How to call a function continuously in background in an Android app? - java

I know it might seem a repeated question, but I want to call a method to report geolocation position every minute as long as the application is open. Other answers recommended using CountDownTimer class. Is there a better way in Android to repeatedly call a function in background?

No idea who suggested a count down timer, but in Android you can use Services namely the Background Service. See here

You could consider something like an AlarmManager - which will run periodically, i.e. every minute to execute an Intent
The risk you run, if something is continuously running, is it will be shut down by the OS.
Alternatively, if you're checking network connectivity etc then you can look into BroadCast receivers - and there's no need to run continuously in the background.

It depends on how you are getting the location. If you use play services you can take advantage of the LocationRequest class. For more information about how to use play services to get the location, please have a look at this training put together by Google.
Hope this helps.

Related

Make Chathead bubble run forever in android

Hi I am trying to make a chathead bubble, like the one facebook has, for an app in android studio. I have been able to successfully display the bubble using Overlay and make it a service which continues to run even after the app is closed (not killed). However when I open another app or if I dont use my phone for more than 10 minutes, the chathead bubble disappears, unlike Facebook's bubble. How can I go about making the bubble display on the home screen and other apps for a longer period of time(potentially forever)?
For context, I used https://www.androhub.com/android-floating-widget-like-facebook-messenger-chat-head/ to make the bubble, using a View and a Service.
Thanks in advance
Your app's service will get killed by the android system to save battery. There is no exact and easy way to do that. You have to implement multiple methods to do that.
Use Foreground Service(You may have already doing this but just in case if not.)
Ask for permission to restrict Battery Optimization.
In some devices like Xiaomi and Vivo, you need special permission to always run in the background ask for that.
Ask the user to lock the app in recent tab so it won't get killed by the system.
If you are implementing the service, override onStartCommand() and return START_STICKY as the result. It will tell the system that even if it will want to kill your service due to low memory, it should re-create it as soon as memory will be back to normal.
If you are not sure 1st approach will work - you'll have to use AlarmManager http://developer.android.com/reference/android/app/AlarmManager.html . That is a system service, which will execute actions when you'll tell, for example periodically. That will ensure that if your service will be terminated, or even the whole process will die(for example with force close) - it will be 100% restarted by AlarmManager.

Is this the correct situation to use a service?

I'm building a fairly simple data tracking app. Using a runnable, every 5 seconds my app checks how much data the user has consumed and updates the UI.
The app works well, and the runnable keeps going even when the app is not in the foreground, but when the app is closed, it stops.
I've never used a service before, and after reading some documentation, I'm still unsure if that's what I need. I need to be able to update the UI, and depending on the data amount, start an asynctask to update a server.
Right now this part is happening from the runnable, but from what I've read about services, it seems like interacting with the UI is difficult.
I was originally hoping that I could somehow just prevent the app from ever being killed. It's going to be used on a private system, so there's no concern of the user 'getting annoyed' that the app can't be closed, but I can't figure out how to pull it off.
Thanks in advance for any information!
Note: I didn't post any code because I didn't think it was relevant here, but I'd be happy to upon request.
Is this the correct situation to use a service?
Yes.
from what I've read about services, it seems like interacting with the UI is difficult.
It's not that hard. The easiest solution would be to use an EventBus.
Another solution without a library: The Activity binds to the Service in onCreate. The Service returns a Binder. The Activity passes a Listener to that Binder. The Service calls the listener as soon as the UI needs to be updated.

Detect package launch android

I need to detect if an application is launched and I've read that there's nothing in APIs to achieve this.
Someone suggested to give the app the permissions to read logs and keep polling them, but this solution isn't working since JB.
I also found that since I just need to know if the on top application changes I could do the following:
ActivityManager am = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
String str = ((ActivityManager.RunningTaskInfo)am.getRunningTasks(1).get(0)).topActivity.getPackageName();
But I need to know which way would be the best one to do this continuous polling, and - of course - if there is any other way to do this.
You could use accessibility service
http://developer.android.com/reference/android/view/accessibility/AccessibilityEvent.html and caputure window change event
As apps are used by people and people need time to read the info on the screen, it is not usual that the foreground app is visible for less than several seconds.
If you are trying to detect what apps the user has launched, then having a background service that polls every second or so polls the list in the way you indicate, then it should work fine and not deplete the battery either as the polling will be stopped as soon as the system goes to sleep.

PopUp-Window as background task Android Application

i've a question for a feature, i want to implement.
I know some applications, like whatsapp, gmail or others, which run in background and notify the user, if something is received...
i'd like to do the same with my application. i've a http-network-connection and want to notify the user, even if he hasn't the application started. is something like this possible?
Is it possible, that a PopUp-Window, like receiving a sms, appears?
(if not, the notify-way in a titlebar is enough)
i've no idea, what i should google or where i can find help
Thank you a lot!
Edit: I found another very cool framework which deals with notifications. Have a loot at: https://www.parse.com/tutorials/android-push-notifications
You should take a look into Services. You can have the http connection listening in it. For the notification I'd use the NotificationManager class. A notification is much more less intrusive than a pop-up.
Hope that helps
Google Cloud Messaging will definitely help you.
If your server can instantiate this 'action' or 'event', by all means don't try to pull data periodically, coz that brings extra complexity to your app and also battery drain to your users.
But if you really, truly, badly need this behavior, you can instantiate a Service from your app's process. This can be done from many places, like your main activity or some other user action, or even from a broadcast listener. For example, our app has some parallel work to do, so we pass this to a service and that service is initiated by a broadcast listener listening for phone events like a phone call or sms.
On the other hand, just like the main activity of your app, your background service can be killed arbitrarily by the operating system any time. So you shouldn't depend on it running forever. You should have ways to check if that is still working in the background. Check alarm events or any other relevant broadcast listeners.

Android application executing code in the background

A very simple question:
I know that Android applications run in the background when they are closed. Is it possible for my application to keep working while it is in the background? For example, maintaining a timer in the application to automatically perform a function every hour?
Thanks!
Use services for doing tasks in background. more info is here http://developer.android.com/guide/topics/fundamentals/services.html.
An alarm service should meet your needs; here's an example.
To run things in the background (or outside of the main application thread) there are a few options. To do something very quick in the background the easiest way is to use an AsyncTask. It sounds like you are wanting to implement a bit more than an AsyncTask would handle though. For more longterm tasks that you want to run behind the scenes you probably want a Service.
You can have services that run, do what they are supposed to do and then exit, and you can have ones that keep running. Services have a lot of depth. You could use the AlarmService that is linked above by another user, however another approach would be to just make a simple service and use a TimerTask http://developer.android.com/reference/java/util/TimerTask.htm
Remember though, when you are doing things in the Service, they will be being done on the Main Thread, which could slow down other programs, so any logic over long periods of time needs to be accomplished in an AsyncTask.

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