I have created an accessibility service for my app where it would detect of the current outgoing call is answered or not but now i want create a callback function to my activity when the call is answered.
I have found some code to make callbacks from service in below links -
Callback from Service
RESTFul API
but i cant figure out a way to do that with my accessibility service, as i am not starting the service, android is, so there is no way to pass an object to the service.
If anyone can help please share.
Your service and your activity are separate processes. They cannot communicate directly. You should look into BroadcastReceiver. Note, though, that the user would have had to start your activity and have it running in the background. If the system decides it is low on memory and kills your activity completely, there is nothing you can do. You will not reliably get this broadcast with your activity in the background. You could try starting a background process from your activity for the sake of finding this event and storing the results somewhere for future consumption. Depends of course on your use case.
Related
My application currently has two activities: a splash activity which displays the app logo and loads the user’s data from a remote database, and then the main activity that houses all my fragments. I’ve reached a bit of an impasse right now with notifications. I’m using FCM to deliver the notifications and have that working fine, but don’t really know what to do with the pending intents of the notifications. If the app is closed, I don’t want it to launch the main activity since I load the data from the DB in the splash activity. Thus the main activity would have missing data (it currently crashes due to null pointer exceptions everywhere). But if the app is still running, I don’t want the splash screen to be launched again. Is there some type of way to have a conditional intent baked into the notification?
Alternatively, is this just bad practice to do what I’m doing with launching the activities from the notifications? I’m by no means an android expert so there might indeed be a better way. I would prefer to keep my current activity flow however where the splash screen is responsible for the initial loading of data. I was hoping there was some way to just broadcast a message on the click of the notification and if any activities have an active listener then it would just consume that data.
The solution I have come up with is to have a single activity whose sole purpose is to process notifications and then pass them to the appropriate activity either through a new intent (if app is terminated) or through a broadcast (if app is resumed). Not sure if this is bad practice (would appreciate anyone telling me if this violates any type of software principle).
It's working like a charm so far and is honestly really nice to have all that logic in one activity anyway - all the service has to do is pass in the data from the notification and the action and the activity does the rest.
I'm struggling to decide which class to use, Activity or Service.
My application is complicated so I will use another example. A timer.
I would like to create an application that start to count the seconds when I open the application and keep counting even when I click the back button.
When I back to the application it will have a gui that show me the time.
So the gui I guess would be the activity and the counting method would be on the service.. but how do I manage that system?how they will be communicating? how can I do that?
You can use BroadcastReceivers and send broadcasts that your activity will be listening to, or you can use Messenger to send messages from the service to the activity
they can communicate with intents, or via shared storage, or content providers, ...
I want to send gps cordinates to a web service whenever the gps position on the phone gets updated.
Should i create a class that extends AsyncTask that sends the data to the webservice from the onLocationChanged event? Or do you guys suggest something else?
I started coding apps yesterday, so please tell me if im on the right track. Thanks
Yes, I think this would be the right approach. Extend AsyncTask and in doInBackground() make the POST/PUT to your web server.
Another approach may be to use a SocketConnection, but this will still have to be operated in a background thread, and may add overhead, to thread Socket disconnection etc.
Just be sure to unregister your BroadcastReceiver in onPause and also handle your AsyncTasks to get cancelled when a new one will be executed, or the Activity stopped... etc, depending on your application needs.
If you would also like to send the location while your app is in background you should consider implementing a Service.
I recommend the IntentService mechanism.
This has a lot of uses and is often overlooked by many Android developers.
I have been developing Android application that use Activity with "download" button and Service for executing downloading in the background. And I have following task: to show message about downloading if application is currently displayed. How can I detect it? Is there standard Android OS functions for it? Thank you.
You can do this at the activity level, not for the application as a whole. Check out the description of the activity lifecycle. (Also see "Managing the Activity Lifecycle" in the Activities framework topic.) When your activity becomes visible, the framework will call it's onStart() method. When the user can interact with the activity, the framework will call the onResume() method. You can override one of these to know when your activity is showing or actually interacting with the user.
Note that, as described in the documentation, things work a little differently starting in Honeycomb (3.0).
The basic method is to use Broadcast receiver to share information between a service and an application. If your requirement is to update the status/progress of download on the main activity, you can use it.
Here is a simple tutorial about how to share information between a service and an activity. You can update the progress of download. It works for the activity that is currently running.
To check for it as the activity starts, you should override the onCreate, onStart() or onResume() functions.
Also there is a very neat solution presented in another question and i recommend that you should try to use that. It involves extending the Application class to store the information, and use its instance to check for updates. See this
I have this basic design in mind:
A main activity will offer a choice of sub activities and also create a Bluetooth service.
The Bluetooth service will reads and buffer live data from a Bluetooth connected device. Enough data , at a fast enough rate (100 to 1000 sps ) so that I don't think it is realistic to use Intents or broadcasting
The sub activities will simply be displaying the same received data but in different way.
Each sub activities will also the user to interact with the data in a different way.
I really prefer that the Bluetooth service is agnostic of the Activity/View onto which the data gets presented.
I'd be willing to 'register' a bunch a 'destination' (which would really be activities) to which 'cooked' data would be sent to. I didn't quite get how to 'register' anything from starting an activity.
How do I pass, for example, a reference to my service to each of those activities? Or it might be the other way around; how do I register each activity to the running service.
Having a C/C++ background, I realize this might not be a good approach in Java.
Thank you.
Ideally this not NOT the best way to approach it. Specifically android is a system that bases its services on passing information via intents from activity to activity, activity to service, service to service.
The way I would approach this would involving having an app on the phone that would be communicating with a service. Specifically the app would receive the data from the service. However; in order to allow the activity to listen to it, you could have the service broadcast a message saying there is new information, and have this activity intercept it. When the service is building this message, you could have information passed via an intent (extra) to the activity. The activity would have a Broadcast Listener inside of it that specifically updates information relative to that service inside of that activity.
And perhaps to keep information from being lost, throw messages into a stack and read it accordingly until its empty (This is assuming you get ton of information)
These links should help
Broadcast Reciever
http://thinkandroid.wordpress.com/2010/02/02/custom-intents-and-broadcasting-with-receivers/
Services
http://developer.android.com/reference/android/app/Service.html
http://marakana.com/forums/android/examples/60.html