I recently decided to attempt creating a simple game in Processing, then decided to ask the forums to see what you guys thought of the way I was going.
To implement different "rooms" or "screens" - for example, a menu screen then a main gameplay screen - I had a Room class, a Room controller, and an Entity class. Each Room had a certain number of Entities in an ArrayList, and each Room was in an ArrayList of Rooms which were controlled by the Room controller. The Room controller had methods such as nextRoom, etc.
I couldn't help but wonder if there is a better and more "Processing-like" solution to this problem.