public class Location implements Cloneable {

	private double x;
	private double y;
	
	//-------------------------------
	public Location(double xInitial, double yInitial) {
		x = xInitial;
		y = yInitial;
	}
	
	public Location() {
		x = 0.0;
		y = 0.0;
	}
	
	//-------------------------------
	public Location clone() {
		Location answer;
		
		try {
			answer = (Location) super.clone();
		}
		catch (CloneNotSupportedException e) {
			throw new RuntimeException ("This class does not implement Cloneable.");
		}
		
		return answer;
	}
	
	//--------------------------------
	public boolean equals(Object obj) {
		if (obj instanceof Location) {
			Location candidate = (Location) obj;
			return (candidate.x == x) && (candidate.y == y);
		} else
			return false;
	}
	
	//--------------------------------
	public String toString() {
		return "(x=" + x + " y=" + y + ")";
	}
	
	//-------------------------------
	public static double distance(Location p1, Location p2) {
		double a, b, c_squared;
		
		if ((p1 == null) || (p2 == null)) 
			return Double.NaN;
		
		a = p1.x - p2.x;
		b = p1.y - p2.y;
		
		c_squared = a*a + b*b;
		
		return Math.sqrt(c_squared);
	}

	//--------------------------------
	public double getX() {
		return x;
	}
	
	//--------------------------------
	public double getY() {
		return y;
	}
	
	//--------------------------------
	public static Location midpoint(Location p1, Location p2) {
		double xMid, yMid;
		
		if ((p1 == null) || (p2 == null))
			return null;
		
		xMid = (p1.x/2) + ( p2.x/2);
		yMid = (p1.y/2) + ( p2.y/2);
		
		Location answer = new Location(xMid, yMid);
		return answer;
	}
	
	//--------------------------------
	public void rotate90() {
		double xNew;
		double yNew;
		
		xNew = y;
		yNew = -x;
		x = xNew;
		y = yNew;
	}
	
	//--------------------------------
	public void shift(double xAmount, double yAmount) {
		x += xAmount;
		y += yAmount;
	}
}