Simulator.java

import java.util.Random;
import java.util.List;
import java.util.ArrayList;
import java.awt.Color;

/**
 * A simple predator-prey simulator, based on a field containing rabbits and foxes.
 */
public class Simulator
{
	/* Constants representing configuration information for the simulation. */

	private static final int    DEFAULT_HEIGHT = 50; //size of field by default
	private static final int    DEFAULT_WIDTH  = 50; 
	private static final double FOX_CREATION_PROBABILITY = 0.02;
	private static final double RABBIT_CREATION_PROBABILITY = 0.08;    

	/* Instance variables */

	private Field field;
	private int   step;
	
	private SimulatorView view; //graphical view of the Simulator, don't mess with this

	/**
	 * Construct a simulation field with default size.
	 */
	public Simulator()
	{
		//TODO
	}

	/**
	 * Create a simulation field with the given size.
	 * @param height Depth of the field. Must be greater than zero.
	 * @param width Width of the field. Must be greater than zero.
	 */
	public Simulator(int height, int width)
	{
		/*
		 * TODO
		 */
		
		// Create a view of the state of each location in the field, don't mess with this
		view = new SimulatorView(height, width);
		view.setColor(Rabbit.class, Color.orange);
		view.setColor(Fox.class, Color.blue);

		// Setup a valid starting point, don't mess with this
		reset();
	}

	/**
	 * Run the simulation from its current state for a reasonably long period,
	 * e.g. 500 steps.
	 */
	public void runLongSimulation()
	{
		simulate(500);
	}

	/**
	 * Run the simulation from its current state for the given number of steps.
	 * Stop before the given number of steps if it ceases to be viable.
	 * @param numSteps The number of steps to run for.
	 */
	public void simulate(int numSteps)
	{
		for (int step = 1; step <= numSteps && view.isViable(field); step++) {
			simulateOneStep();
		}
	}
	
	/**
	 * Run the simulation from its current state for a single step.
	 * Iterate over the whole field updating the state of each
	 * fox and rabbit.
	 */
	public void simulateOneStep()
	{
		try { Thread.sleep(100); } catch (Exception e) {} // Slow it down a bit, don't remove

		/*
		 * TODO
		 */
		
		view.showStatus(step, field); // Display the new field on screen, don't remove
	}

	/**
	 * Reset the simulation to a starting position.
	 */
	public void reset()
	{
		step = 0;
		
		field.clear();
		
		this.populate();

		// Show the starting state in the view
		view.showStatus(step, field);
	}

	/**
	 * Populate a field with foxes and rabbits.
	 */
	private void populate()
	{
		//TODO
	}
}