I have created a configure activity for my widget, where the user can choose from various update frequencies.. Until now I started the alarm in the OnEnabled() method, like this:
Intent intent = new Intent(CLOCK_WIDGET_UPDATE);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC, System.currentTimeMillis(), 1000 * 60,
pendingIntent);
The settings are saved in shared preferences with a unique name (widgetId) and in this OnEnabled() method I can't retrieve the settings here because I can't get the widgetId yet.
There's an another problem, the user can change the frequency anytime, but this method is called just once, at the beginning. So I think I need to start the alarm in OnUpdate(), but I don't know how to do it, I don't want to make multiple instances of an alarm accidentally so I would like to ask for some advice.
To answer your second problem, calling setRepeating multiple times will not create multiple alarm as far as you provide same PendingIntent and same request code along with PendingIntent.FLAG_UPDATE_CURRENT flag. I would also suggest to use setInexactRepeating instead of setRepeating. So you can use the same code in OnUpdate() too with new frequency. Go through docs of FLAG_UPDATE_CURRENT and setInexactRepeating for more detials.
Related
I set up an alarm for my PendingIntent. Now I want to show in my activity, if this alarm is set or not.
Intent service = new Intent(context, MyService.class);
PendingIntent pendingIntent = PendingIntent.getService(context, 0, service, 0);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, firstStart, interval, pendingIntent);
Is there any way to check is this alarm is set?
You can't query the AlarmManager to find out if the alarm is set. You pretty much need to remember yourself. You can store something in shared preferences to indicate that you set the alarm. However, once the phone is restarted your alarms are gone, so you also need to either reschedule the alarms on a reboot OR clear your preferences to indicate the alarm is no longer set.
Unfortunately, this is one of those things that Android really lacks (a way to query the alarmManager).
My app will have several alarms set simultaneously. Unfortunately, each alarm is being set with the same PendingIntent object. Here's the code I'm using to set the alarm:
//Use AlarmManager to trigger the notification/alarm.
AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
//PendingIntent to launch activity when the alarm triggers.
Intent i = new Intent("com.testapp.DisplayNotification");
//Assign the reminder's primary key as the notification ID.
i.putExtra("Reminder_Name", editRemindMeTo.getText().toString());
i.putExtra("Reminder_Primary_Key", reminderPrimaryKey);
PendingIntent displayIntent = PendingIntent.getActivity(
getBaseContext(), 0, i, 0);
//Set the alarm to trigger.
alarmManager.set(AlarmManager.RTC_WAKEUP,
c.getTimeInMillis(), displayIntent);
I know that I can delete an alarm by using the following code:
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, MyPendingIntentService.class);
PendingIntent displayIntent = PendingIntent.getService(context, 0, i, 0);
alarmManager.cancel(displyIntent);
However, using this code will delete ALL my alarms (correct me if I'm wrong here). Is there a way to delete just the alarm that a user has deleted from the database? The alarm should be deleted from my app right after the user deletes an alarm entry in my app's database. I'm guessing that using different PendingIntent names would be the way to go, but I have no idea how to do this for each new alarm that a user creates. Thoughts on how to do this? Thanks!
See the same problem i faced here previously...
So the solution is to pass unique pending intent to the alarm service.. So here i how it can be done
PendingIntent pIntent = PendingIntent.getBroadcast(context, (int) alarm_id, intent, PendingIntent.FLAG_CANCEL_CURRENT);
here in the pending intent i have passed unique request id to the pending intent. Which you have to remember while cancelling the alarm.
So in my case what i have done to generate the unique id is put it in the database i have retrieved the id of the tables row and passed to the pending Intent.
So if you want to cancel the particular alarm you have to remember the same request id of the pending intent with the use of the same table entry...
I am sure it will work..
Use a different requestCode when registering each alarm. This is the second parameter of PendingIntent.getActivity/Service().
From the Android Documentation, cancel() will cancel all alarms with same pendingIntent. So the only way out is to create different pendingIntents. OR you could resort to scheduling repeating alarms as well, in this way you could use the same pendingIntents.
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.
I'm setting up alarms using this code
//in onCreate()
mAlarmManager = (AlarmManager) getApplicationContext()
.getSystemService(ALARM_SERVICE);
//called for each timer I schedule
Intent intent = new Intent (Intents.MY_INTENT_ACTION);
PendingIntent pendIntent = PendingIntent.getBroadcast(
getApplicationContext(), alert.getID(),
intent, PendingIntent.FLAG_ONE_SHOT);
long delay = 1000 * alert.getDuration();
Calendar cal = Calendar.getInstance();
mAlarmManager.set(AlarmManager.RTC_WAKEUP,
cal.getTimeInMillis() + delay, pendIntent);
But the behavior I'm seeing doesn't match what I should see in the documtation1,
public void set(int type, long triggerAtTime, PendingIntent operation)
If there is already an alarm scheduled for the same IntentSender, it will first be canceled...If there is already an alarm for this Intent scheduled (with the equality of two intents being defined by filterEquals(Intent)), then it will be removed and replaced by this one...
which suggests that calling set(int type, long triggetAtTime, PendingIntent operation) for an already alarmed intent should replace the old alarm for that intent. I'm not seeing any alarms get dropped. Instead, every alarm i set fires, despite the fact that the intents that are fired by the pending intents should all match (by filterEquals(intent)), since all I've set on each intent is an identical action.
Am I doing something wrong, or is the API not behaving as documented?
Note: changing the PendingIntent instantiation to
PendingIntent pendIntent = PendingIntent.getBroadcast(
getApplicationContext(), CONSTANT_ID,
intent, PendingIntent.FLAG_ONE_SHOT);
Behaves as expected, dropping any already set alarm, and replacing it with a new alarm.
Maybe it is because you are giving each alarm a different ID (Does alert.getID() give different ID's or not?). By the documentation, it shouldn't matter but yet you should still try.
If it doesn't work too, hold a reference for your last set alarm, and when you need it to be canceled, cancel it yourself then set the next one.
Have you tried with PendingIntent flag : PendingIntent.FLAG_UPDATE_CURRENT intead of PendingIntent.FLAG_ONE_SHOT?
It appears the consensus is that the documentation for AlarmManager.set(), as well as other AlarmManager methods claiming that Intents (not just the wrapping PendingIntents) are compared to check whether a particular alarm is already set.
Do not rely on AlarmManager matching Intents, instead rely on the matching of PendingIntents, which appears to be working as advertised.