I am looking for a way to create a preference
in Settings
to send a notification at a specific time of the day (set by user in settings) in an Andr
After looking at different posts and some research on AlarmManager
implementation, this is what worked for me.
The base for this is this post and Schedule repeating Alarms Android Documentation.
This is my current implementation:
I have a SwitchPreference
and a TimePicker
implementation is Settings
SwitchPreference to ask if user wants to enable Repeating Daily Notifications.
TimePicker to set the Notification time.
In MainActivity
's OnCreate
method or wherever you are reading the SharedPreferences
do this:
PreferenceManager.setDefaultValues(this, R.xml.preferences, false);
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
Boolean dailyNotify = sharedPref.getBoolean(SettingsActivity.KEY_PREF_DAILY_NOTIFICATION, true);
PackageManager pm = this.getPackageManager();
ComponentName receiver = new ComponentName(this, DeviceBootReceiver.class);
Intent alarmIntent = new Intent(this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);
AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
// if user enabled daily notifications
if (dailyNotify) {
//region Enable Daily Notifications
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, sharedPref.getInt("dailyNotificationHour", 7));
calendar.set(Calendar.MINUTE, sharedPref.getInt("dailyNotificationMin", 15));
calendar.set(Calendar.SECOND, 1);
// if notification time is before selected time, send notification the next day
if (calendar.before(Calendar.getInstance())) {
calendar.add(Calendar.DATE, 1);
}
if (manager != null) {
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);
}
}
//To enable Boot Receiver class
pm.setComponentEnabledSetting(receiver,
PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
PackageManager.DONT_KILL_APP);
//endregion
} else { //Disable Daily Notifications
if (PendingIntent.getBroadcast(this, 0, alarmIntent, 0) != null && manager != null) {
manager.cancel(pendingIntent);
//Toast.makeText(this,"Notifications were disabled",Toast.LENGTH_SHORT).show();
}
pm.setComponentEnabledSetting(receiver,
PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
PackageManager.DONT_KILL_APP);
}
Next add AlarmReceiver
class that implements BroadcastReceiver
like this:
public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(Objects.requireNonNull(context));
SharedPreferences.Editor sharedPrefEditor = prefs.edit();
NotificationManager nm = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
Intent notificationIntent = new Intent(context, MainActivity.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP
| Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent pendingI = PendingIntent.getActivity(context, 0,
notificationIntent, 0);
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
NotificationChannel channel = new NotificationChannel("default",
"Daily Notification",
NotificationManager.IMPORTANCE_DEFAULT);
channel.setDescription("Daily Notification");
if (nm != null) {
nm.createNotificationChannel(channel);
}
}
NotificationCompat.Builder b = new NotificationCompat.Builder(context, "default");
b.setAutoCancel(true)
.setDefaults(NotificationCompat.DEFAULT_ALL)
.setWhen(System.currentTimeMillis())
.setSmallIcon(R.mipmap.ic_launcher_foreground)
.setTicker("{Time to watch some cool stuff!}")
.setContentTitle("My Cool App")
.setContentText("Time to watch some cool stuff!")
.setContentInfo("INFO")
.setContentIntent(pendingI);
if (nm != null) {
nm.notify(1, b.build());
Calendar nextNotifyTime = Calendar.getInstance();
nextNotifyTime.add(Calendar.DATE, 1);
sharedPrefEditor.putLong("nextNotifyTime", nextNotifyTime.getTimeInMillis());
sharedPrefEditor.apply();
}
}
}
The system will turn off the AlarmManager
if Device is powered off or reboots, so restart it again on BOOT COMPLETE
add this class:
public class DeviceBootReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
if (Objects.equals(intent.getAction(), "android.intent.action.BOOT_COMPLETED")) {
// on device boot complete, reset the alarm
Intent alarmIntent = new Intent(context, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, 0);
AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
final SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(Objects.requireNonNull(context));
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.set(Calendar.HOUR_OF_DAY, sharedPref.getInt("dailyNotificationHour", 7));
calendar.set(Calendar.MINUTE, sharedPref.getInt("dailyNotificationMin", 15));
calendar.set(Calendar.SECOND, 1);
Calendar newC = new GregorianCalendar();
newC.setTimeInMillis(sharedPref.getLong("nextNotifyTime", Calendar.getInstance().getTimeInMillis()));
if (calendar.after(newC)) {
calendar.add(Calendar.HOUR, 1);
}
if (manager != null) {
manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
AlarmManager.INTERVAL_DAY, pendingIntent);
}
}
}
}
And Finally do not forget to add these permissions to AndroidManidest
:
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
and register your receivers in AndroidManifest
<application
<!--YOUR APPLICATION STUFF-->
<receiver android:name=".DeviceBootReceiver"
android:enabled="false">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<receiver android:name=".AlarmReceiver" />
The Notification
should be set by this at a specific time of the day specified by TimePicker
and if user enabled the SwitchPreference
.
There are tons of examples of how to do this on StackOverflow, but unfortunately none of them work anymore because Google changed how the AlarmManager works.
The only AlarmManager option that allows a developer to wakeup a device at a specific time is AlarmManager.setAlarmClock.
Using setAlarmClock
In addition to the alarm, you can set an intent that will enable you to launch your app when the alarm is clicked.
The device can also be awoken at a specific time using a high priority FCM, Firebase Cloud Message.
But in summary, there is no other option: 'setExact' and associated methods no longer work as the name advertises.