disable Doze mode, which is based on user inactivity

sounds like an impossible task

users have screamed very loudly over the years that they want longer battery life and fewer apps pinging them with notifications

your app appears to runs counter to those user desires

(er, "run counter")

Android is aiming to satisfy users in general, at the cost of breaking certain possible types of apps

now, if this is for custom hardware, you could modify Android on that hardware to allow for your app to bypass these restrictions

but if your app is to be deployed on ordinary consumer phones and tablets... you are going to have problems

does this imply rooting the device?

oh custom hardware.. no, that's not the case

yeah, I was implying a custom build of the Android OS

that you would be putting on your own hardware

and if that's not the case... I do not know what to tell you

no, that's not the case

what about the phone's settings?

you can ask the user to opt your app out of some of the battery optimization effects

or rooting?

users do not have to do this

there may be possibilities of bypassing the restrictions on a rooted device, but that is way outside my area of expertise

and users may not want to root the device

hm

well, thank you, Mark :)

I'm going to read some more on the things you specified

sorry I do not have better answers for you... the "War on Background Processing", as I have called it, has been going on for about six years

I'll let you know if I come up with a solution

don't worry, I am aware that my app is trying the opposite

and that there are a lot of custom android OS

like the huawei one, the samsung one etc

Huawei, Xiaomi, Oppo, and similar firms are even more aggressive than Google is regarding power management

a solution that works on a Samsung might not work on devices from those manufacturers

great news! haha

yes, I've noticed that

but sometimes even FCM notifications won't wake up the device

they have to be "high-priority", and on newer versions of Android, effectively they are throttled in terms of waking up the device

I presume that too many developers were trying to use FCM for... ummm... the sort of thing that you are trying to do :-)

I still don't get how whatsapp is doing this

I do not use it, but I would be astounded if they are trying to send high-priority FCM messages every minute

plus, bear in mind that WhatsApp/Facebook is slightly larger than you or I

they can strike deals with manufacturers for preferential behavior

that's right, they don't send notifications every minute

I've also thought about "super permissions" for big apps

in particular, pre-installed apps routinely can do things that ordinary user-installed apps cannot

that makes sense

another advantage that a WhatsApp has is a large engineering department

they can have a team focused just on dealing with this issue, finding what amounts to security exploits to bypass limitations

so, aiming for WhatsApp-level results, for most firms, is unrealistic

doze mode turns on when there is no user interaction right?

correct

I think there is an hour before it starts to have an effect

soo if app is in foreground and the phone will not lock

does that mean there is interaction?

roughly speaking, if the screen is on, Doze mode should not take effect

disabled screen lock and/or developer options with the stay awake while charging option enabled

I do not know if the screen lock itself affects Doze mode, though it could

but, yes, the "stay awake" developer option, or a full WakeLock, would keep the screen on

in those cases, Android assumes you have a good reason for that, such as playing a video

of course, having the screen on all the time is bad for the device

(battery, screen burn-in, etc.)

yes, but there are some trades off if you want 1 minute notifications

well, bear in mind that the user gets a vote, assuming that the app is being distributed to ordinary people

that won't be a problem

ah, OK

I mean this reminder is one of the "core" functionality of the app

oh

sorry for not mentioning this plot twist earlier

well, you are certainly welcome to try a full WakeLock and see how your app behaves

bear in mind that you need a running process for that, so you would want to go the foreground service route

I'll have a read on these

and for the repeating task should I use Handler?

I would use ScheduledExecutorService

despite the name, it is unrelated to an Android service

but it is a nice option for in-process periodic work when you do not care about the main application thread

hm I see that this could "beep every ten seconds for an hour"

might be what I need

with ScheduledExecutorService, the "every ten seconds" part is easy

"for an hour" is where you are trying to defeat Doze mode and manufacturer-specific power management

I'm going to try that, worth a try

thank you, Mark! Hopefully, I'll come back with a working solution

I wish you luck!

this chat will be archived, right?

yes, the transcript will appear on https://commonsware.com/office-hours/ shortly after the end of the chat

(basically, as soon as I upload it!)

great! it's a great feature so I won't have to printscreen all of this :D

and that is a wrap for today's chat

the next one is Saturday at 4pm US Eastern

have a pleasant day!