I have a service listening to some events from server.
A service has START_STICKY flag that makes him restart when it's killed by OS.
When service receive an event i have two scenarios.
First, if activity isn't killed i need to send result to local broadcast receiver and update UI.
Second, if it's killed by OS i want to recreate it and send data in bundle.
But i don't know how to recognize that android killed my activity.
onDestroy activity event doesn't come in this situation.
#Override
public void onComplete(CurrentOrdersResponse response) {
if (response == null) {
return;
}
boolean isActivityDestroyed = mPreferences.getBoolean(MainActivity.IS_MAIN_ACTIVITY_DESTROYED_PREF_KEY, false);
if (!isActivityDestroyed)
sendResult(response.getResJSONStr(), CURRENT_ORDERS_ACTION);
else {
Intent intent = new Intent(this, MainActivity.class);
intent.setAction(Intent.ACTION_VIEW);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtras(extras);
startActivity(intent);
}
int resCode = response.getResCode();
Log.i(LOG_TAG, "Service resCode" + " " + resCode);
}
It sounds like you are using LocalBroadcastManager. That's good. Its sendBroadcast() method returns a boolean indicating if a registered receiver was found. You can use that result to determine if your receiving activity (MainActivity) exists and has registered to receive the broadcast.
When your service has an event to send to MainActivity, first try to send the event using sendBroadcast(). If it returns true, your done. If it returns false, the activity is not registered and must be created using startActivity(), with the event passed as an extra, as shown in your posted code.
Related
I have a Service that scans for BLE devices. The Activity should show some data gathered by the Service.
A Receiver has been implemented, to be notified when the Bluetooth is enabled, so that we know when to start the Service.
If the Service is running, and the Activity is opened, it just executes bindService(). However, if the Service isn't running (because the Bluetooth is disabled), the App is opened and the Bluetooth is enabled, it won't bind because the binding process has already been skipped.
How can I be notified about the Service starting or automatically binding when started?
Thank you.
You can use the LocalBroadCastManager to send a broadCast from your service to your activity.
Helper to register for and send broadcasts of Intents to local objects within your process. This has a number of advantages over sending global broadcasts with sendBroadcast(Intent):
You can use localbroadcast reciever from your service.
In your service use these code
intent = new Intent("my-integer");
intent.putExtra("message",""+a);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
In your activity use this code
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Extract data included in the Intent
String data = intent.getStringExtra("message");
if (!data.equals("0")) {
//Do something
} else {
//Do something else
}
}
}
};
now i have a server class that i run on a thread from an activity(i.e servActivity).now when i am not interacting with my app in anyway possible (like i have removed it from recent apps etc) the thread should stop which currently is not stopping. So i researched and i found that i should use a bound service. now a bound service i will have to bind it to servActivity and when servActivity is destroyed i have to unbind and stop service but i dont want to do that. i want to stop service when i am not interacting with the app. i also found that maybe i have to extend application class but cannot find the solution to achieve this?Is it advisable to extend the application class?
i want to be able to create a service running on independent thread from a particular activity(ie servActivity) and then be able to interact with the service from any activity and service should be active (even if the activity in which i started the service i.e-servActivity is destroyed by going to previous activity etc) through button or whatever until i am not interacting with the app(i have a notification controller which also needs to be closed to stop the interaction)
i have a client class on one device whose object i create again and again if i have to make request but i want to make only one object for server class because it has a while(true) loop so it keeps running so i want to be able to interact with the server from all activities and stop it when i am not interacting with the application
i also found a way in which i can make an abstract class which extends activity and extend that derived class to all the other activities in my app.But how to i bind the service to all the other activities in the class so that i can interact with the service from all the other activities?And how would i know that if all activities and notification controller have been stopped and there is no interaction with user?something like this how to know our app has gone to background in android
If there is there any other method please suggest
Please help
thanks in advance
You can create a BroadcastReceiver in your Service Class to interact/start/close your Service from any Activity or even from any App.
Your Activities can broadcast custom Action Strings which can be picked up by any BroadcastReceivers (even ones set up in Services) and thereby invoking their onReceive() methods allow communication.
1) I suggest you don't bind your Service to any Activity and instead use Intent to initiate it in your Activity like this....
//In your Activity
Intent i = new Intent(this, /*MyServiceClassName.class*/);
startService(i);
Or else your Service may still be active until you unbind it.
2) Create a BroadcastReceiver in your Service Class to listen for certain Action Strings broadcasted by your Activities....
//In your Service
private final BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if(action.equals(/*"Action String to stop Service"*/)){
stopSelf();
}else if(action.equals(/*"Action string to interact with Service"*/)){
//Do what you want
};
3) Now set what Action Strings the Broadcast Receiver will listen for and also register it in your Service onCreate() method....
//In your Service onCreate() method
IntentFilter filter = new IntentFilter();
filter.addAction(/*"Action String to stop Service"*/);
filter.addAction(/*"Action String to do something"*/);
registerReceiver(receiver, filter);
4) And also unregister your receiver when Service onDestroy() is invoked as housekeeping....
//Service onDestroy()
#Override
public void onDestroy(){
super.onDestroy();
unregisterReceiver(receiver);
}
5) Finally broadcasting Action Strings from your Activities through Intent....
//From any Activity
Intent intent = new Intent(/*"your custom Action String that should match
up with whats set up with the BroadcastReceiver in Service"*/);
sendBroadcast(intent);
6) So once the broadcast is sent your receiver should pick it up then its onReceive() method will be invoked. Therefore you now have a medium for your Activities and Service to communicate through and also the Service will persist even after you close your app until you stop it explicitly with....
//From any Activity
Intent i = new Intent(this, /*MyServiceClassName.class*/);
stopService(i);
7) Stop service when app is stopped....
//In all your activities
#Override
protected void onDestroy() {
Intent i = new Intent(this, /*MyServiceClassName.class*/);
stopService(i);
super.onDestroy();
}
8) First you'd need to put a killcode intent action String in your Service as demonstrated in points 2 and 3 then put this code in your app's Activity onPause() methods....
#Override
protected void onPause() {
PendingIntent pintent = PendingIntent.getBroadcast( this, 0, new Intent(/*"Action String to stop Service"*/), 0 );
AlarmManager manager = (AlarmManager)(this.getSystemService( Context.ALARM_SERVICE ));
// set alarm to fire 10mins (1000*60*10) from now (SystemClock.elapsedRealtime())
manager.set( AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 1000*60*10, pintent );
super.onPause();
}
And this in your app's Activity onResume() methods....
#Override
protected void onResume() {
PendingIntent pintent = PendingIntent.getBroadcast( this, 0, new Intent(/*"Action String to stop Service"*/), 0 );
AlarmManager manager = (AlarmManager)(this.getSystemService( Context.ALARM_SERVICE ));
manager.cancel(pintent);
super.onResume();
}
I am making an app where I receive XMPP packets. My app starts in foreground and starts a Sticky Service if not started and start receive messages in backgrounds and make notifications of them. The notifications works well and when clicked they show the data. Issue comes (that too sometimes in some mobile phones) when I make a sendBroadcast call from service so that I can asynchronously update the text of message in Activity when it is opened.
My app is made with a Activity and within that there are two Fragments(SherlockFragment)
So I made a private broadcastreceiver in one of fragment where I want to show the text (updated text).
Code is written below
public class newMessage extends BroadcastReceiver
{
#Override
public void onReceive(Context context, Intent intent)
{
Log.v("ONMESSAGE", "broadcast");
String action = intent.getAction();
if(action.equalsIgnoreCase("NewMessage")){
Bundle extra = intent.getExtras();
String username = extra.getString("from");
String message = extra.getString("message");
showMessage(username, message);
Log.v("ONMESSAGE", "in broadcast is " + username);
}
}
}
I then make a statement of below in Fragment class
private newMessage messageReceiver = new newMessage();
in onCreateView I wrote the below line
getActivity().registerReceiver(messageReceiver, new IntentFilter("NewMessage"));
I did not unregister the broadcast receiver now and I tried doing that too.
When I receive a message in my service, I made call to below code.
Intent i = new Intent("NewMessage");
i.putExtra("message", message);
i.putExtra("from", from);
context.sendBroadcast(i);
I did not add the broadcats to to manifest cause I dont know how to do it when written inside a class.
Sometimes, it calls the sendbroadcase and everything works well however sometimes it does not call and just generate the notification.
I have a running Service and I have a BroadcastReceiver and an Activity that interacts with said Service.
Basically, when the BroadcastReceiver#onReceive() activates, it calls the service so onStartCommand() will trigger. When called by this component, the service should just change a boolean value form false to true
When the Activity calls the Service, it also should change another boolean value from false to true.
In order to identify where is the Service being called from, I pass a custom action via the Intent like this:
Intent intent = new Intent(this, MyService.class);
intent.setAction("change_boolean_1_to_true");
startService(intent);
And then, in the Service I do:
String action = intent.getAction();
if(action != null) {
Log.d(TAG,"Action found"); .......
But the Log doesn't print anything, which means the action is comming null.
My question would be:
Is it appropriate to pass an Intent Action to do this?
Why is it not working?
I'm wanting to implement what CommonsWare describes on this blog post: http://commonsware.com/blog/2010/08/11/activity-notification-ordered-broadcast.html. The post makes sense, and I was able to browse the example source here: https://github.com/commonsguy/cw-advandroid/tree/master/Broadcast.
What I'm curious about is if calling LocalBroadcastManager.getInstance(UnzipService.this).sendBroadcast(broadcast); inside of a service will still be picked up by a broadcast receiver of the type you define in your manifest.
In case what I'm asking isn't clear, what I'm trying to do is use the LocalBroadcastManager because the broadcasts from my service don't necessarily need to be seen system wide and I'd rather keep them private if possible, but I also want to display notifications if the user closes my app and the service is still running. Is there a way to combine both of those capabilities without sending a broadcast twice inside of the service?
(What I don't want to have to do) like:
LocalBroadcastManager.getInstance(UnzipService.this).sendBroadcast(broadcast);
sendOrderedBroadcast(broadcast);
What I'm curious about is if calling LocalBroadcastManager.getInstance(UnzipService.this).sendBroadcast(broadcast); inside of a service will still be picked up by a broadcast receiver of the type you define in your manifest.
No. LocalBroadcastManager only works with receivers registered with the LocalBroadcastManager singleton itself. Moreover, LocalBroadcastManager does not support ordered broadcasts, last I checked.
what I'm trying to do is use the LocalBroadcastManager because the broadcasts from my service don't necessarily need to be seen system wide and I'd rather keep them private if possible
So long as you are not using an <intent-filter> on your BroadcastReceiver in the manifest, and therefore are using an explicit Intent as the broadcast itself, your broadcast will only be seen by yourself and the bit of the OS that manages broadcasts. Other apps will not be able to spy upon it.
If you only have 2 objects that might handle your broadcast (in your case an Activity and a notifications controller), you can achieve the behavior of a ordered broadcast using only the LocalBroadcastManager.
The general idea is:
Set up your Service so that it broadcasts an Intent to your Activity with a particular action when you want to display your result
In your Activity create a BroadcastReceiver that handles your Service result Intent, and register it on the LocalBroadcastManager with an IntentFilter using the action from step 1
In your Service, when the results are available, try to send the result Intent using LocalBroadcastManager.getInstance(Context).sendBroadcast(Intent) this method returns a boolean that indicates if the broadcast has been sent to at least one receiver. If this boolean is false, it means that your Activity didn't handle your broadcast and you should show a notification instead.
In your service:
public UnzipService extends IntentService {
public static final String ACTION_SHOWRESULT = UnzipService.class.getCanonicalName() + ".ACTION_SHOWRESULT";
#Override
protected void onHandleIntent(Intent intent) {
Thread.sleep(500); // Do the hard work
// Then try to notify the Activity about the results
Intent activityIntent = new Intent(this, YourActivity.class);
activityIntent.setAction(ACTION_SHOWRESULT);
activityIntent.putExtra(SOME_KEY, SOME_RESULTVALUE); // Put the result into extras
boolean broadcastEnqueued = LocalBroadcastManager.getInstance(this).sendBroadcast(activityIntent);
if (!broadcastEnqueued) { // Fallback to notification!
PendingIntent pendingIntent = PendingIntent.getActivity(this, (int) System.currentTimeMillis(), activityIntent, PendingIntent.FLAG_UPDATE_CURRENT);
((NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE))
.notify(SOME_ID, new NotificationCompat.Builder(this)
.setContentIntent(pendingIntent)
.setTicker("results available")
.setContentText("results")
.build());
}
}
}
In your Activity:
public YourActivity extends Activity {
private BroadcastReceiver resultReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
processResult(intent); // Results Intent received through local broadcast
}
}
private IntentFilter resultFilter = new IntentFilter(UnzipService.ACTION_SHOWRESULT);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate();
Intent intent = getIntent();
if (UnzipService.ACTION_SHOWRESULT.equals(intent.getAction())) {
// The Activity has been launched with a tap on the notification
processResult(intent); // Results Intent contained in the notification PendingIntent
}
}
#Override
protected void onResume() {
super.onResume();
LocalBroadcastManager.getInstance(this)
.registerReceiver(resultReceiver, resultFilter);
}
#Override
protected void onPause() {
LocalBroadcastManager.getInstance(this)
.unregisterReceiver(resultReceiver);
super.onPause();
}
private void processResult(Intent intent) {
// Show the results from Intent extras
}
}
This should be a complete working example.
I hope this helps who is trying to implement ordered broadcasts with LocalBroadcastManager from support library!
I understand you want to achieve the following:
"I have an event that occurs in the background. I want to update my activity, if the activity is on the screen. Otherwise, I want to raise a Notification." (#TheCommonsBlog)
You can achieve this behaviour by implementing a ResultReceiver.
Examples Restful API service and
http://itekblog.com/background-processing-with-intentservice-class/
What you basically do is instance a ResultReceiver in your Activity and pass it to the Service like a Parcelable parameter through an intent. Then, each time your service whats to update the UI, the service verifies the ResultReceiver object for NULL. If not NULL, you update the Ui via the onReceiveResult interface. Else, you raise a notification. When your activity dismisses, make sure you set the ResultReceiver on the Service to NULL.
Hope it helps.
PS: IMO, broadcasts are too much work and hard to control.
Use LocalBroadcastManager and broadcasts become easy to use.
I am not in favor of updating an Activity if an event occurs in the background. The user might already be doing something else in the Activity. Seems to me that a Notification is sufficient; it's always visible and remains until the user dismisses it. Gmail and Gcal work like this; Gmail doesn't update the current screen if a new mail comes in. If you want to know how to handle the task flow for handling a notification when the user is already in the app, see the Notifications API guide and also the [Notifying The User2 training class.