Situation: We have more than 5 android applications which are modular (and really limited in terms of functionality) and each has it's own IntentService in which it gets data from internet and stores it locally.
Also one app is core/main app. Now I want, that each app updates its data during the night. I don't want to put code for alarm, receiver and other stuff into every app. I want that core app sets Alarm, and when alarm goes off, then core app calls all IntentServices of every app.
Question: How can I prevent that system goes to sleep during the execution of services?
One solution is that I use #CommonsWare implementation of WakefulServices in every every app instead of IntentService, but I don't really want to change code in all the apps. Is there any elegant way to solve this?
Thanks #CommonsWare your thoughts were really helpful.
So to conclude, solution is that every app implements WakefulIntentServices and then core app starts WakefulIntentServices of all the apps.
Related
I am writing a python app in kivy.
The idea is to allow the user to make notes of bookings for certain dates, and then the program should send them a notification on that day about the booking.
There's probably a simple way to do this, I am using plyer.
from plyer import notification
notification.notify(title="Kivy Notification",message="Plyer Up and Running!",app_name="Waentjies",app_icon="icon.png",timeout=10)
This works, I get a notification whenever I call that function, however, I can't find any way to send this notification while the app is not running, I do know that there are some other questions that seem to answer this question, but they don't, their simply to run a app in background, which I don't want to do, all I want is something like Clash of Clans notification when your troops are ready for battle, or Facebook's notification when somebody liked your post.
I think you should take a look at the Android AlarmManager. If this is what you need, here is an example for Kivy.
AlarmManager
This class provides access to the system alarm services. These allow you to schedule your application to be run at some point in the future. When an alarm goes off, the Intent that had been registered for it is broadcast by the system, automatically starting the target application if it is not already running.
On Android, I'm not sure how I would implement it without a background service.
The thing with background services is they also get killed when the application that started the process gets killed.
I know 2-3 ways to prevent that on Android, I consider it hack, but maybe it's a feature.
One is to use the START_STICKY flag. It's implemented in python-for-android, but it seems broken to me.
Another one is to use the a recent feature, setAutoRestartService(). It will make the service restart itself gracefully/programmatically on kill.
Bonus way use a BroadcastReceiver, but this is not implemented in p4a.
my knowledge of services in any operating system, is that they usually run in the background and perform whatever work they have to do.
but the first time I got familiarized with android services, I got confused.
it appears they only run when the application is working, and that for me, makes them no more then sophisticated threads.
do I have this all wrong? how do I make a service that runs when the application doesn't? (so that I can check for updates and create notifications for the user that will then lead him to the application if he chooses to open them).
does push notifications have anything to do with it?
Edit:
thank you guys for your answers so far.
my problem seems to be the fact that the service is only started officialy when the device is booted up. I do call startService when the app starts, but that doesn't seem to help. the service still dies when the app is turned off (unless it was booted)
also I never call stopService
If you are trying to implement a long running task that is performed in a (background) service, you have to start one or more threads within your service. So the service just gives you the opportunity to have an application context without having to have a user interface ;) you can consider it as a kind of container.
This page give you a nice overview about different thread approaches in Android. As you can see a service has not its own thread.
Anyway, in your case it seems that an AlarmManager is probably the better option. Running services for polling information all the time can be quite CPU and battery consuming (see this post for instance). So try to avoid having threads that run all the time.
If you can push information about updates from a server it's just fine. Check out Googles Cloud Messaging in this case.
Michael who commented on my question first was right in his comment about startService()
so it goes like this:
my receiver is only activated on boot, and uses an AlarmManager to
time the service to certain intervals.
what I did was to bind the activities to the service. if the service
was off and I binded it and unbinded it, then by the time the app was
terminated, there was nothing keeping it alive.
by simply making sure that the service was started properly with
startService if it is not already on, I managed to keep the service
alive at all times
also thanks to Trinimon who gave a very nice explanation on what
services are, and the importance of not overloading the CPU with
excessive polling. (which is kind of a trade off situation)
good luck to all :)
I'm looking for some timer alternative, since timer dies with app, is limited, and every timer launches own thread.
Sometimes I need to launch about 20-30 timers.
I need to set some event, in time, and when it comes display app screen. Is it possible?
This may or may not be possible depending upon your definition of "dies with app".
You can use AlarmManager to schedule PendingIntents to be invoked at specific times in the future. Those PendingIntents can launch activities. This will work if your app "dies" from ordinary causes.
However:
If the user force-closes your app via Settings, your alarms are unscheduled, and there is nothing you can do to stop this (nor do you have any alternative to AlarmManager that somehow survives this)
Please allow the user to determine whether or not you display an activity or raise a Notification at these times, as users may not necessarily appreciate having their game, navigation, video, or phone call interrupted by your activity.
You should use AlarmManager.
As CommonsWare says that there are some limitation of it, but that is ok, if an user force closes your application it means he doesn't want to use your application (any more or due to sort of memory)....
And I have a solution (but may be not the best), because you can not listen if user force closes your app, so one way is that you can re schedule your event on each start of your application. I know this is not a good solution but ..... we have no any other way yet
Here is a good example.
I did a search before asking so please don't tell me to do that.
I'm relatively new to Android so I get confused easily.
I'm making a simple app that changes the ringer volume according to time. For this purpose, I know I need a service that keeps running in the bg and monitor time. However, I really don't know how to approach this. I have the Professional Android Application Development book but haven't found anything that helps in there.
My question:
How to constantly check time without destroying the battery
If my code is needed (as proof of me actually working on this), I'll post.
You don't need a service. Use the AlarmManager class. Its like an alarm clock and it exactly what you need for this type of app.
need a service that keeps running in the bg and monitor time
No. Actually that's not how to do it. Services on android are different than your normal windows service/unix daemon. They should do their job and then stop themself until they get started again - to save battery.
You should start your service at a certain point in time by using the AlarmManager, it sends the launch intent to run the service. When the service is finished doing what it's supposed to do (change the rintone volume here), use Service.stopSelf() to kill it.
I'm implementing an background process that will update information my app uses.
I only want this process to update say once a day, if the process gets data newer than what it had before I want to present the user with a notification, exactly like twitter/gmail does.
I want the update process to run automatically, even when the main app is not open.
Is a Service the best way to go? I've been reading quite a bit about this, I figured a service running all the time for something that is only going to do work once a day seems a little overkill.
However I notice google run service for friendlocation and google+ services continuously on my nexus.
I've look into starting my service via the AlarmManager so its only started when required.
Some posts also suggest using the Handler class, I don't think this will work.
Just looking for the best practice here.
I figured a service running all the time for something that is only going to do work once a day seems a little overkill.
Absolutely.
I've look into starting my service via the AlarmManager so its only started when required.
This is the correct answer.
If you only want your code to be invoked if the device is on, implement an IntentService, do your work in its onHandleIntent(), and have AlarmManager start up the service on your desired schedule.
If you want your code to force the phone to wake up, you can do that, but you will need to use a _WAKEUP-style alarm, and you will probably want to look at my WakefulIntentService, designed to handle this pattern.