Onesignal: Resume last Activity when opening a Notification

onesignal-resume-last-activity-when-opening-a-notification.java

// Add the following code to the top of onCreate in your launcher Activity.
// ---
// By default OneSignal calls startActivity with the following intent flags:
// Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK

private static boolean activityStarted;

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  if (   activityStarted
      && getIntent() != null
      && (getIntent().getFlags() & Intent.FLAG_ACTIVITY_REORDER_TO_FRONT) != 0) {
  	finish();
  	return;
  }
  
  activityStarted = true;
}