Unable to check if alarm has been set by AlarmManager

Question

I am checking if the alarm has already been set by the AlarmManager using this answer .

Following is my code snippet.

boolean alarmUp = (PendingIntent.getBroadcast(MainActivity.this, 0,
    new Intent(MainActivity.this, AlarmReceiver.class), PendingIntent.FLAG_NO_CREATE) != null);
if (alarmUp) {
    // alarm is set; do some stuff
}

Intent alarmIntent = new Intent(MainActivity.this, AlarmReceiver.class);
final PendingIntent pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 0, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);

AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
manager.setInexactRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 10 * 1000, pendingIntent);

However, alarmUp is always being set as true. That is, whether I set the alarm or not, whenever I restart my app, it tell me that alarmUp is true (I am checking it by making a Toast ).

Please help where I am going wrong.

Answer 1

In order for this check to work, you need to be absolutely sure that the PendingIntent only exists when the alarm is set. There are 2 things you can do to ensure that is so:

1) When testing your code, make sure that you uninstall your application and then reinstall your application before testing it. Uninstalling your app will remove any PendingIntent s that your app might have created that are still pending.

2) When you cancel the alarm, make sure that you also cancel the PendingIntent . You can do this with

Intent alarmIntent = new Intent(MainActivity.this, AlarmReceiver.class);
final PendingIntent pendingIntent = 
          PendingIntent.getBroadcast(MainActivity.this, 0, alarmIntent,
          PendingIntent.FLAG_NO_CREATE);
if (pendingIntent != null) {
    pendingIntent.cancel();
}

Answer 2

Since API 21 you can use

public AlarmManager.AlarmClockInfo getNextAlarmClock ()

http://developer.android.com/reference/android/app/AlarmManager.html#getNextAlarmClock()

---

Now, the code that you are trying to use:

(PendingIntent.getBroadcast(MainActivity.this, 0,
    new Intent(MainActivity.this, AlarmReceiver.class), PendingIntent.FLAG_NO_CREATE) != null);

Bassically you are asking for a previus and existent intent called AlarmReceiver. But his AlarmReceiver refers to your own BroadcastReceiver.

As you can see in this line of the answer that you posted before:

boolean alarmUp = (PendingIntent.getBroadcast(context, 0, 
    new Intent("com.my.package.MY_UNIQUE_ACTION"), 
    PendingIntent.FLAG_NO_CREATE) != null);

They use "MY_UNIQUE_ACTION" to see if the intent exists.

Also in this site you can see a tutorial using that:

http://justcallmebrian.com/2010/04/27/using-alarmmanager-to-schedule-activities-on-android/

---

Unless you are able to access the android-system AlarmReceiver and see if the intent exists, you will not be able to ask for a 'generic' scheduled alarm. Is that what you are trying to do? If it's the case, are you sure that in case that you don't have any scheduled alarm the android-system AlarmReceiver intent was not created by the system anyway? Seems we don't have control to those components like we like to.

---

An working example: Manifest.xml:

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.blablabla.testa" > <uses-permission android:name="android.permission.WAKE_LOCK" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> <receiver android:name=".MySuperReceiver" android:label="MySuperReceiverName" /> </activity> </application> 

MySuperReceiver.java

package com.blablabla.testa;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;


public class MainActivity extends ActionBarActivity {

    public static final String TAG = "TEST APP:";

    AlarmManager alarmManager;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        GetAlarmService();
        CreateAlarm();
        CheckForAlarm();
        CancelAlarms();
        CheckForAlarm();
    }

    private void GetAlarmService()
    {
        alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
        Log.d(TAG, " GET Alarm Service ! ");
    }
    private void CreateAlarm()
    {
        long aroundInterval = 1*60*1000; 

        Intent intent = new Intent(getApplicationContext(), MySuperReceiver.class);
        intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//my custom string action name

        PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1001, intent, PendingIntent.FLAG_CANCEL_CURRENT);//used unique ID as 1001
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), aroundInterval, pendingIntent);//first start will start asap

        Log.d(TAG, " CREATE Alarm ! ");
    }

    private void CancelAlarms()
    {
        Intent intent = new Intent(getApplicationContext(), MySuperReceiver.class);//the same as up
        intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//the same as up
        PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1001, intent, PendingIntent.FLAG_CANCEL_CURRENT);//the same as up
        alarmManager.cancel(pendingIntent);//important
        pendingIntent.cancel();//important

        Log.d(TAG, " Cancel Alarm ! ");
    }

    private void CheckForAlarm()
    {
        //checking if alarm is working with pendingIntent #3
        Intent intent = new Intent(getApplicationContext()  , MySuperReceiver.class);//the same as up
        intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//the same as up
        boolean isWorking = (PendingIntent.getBroadcast(getApplicationContext() , 1001, intent, PendingIntent.FLAG_NO_CREATE) != null);//just changed the flag
        Log.d("TAG: TEST APP:  ", "alarm is " + (isWorking ? "" : "not") + " working...");

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

And MainActivity.java:

 package com.blablabla.testa; import android.app.AlarmManager; import android.app.PendingIntent; import android.content.Context; import android.content.Intent; import android.support.v7.app.ActionBarActivity; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.MenuItem; public class MainActivity extends ActionBarActivity { public static final String TAG = "TEST APP:"; AlarmManager alarmManager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); GetAlarmService(); CreateAlarm(); CheckForAlarm(); CancelAlarms(); CheckForAlarm(); } private void GetAlarmService() { alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE); Log.d(TAG, " GET Alarm Service ! "); } private void CreateAlarm() { long aroundInterval = 1*60*1000; Intent intent = new Intent(getApplicationContext(), MySuperReceiver.class); intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//my custom string action name PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1001, intent, PendingIntent.FLAG_CANCEL_CURRENT);//used unique ID as 1001 alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), aroundInterval, pendingIntent);//first start will start asap Log.d(TAG, " CREATE Alarm ! "); } private void CancelAlarms() { Intent intent = new Intent(getApplicationContext(), MySuperReceiver.class);//the same as up intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//the same as up PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1001, intent, PendingIntent.FLAG_CANCEL_CURRENT);//the same as up alarmManager.cancel(pendingIntent);//important pendingIntent.cancel();//important Log.d(TAG, " Cancel Alarm ! "); } private void CheckForAlarm() { //checking if alarm is working with pendingIntent #3 Intent intent = new Intent(getApplicationContext() , MySuperReceiver.class);//the same as up intent.setAction(MySuperReceiver.ACTION_ALARM_RECEIVER);//the same as up boolean isWorking = (PendingIntent.getBroadcast(getApplicationContext() , 1001, intent, PendingIntent.FLAG_NO_CREATE) != null);//just changed the flag Log.d("TAG: TEST APP: ", "alarm is " + (isWorking ? "" : "not") + " working..."); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }