The way to do a notification.

README.md

Introduction

The way of using android notification.

notificaitonReceiver.java

public class MyBroadcastReceiver extends BroadcastReceiver
{
    public static final String BROADCAST_NAME = "sample.receiver";

    @Override
    public void onReceive(Context context, Intent intent)
    {
        Intent startIntent = this.isAppOnForeground(context) ?
            new Intent(RECEIVER_NAME) /* Send a msg to local receiver */ :
            new Intent(context, SampleActivity.class) /* Which activity you will start from */;

        // Put a argments.
        startIntent.putExtra("param1", "test parameter");

        if (this.isAppOnForeground(context))
        {
            // Send to specific activity with argments.
            context.sendBroadcast(startIntent);
        }
        else
        {
            // Start a activity as a new task.
            startIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(startIntent);
        }
    }

    private boolean isAppOnForeground(Context context)
    {
        ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
        if (appProcesses != null)
        {
            final String packageName = context.getPackageName();
            for (RunningAppProcessInfo appProcess : appProcesses)
            {
                if (appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND &&
                    appProcess.processName.equals(packageName))
                {
                    return true;
                }
            }
        }

        return false;
    }
}

notification.java

public static final String SAMPLE_BROADCAST = "sample.broadcast"
public static final String ARUG_PARAMETER = "param1"
public static final int NOTIFICATION_ID = 809;
public static final int BROADCAST_ID = 938;

private void showNotification() {
    // To SAMPLE_BROADCAST BroadcastReceiver.
    Intent intent = new Intent(SAMPLE_BROADCAST);
    intent.putExtra(ARUG_PARAMETER, "Hello World!");
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context
                                                        , NOTIFICATION_ID
                                                        , intent
                                                        , PendingIntent.FLAG_UPDATE_CURREN);

    // Create a notification.
    notification = createNotification();
    // Push a notification.
    ((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE))
                        .notify(NOTIFICATION_ID /* ID of notification */, notification);
}

private Notification createNotification() {
    return new NotificationCompat.Builder(context)
                                 .setSmallIcon(R.mipmap.sample_icon)
                                 .setContentTitle("Title")
                                 .setContentText("Body context")
                                 .setAutoCancel(true)
                                 .setPriority(NotificationCompat.PRIORITY_HIGH)
                                 .setDefaults(NotificationCompat.DEFAULT_VIBRATE)
                                 .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
                                 .setContentIntent(pendingIntent)
                                 .builde();
}

private Notification createUnclearableNotification() {
    return new NotificationCompat.Builder(context)
                                 .setSmallIcon(R.mipmap.sample_icon)
                                 .setContentTitle("Title")
                                 .setContentText("Body context")
                                 // Can't clearable flag.
                                 .setOngoing(true)
                                 .setPriority(NotificationCompat.PRIORITY_HIGH)
                                 .setContentIntent(pendingIntent)
                                 .build();
}