Point.java

package ca.ubc.cs.spl.aspectPatterns.examples.observer.java;

/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This file is part of the design patterns project at UBC
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is ca.ubc.cs.spl.aspectPatterns.
 * 
 * For more details and the latest version of this code, please see:
 * http://www.cs.ubc.ca/labs/spl/projects/aodps.html
 *
 * Contributor(s):   
 */


import java.awt.Color;
import java.util.HashSet;
import java.util.Iterator;

/**
 * Represents a point with x and y coordinates and a color.
 *
 * @author  Jan Hannemann
 * @author  Gregor Kiczales
 * @version 1.11, 04/01/04
 */
 
public class Point implements ChangeSubject { 
    
    /**
     * stores the <i>Observer</i>s for this point (<i>Subject</i>)
     */
         
    private HashSet observers;

    /**
     * the point's x-coordinate
     */
         
    private int x;
    
    /**
     * the point's y-coordinate
     */
    
    private int y;
    
    /** 
     * the point's current color
     */
     
    private Color color;
    
    /**
     * Creates a new point object based on x and y coordinates and color.
     */
    
    public Point(int x, int y, Color color) {
    	this.x = x;
	    this.y = y;
    	this.color=color; 
    	this.observers = new HashSet();
    }
    
    /**
     * Returns the point's current x-coordinate.
     *
     * @return the current x-coordinate
     */

    public int getX() { 
    	return x; 
    }

    /**
     * Returns the point's current y-coordinate.
     *
     * @return the current y-coordinate
     */

    public int getY() { 
    	return y; 
    }
    
    /**
     * Sets the current x-coordinate.
     *
     * @param x the new x-coordinate
     */

    public void setX(int x) { 
        this.x = x; 
        notifyObservers();
    }

    /**
     * Sets the current y-coordinate.
     *
     * @param y the new y-coordinate
     */

    public void setY(int y) { 
        this.y = y; 
        notifyObservers();
    }

    /**
     * Returns the point's current color.
     *
     * @return the current color
     */

    public Color getColor() { return color; }

    /**
     * Sets the current color.
     *
     * @param color the new color
     */

    public void setColor(Color color) { 
        this.color = color; 
        notifyObservers();
    }      
    
    
	/**
	 * Attaches an <i>Observer</i> to this <i>Subject</i>.
	 * 
	 * @param o the <i>Observer</i> to attach
	 */
     
    public void addObserver(ChangeObserver o) {
        this.observers.add(o);
    }
    
	/**
	 * Detaches an <i>Observer</i> from this <i>Subject</i>.
	 * 
	 * @param o the <i>Observer</i> to detach
	 */
     
    public void removeObserver(ChangeObserver o) {
        this.observers.remove(o);
    }
    
	/**
	 * Notifies all <i>Observer</i>s.
	 */
   
    public void notifyObservers() {
        for (Iterator e = observers.iterator() ; e.hasNext() ;) {
            ((ChangeObserver)e.next()).refresh(this);
        }
    }
}