Clearing an ArrayList

Processing Libraries
6

by creating a boolen cleared you mean

  boolean cleared() {
    if (rings.size()==0) {
      return true;
    } else {
      return false;
    }
  }
  void display() {
    if (cleared()) {
      for (int i=rings.size()-1; i>0; i--) {
        Ring r=rings.get(i);
        r.update();
        r.display();
        if (r.isDead()) {
          rings.remove(i);
        }
      }
    }
  }