Background activity blocked while using AlarmManager. (Android Q privacy change) - android

In my project I am using AlarmManager in order to trigger daily AlarmClock but when the time comes to start an alarm following toast message occurs:
Background activity start from com.example.nameOfApp blocked. See g.co/dev/bgblock
Updated code:
-------setAlarmClock method-------
private void setAlarmClock(Calendar calendar, int alarmId, String time, String timeOfTheDay, boolean action) {
AlarmManager manager = (AlarmManager) getActivity().getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(getActivity(), AlarmClockReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getActivity(), alarmId, intent, 0);
if (action) {
manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
AlarmManager.INTERVAL_DAY, pendingIntent);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
manager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
}
} else {
manager.cancel(pendingIntent);
}
}
-------AlarmClockReceiver class-------
public class AlarmClockReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
String alarmAction = AlarmClock.ACTION_SET_ALARM;
Intent i = new Intent(alarmAction);
i.putExtra(AlarmClock.EXTRA_SKIP_UI, true);
i.putExtra(AlarmClock.EXTRA_MESSAGE, "Time for taking medicine!");
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
}
Moreover in AndroidManifest I included following line:
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
I am aware that it's connected with new Android Q privacy change. From the aforementioned link it's said:
Apps running on Android Q can start activities only when one or more of the following conditions are met:
...
The app receives a notification PendingIntent from the system. In the case of pending intents for services and broadcast receivers, the app can start activities for a few seconds after the pending intent is sent.
If I understood it correctly this is exactly my case. Nevertheless aforementioned toast message occurs.

The PendingIntent is valid (in order to start an activity) only if you set the intent in a notification using the method setContentIntent. So what you can do is to post a notification instead of starting directly an activity. When the user tap on the notification the pending intent will be used to start the activity.
Edit: as alternative you need to ask the SYSTEM_ALERT_WINDOW permission but you won't be able to execute the app on Android Go because it's not possible to use this permission on that version.

Related

dynamic alarm manager at midnight

my mean goal is to run a task periodically at midnight (00:00:00)
but the user can set the period based on the interval (daily, weekly , monthly)
let's assume that this job is a backup Scheduling.
this task will triggred at midnight but based on the user preference (midnight everyday, every week , or monthly ), and if the phone was in the doze mode or even off , wait untill the next start and start backup.
when i start implementing the code , i started with JobService and JobScheduler , but unfortunately i learned that i can set the repetitive but i can't set the exact time, so the last solution was to work with alarmmanager.
i use this code for triggering the alarm :
public static void setTheTimeToStartBackup(Context context,String periode) {
int DATA_FETCHER_RC = 123;
AlarmManager mAlarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
Intent intent = new Intent(context, BackUpAlarmRecevier.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, DATA_FETCHER_RC,intent, PendingIntent.FLAG_UPDATE_CURRENT);
long interval = 0;
switch (periode){
case "never":
return;
case "daily":
alarmStartTime.set(Calendar.HOUR_OF_DAY, 0);
interval = AlarmManager.INTERVAL_DAY;
break;
case "weekly":
alarmStartTime.set(Calendar.DAY_OF_WEEK, 1);
interval = AlarmManager.INTERVAL_DAY*7;
break;
case "monthly":
alarmStartTime.set(Calendar.WEEK_OF_MONTH, 1);
interval = AlarmManager.INTERVAL_DAY*30;
break;
}
alarmStartTime.set(Calendar.HOUR_OF_DAY, 0);
alarmStartTime.set(Calendar.MINUTE, 0);
alarmStartTime.set(Calendar.SECOND, 0);
mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),interval, pendingIntent);
Log.e("Alarm","Set for midnight");
}
this is my receiver :
public class BackUpAlarmRecevier extends BroadcastReceiver {
SharedPreferences preferences;
#Override
public void onReceive(Context context, Intent intent) {
Log.e("BackUpAlarmReciver","Triggred");
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "TAG:APP");
wl.acquire();
sendNotification(context);// simple notification...
Toast.makeText(context, "Alarm !!", Toast.LENGTH_LONG).show();
startBackupProcess();
wl.release();
}}
the problem is task never start.
so i went to test it with less time interval (15min as the minimum possible as i read ), so i change my first function setTheTimeToStartBackup to this :
public static void setTheTimeToStartBackup(Context context,String periode) {
int DATA_FETCHER_RC = 123;
AlarmManager mAlarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.SECOND, 55);
Intent intent = new Intent(context, BackUpAlarmRecevier.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, DATA_FETCHER_RC,intent, PendingIntent.FLAG_UPDATE_CURRENT);
mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP,calendar.getTimeInMillis(),AlarmManager.INTERVAL_FIFTEEN_MINUTES, pendingIntent);
Log.e("Alarm","Set for midnight");
}
and exactly the same problem , nothing started, no log , no notification , nothing.
and i already set the Receiver in my manifest with all permission like that :
<receiver android:name=".job.BackUpAlarmRecevier"
android:enabled="true"
android:process=":remote"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
what im doing wrong in both cases ? and if it work , this code will persist for ever or i need to set it again each time ?
thanks :)
EDIT:
i call my function setTheTimeToStartBackup in the MainActivity.
You could set it to occur at midnight if you did the appropriate time calculations. Dynamically get the current time and date, calculate when to register the broadcast for the alarm manager. Customize the onReceive method to set another alarm at 12pm again.
Either way you can trigger a broadcast receiver by registering your receiver manually.
Broadcast receiver class:
public class AlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
System.out.println("Alarm received!! ");
// Register alarm again here.
}
}
Code to register a receiver with a custom intent filter.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AlarmManager mAlarmManager = (AlarmManager)getApplicationContext().getSystemService(Context.ALARM_SERVICE);
getApplicationContext().registerReceiver(new AlarmReceiver(), new IntentFilter("AlarmAction"));
PendingIntent broadcast = PendingIntent.getBroadcast(this, 0, new Intent("AlarmAction"), 0);
// Add dynamic time calculations. For testing just +100 milli.
mAlarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 100, broadcast);
;
}
You could achieve what you wanted through a background service.
My suggestion would be to turn the problem around a bit.
Create three topics on Firebase (daily, weekly, monthly). Subscribe users to appropriate topics. Have a Firebase function that is triggered by CRON job which sends the data notification down to the device, this data notification should schedule one-time WorkManager job for the update. This way you can control everything from server-side, if the phone is off, it will still execute as soon as it turns on and you don't need to manually take care of catching the Boot completed with alarm manager etc.

AlarmReceiver not waking up app

With the following code, the AlarmReceiver.onReceive() is not called when it should be after the app is killed manually (to simulate the OS killing the app on a whim).
What must I do so that the AlarmReceiver still works after the OS kills it?
Manifest:
<receiver
android:name="abc.def.AlarmReceiver"
android:enabled="true"
android:exported="false"
/>
AlarmReceiver:
public class AlarmReceiver extends BroadcastReceiver {
public void setupAlarm(Context context, int intervalMS) {
this.interval = interval;
Calendar updateTime = Calendar.getInstance();
updateTime.add(Calendar.SECOND, 5);
Intent alarmIntent = new Intent(context, AlarmReceiver.class);
PendingIntent recurringDownload = PendingIntent.getBroadcast(context, 123, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarms.setRepeating(AlarmManager.RTC_WAKEUP, updateTime.getTimeInMillis(), intervalMS, recurringDownload);
}
#Override
public void onReceive(Context context, Intent intent) {
Log.d("Alarm", "hello world!");
}
}
When you kill it manually, you're putting the app into the forced stop state. That stops all Receivers and Services until you start it by hand again. That's not the same as being killed by the OS.
Normal process termination(by OS) does not cancel scheduled AlarmManager events. So, the alarms would still work after OS kills the process.
If you are manually force-closing the app, your alarms are unregistered. And, on Android 3.1+, you have to manually launch one of the activities to register them again.
So by killing the app manually you are not exactly simulating the OS killing the app
android:exported="false" means you don't allow your app to receive any events from system. Change it to true
One more thing, make sure you call setupAlarm in Context
From the documentation of google
Whether or not the broadcast receiver can receive messages from sources outside its application — "true" if it can, and "false" if not. If "false", the only messages the broadcast receiver can receive are those sent by components of the same application or applications with the same user ID.
The default value depends on whether the broadcast receiver contains intent filters. The absence of any filters means that it can be invoked only by Intent objects that specify its exact class name. This implies that the receiver is intended only for application-internal use (since others would not normally know the class name). So in this case, the default value is "false". On the other hand, the presence of at least one filter implies that the broadcast receiver is intended to receive intents broadcast by the system or other applications, so the default value is "true".
This attribute is not the only way to limit a broadcast receiver's external exposure. You can also use a permission to limit the external entities that can send it messages (see the permission attribute).
All is accordingly but in the code may be you have not called your setupAlarm() method in onRecieve().
public class AlarmReceiver extends BroadcastReceiver {
public void setupAlarm(Context context, int intervalMS) {
this.interval = interval;
Calendar updateTime = Calendar.getInstance();
updateTime.add(Calendar.SECOND, 5);
Intent alarmIntent = new Intent(context, AlarmReceiver.class);
PendingIntent recurringDownload = PendingIntent.getBroadcast(context, 123, alarmIntent, PendingIntent.FLAG_CANCEL_CURRENT);
AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarms.setRepeating(AlarmManager.RTC_WAKEUP, updateTime.getTimeInMillis(), intervalMS, recurringDownload);
}
#Override
public void onReceive(Context context, Intent intent) {
Log.d("Alarm", "hello world!");
setupAlarm(context,2000);//May be this line is missing.
}
}

How to keep a service alive using AlarmManager.setInexactRepeating()?

I have some existing code that spawns a service intent which does a bunch of stuff in the background. This code does work...
Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startService(serviceIntent);
My question is: how to change this to use the AlarmManager.setInexactRepeating(...) methods?
I have changed the above code to this:
Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.putExtra("STARTED_BY", starter);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
//Set up recurring alarm that restarts our service if
// it crashes or if it gets killed by the Android OS
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(context, 0, serviceIntent, 0);
//am.cancel(pi);
am.setInexactRepeating(
AlarmManager.ELAPSED_REALTIME_WAKEUP //wake up the phone if it's asleep
, cal.getTimeInMillis()
, 10000
, pi);
And I have added these permissions to AndroidManifest.xml...
<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<uses-permission android:name="com.android.alarm.permission.WAKE_LOCK"/>
My understanding is that this is supposed to start the service immediately and then try to restart it again every 10 seconds. But this code isn't working properly.
Using this new code, the service never starts at all and I cannot see why not. To complicate matters the debugger never seems to attach to the app in time to see what's going on.
Can anyone see what I'm doing wrong?
Put AlarmManager code under onDestroy() function of service to schedule start of service as below:
#Override
public void onDestroy() {
/**
* Flag to restart service if killed.
* This flag specify the time which is ued by
* alarm manager to fire action.
*/
final int TIME_TO_INVOKE = 5 * 1000; // try to re-start service in 5 seconds.
// get alarm manager
AlarmManager alarms = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(context, AutoStartServiceReceiver.class);
PendingIntent pendingIntent = PendingIntent
.getBroadcast(context, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
// set repeating alarm.
alarms.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() +
TIME_TO_INVOKE, TIME_TO_INVOKE, pendingIntent);
}
And handle starting of your service in AutoStartServiceReceiver as below:
public class AutoStartServiceReceiver extends BroadcastReceiver {
private static final String TAG = AutoStartServiceReceiver.class.getSimpleName();
#Override
public void onReceive(Context context, Intent intent) {
// check broadcast action whether action was
// boot completed or it was alarm action.
if (intent.getAction().equals(AppConstants.ACTION_ALARM_INTENT)) {
context.startActivity(new Intent(context, YourActivity.class));
// handle service restart event
LockerServiceHelper.handleServiceRestart(context);
}
}
}
Kindly note that, your service will not restart if you stop it manually from settings-apps-running apps-your app.
Your service is not starting because of AlarmManager.ELAPSED_REALTIME_WAKEUP, while it should be using AlarmManager.RTC_WAKEUP
If you want to run every 10s keep in mind that above API 21 alarm intervals below 60s are rounded up to 60s.
Also, consider using WakefulIntentService
https://github.com/commonsguy/cwac-wakeful

Schedule a GPS location check daily at a predefined time in Android

I'm from an iOS background with intermediate Android knowledge. Anyways for this task, I need to know what exactly I need to work with. My app needs to check if the user is at or close to the predefined location at a predefined time. Getting user location is not an issue.
My guess is working with a combination of AlarmManager, BroadcastReceiver and Service ? I haven't worked with either of these three.
Any help is appreciated. :)
These are the ingredients you need for you recipe:
An Intent that targets your BroadcastReceiver:
Intent intent = new Intent(context, YourBroadCastReceiver.class);
A PendingIntent that gets triggered by the AlarmManager and fires your already defined Intent:
PendingIntent pIntent = PendingIntent.getBroadcast(context, requestCode, intent, flags);
The AlarmManager that periodically activates your PendingIntent:
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
am.setRepeating(AlarmManager.RTC_WAKEUP, triggerAtMillis, intervalMillis, pIntent);
The BroadCastReceiver that handles the event:
#Override
protected void handleReceive(Context context, Intent intent) {
// handle GPS
}

AlarmManager Not called next day if the app sleeps for abt 1 day

I am developing an android app which shows a notification every 12 hour if the time is saved in the database. So everytime a data is entered or edited in the database ,I cancel the current alarmmanager and start a fresh new one so that I dont miss one. Also on reboot I have called the alarmmanager. On the broadcast receiver, the database is checked for entry and if found a notification is set and the app is opened automatically.
So when I test the app by changing the date manually,the app works as expected.Also on reboot the app works.But if I keep the app idle for nearly 14 hours,the notification is not set ,but if I open the app and suspend it the notification is set after that.
This is how I call the alarmmanager.
Intent alarmintent = new Intent(context, package.Alarm_Manager.class);
alarmintent.putExtra("note","Notify");
sender = PendingIntent.getBroadcast(context , 0 , alarmintent , PendingIntent.FLAG_CANCEL_CURRENT | Intent.FILL_IN_DATA);
alarm_manger = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
alarm_manger.cancel(sender);
Calendar cal = Calendar.getInstance();
long now = cal.getTimeInMillis();
alarmintent = new Intent(context, package.Alarm_Manager.class);
alarmintent.putExtra("note","Notification");
sender = PendingIntent.getBroadcast(context , 0 , alarmintent , PendingIntent.FLAG_CANCEL_CURRENT | Intent.FILL_IN_DATA);
alarm_manger = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarm_manger.setRepeating(AlarmManager.RTC_WAKEUP, now, AlarmManager.INTERVAL_HALF_DAY, sender);
This is the broadcast receiver
#Override
public void onReceive(Context context, Intent intent)
{
NotificationManager manger = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
Calendar cal = Calendar.getInstance();
date = (int)(cal.getTimeInMillis()/1000);
Notification notification = new Notification(R.drawable.vlcsnap_396460 , "Notify" , System.currentTimeMillis());
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, intent, 0);
notification.setLatestEventInfo(context, "App", "Notify" , contentIntent);
notification.flags = Notification.FLAG_INSISTENT;
manger.notify( 0 , notification);
}
You don't need to call alarm_manager.cancel(sender); if you set the PendingIntent.FLAG_CANCEL_CURRENT.
Your call to
alarm_manger.setRepeating(AlarmManager.RTC_WAKEUP, now, AlarmManager.INTERVAL_HALF_DAY, sender);
will trigger the alarm right away, since the now is already passed when you set the alarm.
I suggest you use
now + DateUtils.HOUR_IN_MILLIS / 2
for the triggerAtMillis parameter
Did you tried to schedule it for smaller interval? Does it get triggered ?
After having seen your Alarm_Manager code, I think it is illegal to do this in your BroadcastReceiver object directly. Quote:
If this BroadcastReceiver was launched through a tag, then the object is no longer alive after returning from this function.
I believe there is no other way than to create a Service which is informed by your BroadcastReceiver, and make sure that the Service calls setLatestEventInfo() with itself (this) as the Context.
The reason why your asynchronous Broadcast fails while it works when your app is running is probably that the Context provided to the BroadcastReceiver lives only for the duration of the call to the BroadcastReceiver when your app does not run. So the Notification service, which only runs after your BroadcastReceiver has died along with the temporary context, is missing a valid context.
When your app runs, the Broadcast probably comes with your Activity or Application object as Context, and this is still vaild when the Notification manager runs.
Hope this helps.
Update: An `IntentService`` will do. You don't want a full time Service for that.
Update 2: Some snippets.
<service android:name=".MyIntentService" android:label="#string/my_intent_service_name" />
public final class MyIntentService extends IntentService {
public MyIntentService() {
super("service name");
// set any properties you need
}
#Override
public void onCreate() {
super.onCreate();
// do init, e.g. get reference to notification service
}
#Override
protected void onHandleIntent(Intent intent) {
// handle the intent
// ...especially:
notification.setLatestEventInfo(this, "App", "Notify" , contentIntent);
// ...
}
}
public final class MyAlarmReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
context.startService(new Intent(context, MyIntentService.class));
}
}

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