I want to write a service for Android platform that is notified when the current foreground activity changes.
Basically the service should do some tasks only when the top activity changes.
Is there any way to subscribe and to be notified when this kind of event occurs ?
Or there is no possibility and the service should poll from time to time the list of running activities and to check what is the foreground activity ?Not preferable solution...
AFAIK there are two ways to do that.
Start a service and monitor the Activity Stack, you might check it here
Use an Accessibility Service, you could find a solution here
You should bind every activity to the service and you will know which activity is running.
try this:
List runningTaskInfos=actvityManager.getRunningTasks(1).get(i).topActivity .getPackageName();
this method will give info of activity's package name which is in foreground..............
Related
Am having an activity that will start service, service will download something from internet and i have to update activity UI.
but consider below cases
If my activity is alive i have to update activity UI without broadcast receiver, What is the best way to do this.?
If my activity is not alive and when it comes alive/foreground then i have to update UI with service result, How to do this.? (without saving into DB)
Let me drop my suggestions point by point,
Yes you can achieve it by EventBus (or) interface. Coming to eventbus, it is similar to broad cast receiver.
When the activity is not alive, you are fetching the data and when coming to alive you had to update the UI. In order to do that somehow you had to save the value somewhere either internally or externally (OR) you had to fetch the values from the internet whenever the activity comes to alive.
How to detect user activity/inactivity in android service/background application - from same or other applications?
I want to know that user stop touching screen and not busy with another activity to show notifiation popup. Not sure is there no other method than use AccessibilityService.
One of the ways is to know that from reading the Android logs
Use a boot receiver to setup the AlarmManager (and of course also check to start the polling from your main Activity too, for the case when your app is installed and the system is not booted) and have the AlarmManager send an Intent for another receiver.
I think they answered it in this question to do what you are looking for:
android: running a background task using AlarmManager
Define a interface in activity and service.
in oncreate of activity set reference to activity in service method.
Now you have activity reference for entire service lifetime.
another way to do this is, application class, same application class is shared by activity and service, so you can both of these from each other using application class.
If you want see from applications then use broadcastreceivers that is the only wau
My application consists of one activity which creates a service. I want the service to be keep running as long as application is running. I know:
It is not guaranteed as Android system can kill activity in low memory conditions and if activity is in background.
The service can be stopped (and killed) by system.
If I bind service to the activity, the activity would get notification in case service is being stopped or started. However, the service may stop running if activity goes in background (onStop()). Please correct me if I am wrong here.
If I bind to service in onResume() of activity and unbind() in onStop(), it might happen that service stops running when my application goes in background. If I bind in onCreate() and unbind() in onDestroy() of activity, would it mean that my activity will keep getting notification from service even when in background.
What is the best way to keep service running and get notification from service to Activity as long as application is running. Please note that there is just one activity in the application so sending activity in background means application goes in background.
Thanks
true
true, but its more rare if us use startForeground()
The service usually won't stop until all activities have unbound. But when the last has, it will. So u can prevent the service from dieing when going to background, if you only unbind in onPause if isFinishing() == true.
see 3.
I personally like to set up a Handler in the Activity and send Messages to it from the service.
If you are binding a Service to your Activity. It simply means that you need service to run as long as your activity is running. If you do not need to bind Service with activity or you do not need to update your UI while your Service is running. you must not bind your Service to your Activity. In this case, for different actions done by Service you can notify user using Android Notifications. Like notifying user that xx download has been completed.
It totally depends upon your purpose that you want to achieve from Service.
if you can use IntentService for your application, you can pass data to the service through an Intent. results can be passed back to the Activity through a ResultReceiver
If you bind your Service to your unique Activity, you'll have it alive as long as the Activity is not terminated or the service isn't unbound. Just bind it on the onCreate() and let it get unbound when stopping your activity (no need to do anything).
You can create a Listener interface within your service, that you'll implement in the Activity, so you can send those notifications from the Service to the Activity. You'll find suitable example and information about this if Googling.
I have the following situation: A service is running in the background of my application and regularly receives UDP packets. It uses an instance of my HandleMessageAgent class which analyses every message and shall start a new activity if necessary.
I would like to perform the following task: No matter which activity is in the front (as long as the service is running) I would like to inform the user about an incoming message under certain circumstances. I also need to update the information regularly as long as it is valid. Afterwards it should be closed automatically.
At first I thought about using a Dialog, but I think I cannot use it when the activity is not visible. Therefore I decided to use an activity, as it can be started from a service all the time.
I want to start the activity within the HandleMessageAgent object (in a method). My problem is, that I do not know how I can define an Intent to start an activity within an object, as the Context is not clear to me.
Is there a more elegant way to perform this task? Or can anybody help me with starting an activity from an object method within a service? Thank you!
There are two situations to consider:
When your service need to notify user your activities are not active, because some other app is active. In this case you should notify user via a system-preferred way: Android Notifications. You should not forcefully show dialogs or activities if user is using some other app. That's what notifications are for.
If one of your activities is active (no matter which) then your service should send a broadcast and interested activities should listen for it and act upon it. That way your service will not depend upon specific activity and will not need to keep track which activities are active at the moment the notification must be shown.
You can make your object Parcelable and add it to the Intent that will start the Activity.
Or you can put it in a subclass of Application because that instance is shared between your activities and your services (as long as they're in the same process)
You might need the "START_NEW_TASK" flag on the Intent
I have a service which has to monitor which application is in the foreground and based on the application do some functionality.
I can get the list of foreground applications, using ActivityManager.getRunningAppProcesses().
But with this I cannot monitor when the foreground application changes.
ex. when Application 1 which was foreground goes to background and a new Application 2 comes to foreground, the service should be notified about this.
Are there any Broadcasting happening in Android, so that my service can register to that and when there is a change in foreground application, the service gets a notification and can do the functionality as required.
I do not want to do any changes in the Applications...
Any possibilities please suggest...
Then a simple solution is Create static variable of type Context() in some Class and in all onResume() methods activities initialize it with their Instances.. and check it in service using if conditon and carry on..