Android: Alarm, Broadcast Receiver and Notification Sample

NOTES in the below diagram is SELF-EXPLANTORY

MainActivity.java

package isquarebsys.training;

import android.app.AlarmManager;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;

import broadcast.UtilityReceiver;

public class MainActivity extends AppCompatActivity {
    private final static String TAG="MainActivity";
    private int alarmNotificationId=1;
    long timeForAlarmInMilliSecs=10;
    long timeToRepeatAlarmInMilliSecs=5;

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

    }

    public void sendNotification(View view){
        NotificationCompat.Builder builder =
                new NotificationCompat.Builder(this)
                        .setSmallIcon(R.mipmap.ic_launcher)
                        .setContentTitle("Notifications Example")
                        .setContentText("This is a test notification");

        Intent notificationIntent = new Intent(this, MainActivity.class);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);
        builder.setContentIntent(contentIntent);
        builder.addAction(new NotificationCompat.Action(R.mipmap.ic_launcher,"Cancel",contentIntent));
        Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        builder.setSound(uri);
        builder.setStyle(new NotificationCompat.BigTextStyle().bigText("Big View Styles"));

        // Add as notification        NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        manager.notify(0, builder.build());


    }

    /**     * https://stackoverflow.com/questions/30075196/how-can-i-cancel-unshown-notifications-in-android     * @param view     */
    public void setAlarm(View view){
        Intent notificationIntent = new Intent(getApplicationContext(), UtilityReceiver.class);
        // Use a Pending Intent to Launch the Alarm        // alarmNotificationId is the key to cancel the original alarm        PendingIntent notificationPendingIntent = PendingIntent.getBroadcast(getApplicationContext(),
                alarmNotificationId, notificationIntent, 0);
        AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
//        alarmManager.set(AlarmManager.RTC_WAKEUP,timeForAlarmInMilliSecs, notificationPendingIntent);        // Schedule in 5 secs and repeat every 5 secs        alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() + timeToRepeatAlarmInMilliSecs,
                timeToRepeatAlarmInMilliSecs,notificationPendingIntent);
    }

    /**     * 1. https://stackoverflow.com/questions/30075196/how-can-i-cancel-unshown-notifications-in-android [does NOT WORK]     * 2. http://android-er.blogspot.in/2012/05/cancel-alarm-with-matching.html [Works]     *     * Alarm CAN NOT be cancelled after it happened. It can be CANCELLED only before it happens but AFTER scheduling     * To TEST, click sendAlarm and cancel before it happens    * @param view     */    public void cancelAlarm(View view){
        Intent notificationIntent = new Intent(getApplicationContext(), UtilityReceiver.class);
        // Use a Pending Intent to Launch the Alarm        // alarmNotificationId is the key to cancel the original alarm        PendingIntent notificationPendingIntent = PendingIntent.getBroadcast(getApplicationContext(),
                alarmNotificationId, notificationIntent, 0);
        AlarmManager alarmManager = (AlarmManager) getApplicationContext().getSystemService(Context.ALARM_SERVICE);
        alarmManager.cancel(notificationPendingIntent);
    }
}

UtilityReceiver.java

package broadcast;

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.media.RingtoneManager;
import android.net.Uri;
import android.support.v4.app.NotificationCompat;

import isquarebsys.training.R;

public class UtilityReceiver extends BroadcastReceiver {
    @Override    public void onReceive(Context context, Intent intent) {
        int notificationId = (int) System.currentTimeMillis();
        PendingIntent pendingIntent = PendingIntent.getActivity(context, notificationId, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Alarm Notification")
                .setContentIntent(pendingIntent)
                .setContentText("Alarm")
                .setAutoCancel(true);
        Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        mBuilder.setSound(uri);
        NotificationManager mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        mNotificationManager.notify(notificationId, mBuilder.build());
    }
}