Point.java

/*******************************************************************************
 * Copyright (c) 2000, 2010, 2012 IBM Corporation, Gerhardt Informatics Kft. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Gerhardt Informatics Kft. - GEFGWT port
 *******************************************************************************/
package org.eclipse.swt.graphics;

import org.eclipse.swt.internal.SerializableCompatibility;

/**
 * Instances of this class represent places on the (x, y) coordinate plane.
 * <p>
 * The coordinate space for rectangles and points is considered to have
 * increasing values downward and to the right from its origin making this the
 * normal, computer graphics oriented notion of (x, y) coordinates rather than
 * the strict mathematical one.
 * </p>
 * <p>
 * The hashCode() method in this class uses the values of the public fields to
 * compute the hash value. When storing instances of the class in hashed
 * collections, do not modify these fields after the object has been inserted.
 * </p>
 * <p>
 * Application code does <em>not</em> need to explicitly release the resources
 * managed by each instance when those instances are no longer required, and
 * thus no <code>dispose()</code> method is provided.
 * </p>
 * 
 * @see Rectangle
 * @see <a href="http://www.eclipse.org/swt/">Sample code and further
 *      information</a>
 */

public final class Point implements SerializableCompatibility {

	/**
	 * the x coordinate of the point
	 */
	public int x;

	/**
	 * the y coordinate of the point
	 */
	public int y;

	static final long serialVersionUID = 3257002163938146354L;

	/**
	 * Constructs a new point with the given x and y coordinates.
	 * 
	 * @param x
	 *            the x coordinate of the new point
	 * @param y
	 *            the y coordinate of the new point
	 */
	public Point(int x, int y) {
		this.x = x;
		this.y = y;
	}

	/**
	 * Compares the argument to the receiver, and returns true if they represent
	 * the <em>same</em> object using a class specific comparison.
	 * 
	 * @param object
	 *            the object to compare with this object
	 * @return <code>true</code> if the object is the same as this object and
	 *         <code>false</code> otherwise
	 * 
	 * @see #hashCode()
	 */
	public boolean equals(Object object) {
		if (object == this)
			return true;
		if (!(object instanceof Point))
			return false;
		Point p = (Point) object;
		return (p.x == this.x) && (p.y == this.y);
	}

	/**
	 * Returns an integer hash code for the receiver. Any two objects that
	 * return <code>true</code> when passed to <code>equals</code> must return
	 * the same value for this method.
	 * 
	 * @return the receiver's hash
	 * 
	 * @see #equals(Object)
	 */
	public int hashCode() {
		return x ^ y;
	}

	/**
	 * Returns a string containing a concise, human-readable description of the
	 * receiver.
	 * 
	 * @return a string representation of the point
	 */
	public String toString() {
		return "Point {" + x + ", " + y + "}"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}

}