title: How to implement Android Notification with overview like WhatsApp?
body: <p>I want to <strong>implement a notification</strong> with <strong>overview</strong> when the device is in use like WhatsApp:</p>
  
  <p><a href="https://i.stack.imgur.com/1eXIo.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1eXIo.jpg" alt="enter image description here"></a></p>
  
  <p>I know the basic implementation this way:</p>
  
  <pre><code>PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, 
      new Intent(this, MainActivity.class), 0);
  
  Notification notification = new Notification.Builder(this)
                  .setContentTitle("Title")
                  .setContentText("Message")
                  .setSmallIcon(R.drawable.ic_notif)
                  .setContentIntent(mPendingIntent)
                  .build();
  
  NotificationManager notificationManager = 
      (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
  notificationManager.notify(1, notification);
  </code></pre>
  
  <p>But in that case, I don't have the overview. I only have a small icon in the notification bar:</p>
  
  <p><a href="https://i.stack.imgur.com/o1dlZ.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o1dlZ.gif" alt="Simple Notification"></a></p>