Android - Delete or cancel notification before it shows up

Question

Let's say a notification using AlarmManager was set at a specific date. What if I want to delete that notification with a button press before it has even appeared. The NotificationManager.cancel(id) method if I'm not mistaken will cancel a notification that is currently showing. What if I want to delete it before it has even appeared? Like how you remove an item in an arraylist or how you delete a row in a database.

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Example I have a Person object with id,name and everytime I add a Person to the database, a Notification will be set on a specified date.

Here is the set notification method to be called with a calendar instance of a specified date and a person object:

 public void setNotification(Calendar calendar,Person person){
    AlarmManager alertManager = (AlarmManager)getSystemService(ALARM_SERVICE);
    Intent intent = new Intent();
    intent.setAction("android.media.action.DISPLAY_NOTIFICATION");
    intent.addCategory("android.intent.category.DEFAULT");
    intent.putExtra("myTag",person);

    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, person.getId(), intent, PendingIntent.FLAG_ONE_SHOT);
    alertManager.setExact(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);
}

My alarm receiver class (Yes I'm implementing DAO design pattern. I have a PersonDao and PersonDaoImpl with the latter being a singleton class):

public class AlarmReceiver extends BroadcastReceiver {
final static String GROUP_KEY = "GROUP_KEY";

@Override
public void onReceive(Context context, Intent intent) {
    //retrieve info:
    PersonDAO personDao = PersonDAOImpl.getInstance(context);
    Person person = (Person)intent.getSerializableExtra("myTag");
    String name = person.getName();
    long[] vibrationPattern = {0, 300, 0, 300};

    Intent notificationIntent = new Intent(context, MainActivity.class);
    TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
    stackBuilder.addParentStack(ViewDetails.class);
    stackBuilder.addNextIntent(notificationIntent);

    int requestCode = person.getId();
    PendingIntent pendingIntent = stackBuilder.getPendingIntent(requestCode, PendingIntent.FLAG_UPDATE_CURRENT);
NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
    Notification notification = builder.setContentTitle("Deadline due today")
            .setContentText("name: " + name)
            .setTicker(name+"'s debt is due today")
            .setSmallIcon(R.mipmap.ic_launcher)
            .setPriority(Notification.PRIORITY_MAX)

            .setContentIntent(pi)
            .build();

    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(requestCode, notification);


}

Example the date set on the alarm reciever was September 12 2016 3:00pm. The current date is Septermber 10 2016. What I want to do is when I delete the person in the database, the notification will be deleted/canceled also therefore on September 12 2016 3:00pm there will no longer be an alarm notification.

Answer 1

If you want to cancel something that you scheduled via AlarmManager , call cancel() on AlarmManager , passing in an equivalent PendingIntent to the one that you used to schedule the work in the first place. Here, by "equivalent PendingIntent ", I mean:

• the same operation (eg, getActivity() vs. getService() vs. getBroadcast() )
• the same request code (2nd parameter to those methods)
• an equivalent Intent

By "equivalent Intent ", I mean:

• the same component
• the same action
• the same MIME type
• the same categories
• the same data ( Uri )

for whatever of those properties you had set on the original Intent for the original PendingIntent .