Making a Simulator for teaching oop

Hi Guys, So i’m trying to make this application that teaches Object Oriented Programming to students so as we all know the best way to learn oop is to visualize it so my idea is that in the tutorials when the user instances the object it shows in an simulated enviorment (will most likely be android) then we can teach the user about the properties by changing them and showing what are their effects. For example a traffic lights program simulation we can show the user about the cars attributes its methods such as forward, back, etc. So for this project ive kinda hit a roadblock from the start and would like some help and suggestions like the first problem that ive encountered how do i simulate in run time would greatly appreciate help. Thanks! 

I am attempting the very same thing. I am to teach Java OOP in class and online next semester for A community college. I am wondering how I can accomplish that here. Have you gotten a solution or an answer. Thanks so much.