I dont now if question already exists but i really need help. I need to upload data in intervals (hour, daily etc.). Interval information comes from the spinner (put to SharedPreferences) and when the interval is picked, timer(Handler) needs to start count. The main problem is how to make broadcast receiver to sart on spinner itemchecked, from main activity? Maybe its better way to start it with service, but how to start broadcast on spinner item selected in service. I hope someone understands the problem.
You could write the code that handles the uploads as a service and then start that service via the AlarmManager
http://developer.android.com/reference/android/app/AlarmManager.html
Intent intent = new Intent(this, myUploadService.class);
PendingIntent pintent = PendingIntent.getService(this, 0, intent, 0);
AlarmManager alarm = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarm.setRepeating(AlarmManager.RTC_WAKEUP, yourWakeUpTime, interval, pintent);
so the intent will be your service.
yourWakeUpTime is the time when the service should start first.
interval will be the time selected from your spinner.
Related
I'm building a reminders application where one time, weekly, monthly reminders and we notify the user of the reminder on due date and time. Reminders can be updated any time by the user to update the reminding time or delete the reminder altogether. I have thought of two ways I can solve the particular problem.
Whenever user sets a reminder, schedule an alarm accordingly with an unique Id and update or delete it in case user updates or deletes the alarm.
Since I store the reminding time in DB, better approach would be to schedule an alarm for the nearest reminder. And have the Service which is triggered by the alarm schedule a new alarm for the next nearest reminder.
2nd approach seems clean approach but how do we tackle the case where the Service triggered by alarm gets killed by the system before it schedules a new alarm for the next reminder?
Edit
Looks like if the system kills a Service for memory, it will re-create the Service. Does it mean it is safe to rely on the Service to schedule alarm every time it is run?
Edit 2
I've realized that Android kills any alarms whenever the device is restarted. This makes approach 2 a better solution. I've implemented it for now.
The pending intent needs to be created exactly in the same way for canceling the already set alarm. You can cancel previous alarm when you set a new alarm, if you want to have a single alarm activated at some time.
For setting alarm use:
Intent myIntent = new Intent(getApplicationContext(), SessionReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManager.set(AlarmManager.RTC, now.getTimeInMillis(), pendingIntent);
For canceling the alarm use:
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent myIntent = new Intent(getApplicationContext(), SessionReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1, myIntent, PendingIntent.FLAG_UPDATE_CURRENT);
alarmManager.cancel(pendingIntent);
I'm usign an Alarm Manager to update a widget with a Service. I've two different questions.
First question: I'm calling the service with Alarm Manager's intent. Like this:
alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, MyService.class);
pi = PendingIntent.getService(context, 0, i, PendingIntent.FLAG_UPDATE_CURRENT);
context.startService(new Intent(context, MyService.class));
Long repeat = Long.parseLong(prefs.getString("update_preference", "600"));
alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, Calendar.getInstance().getTimeInMillis(), 1000*repeat, pi);
Is it wrong?
It looks and works right. But when I have looked at working services, I can't see my service name in the list. Perhaps it's not running as a single/seperate service. Just saw application name (not as a service). I'm not sure how to seperate or does it matter?
Another question: Over long time, running application, which controls widgets update, is closed somehow (manually or by a task killer). Of course Alarm Manager gonna stop and widget's functions gonna stop too. For example button clicking.
But, Twitter solved this problem. While the widget is active, if I close the main application (Twitter) -which controls widget- than click the widget, somehow widget triggering application and it starts again well. So buttons work properly. How is that possible?
Any help would be appreciated.
You dont need to do context.startservice that what the pending intent is for, if you want the service to run right away the first time just set it to run at the current time then set the interval from the current time.
You are also setting 2 different types of repeating when you don't need to setRepeating is strict where setInexact is not and can be adjusted by the OS when it gets fired hence the inexact in it. You want one or the other not both.
Also those intervals are very small and its going to kill the battery significantly.
It should just be this
alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, MyService.class);
pi = PendingIntent.getService(context, 0, i, PendingIntent.FLAG_UPDATE_CURRENT);
Long repeat = Long.parseLong(prefs.getString("update_preference", "600"));
alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP,
Calendar.getInstance().getTimeInMillis(), 1000*repeat, pi);
It's good that your application/service isn't running all the time.
In fact it doesn't need/has to run all the time for updating a widget. If you schedule an Intent with AlarmManager the application will be started when the intent is fired if it has been closed.
Im creating a news-like app and I want to know is is possible to start app (ex : 1 time per 1h) to check if new data is available. You know what im talking about, I think. App should start from nowhere, check and finish().
Is this possible? I know that widgets can do it but normal activity or something like this?
Please, help.
Damian.
Yes, It is possible to use an "Alarm Service" in android, and use it to perform some work, at specific intervals.
Here is the link to Alarm Service documentation:
http://developer.android.com/reference/android/app/AlarmManager.html
Here is a sample code which uses Alarm Service
/**
* Method to start background service for server refresh and other tasks.
*/
public void startMyService()
{
//Start Service service to handle data refresh
Intent serviceIntent = new Intent(this, MyCommunicationService.class);
//Schedule additional service calls using alarm manager.
AlarmManager alarmManager = (AlarmManager) this.getSystemService(ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(this, 0, serviceIntent, 0);
//Retrieve time interval from settings (a good practice to let users set the interval).
MyPreferenceManager prefManager = new MyPreferenceManager(this);
alarmManager.cancel(pi);
alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), prefManager.getDataRefreshTime()*1000 , pi);
}
Note that we are multiplying with 1000, because the parameter for setRepeating() method is in milliseconds.
I have an application that does some data processing, then notifies the user in the status bar if any new items are found. The process runs as an AlarmManager at a set amount of time. Everything works fine, but I'd ideally not like the user to be notified while they are actively using the application, which means the AlarmManager should basically be suspended. The only solution I could think of is constantly start/stop the alarm in the main Activity's onResume method similar to this:
#Override
public void onResume()
{
AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
Intent myIntent = new Intent(this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, myIntent, 0);
alarmManager.cancel(pendingIntent);
alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + 600000, 600000, pendingIntent);
}
This isn't foolproof, but the best solution I could think of. Just wondering if that is bad practice or if there is a better solution? Thanks.
Just have your AlarmReceiver (or the Service it invokes) check to see if the app is visible or not. You need to share some state between your app and the AlarmReceiver/Service. You could have a base Activity that tells your AlarmReceiver/Service that is in the foreground during onResume and that it is in the background during onPause. Then the AlarmReceiver/Service can simply check this state when the alarm goes off and use that to decide if a notification should be shown or not.
When setting a service to go off at particular time, I use the AlarmManager system service.
Everything goes off without a problem, service is called and actions take place.
When the alarm time is reached, the service starts, and at this point I get the system time (System.currentTimeMillis()). I'm guessing this wont be the actual time the service start. Is there a way to get the time that was set for this PendingIntent?
ie
Set alarm for 9am.
DoStuffService starts at 9am.
DoStuffService knows it was supposed to start at 9am, and uses this value for future functions.
When you create an intent for your alarm, you could put extra data, including time of the alarm, into it like this:
Intent intent = new Intent("action name");
//put extra data into the intent:
intent.putExtra("alarm_time_hours", hours);
intent.putExtra("alarm_time_minutes", minutes);
PendingIntent sender = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), sender);
Then in your receiver or service you need to get this extra data from received intent. Use something like this:
Bundle bundle = intent.getExtras();
if(bundle.containsKey("alarm_time_hours")) {
int hours = bundle.getInt("alarm_time_hours");
}
if(bundle.containsKey("alarm_time_minutes")) {
int minutes = bundle.getInt("alarm_time_minutes");
}
Is there a way to get the time that was set for this PendingIntent?
No, sorry.
However, it should not be terribly difficult for you to determine it yourself. Following your example, if your service reports that it is now 09:00:02.36, you should be able to round down to determine that this is the 9am alarm.