Design Decisions in LightsOut

Here are some of the decisions that you faced in designing and implementing your LightsOut project:

1. This project involves "lights," among other things.
   Decision: What type of object should a light be?

2. When the program starts, a collection of 25 lights (5 by 5) must appear.
   • However, the user can increase or decrease the number of such lights while the program is running.
   
   Decision: What data structure should you use for this collection of lights?

3. You must display lights and controls.
   • The lights are to be displayed in a square grid.
   • The controls can be displayed however you think best.
   
   Decision: How do you want the controls to be displayed?
   Decision: How do you organize your project to allow the lights and controls to be displayed as you wish?

4. When the user selects a light, the neighbors of that light must toggle their states (on to off or vice versa).
   • In most designs, this means that one light must communicate with other lights.
   
   Decision: Does the light talk directly to its neighbors, or through a chain of other intermediate objects?
   • If the former, how does one light "get" its neighbors?
   • If the latter, what chain do you use and how does that chain of communication get established?

5. When the user presses a light, things should happen. That suggests asking the light to add a Listener.
   Decision: What type of Listener should you use?
   Decision: What object(s) should do the listening?

6. When the user selects a light, the neighbors of that light must toggle their states (on to off or vice versa). But:
   • Lights in the middle of the grid have four neighbors.
   • Lights on the edges of the grid have three neighbors.
   • Lights in the corners of the grid have two neighbors.
   
   Decision: How do you arrange that lights behave properly, regardless of where they are in the grid?

7. The five controls are similar in some ways, different in others.
   Decision: What class or classes should the controls be instances of?