Java/2D Graphics GUI/XOR

Another XOR example

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class XORRectangles extends JPanel{
  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    // using white as the XOR color.
    g2.setXORMode(Color.white);
    // Paint a red rectangle.
    Rectangle2D r = new Rectangle2D.Double(50, 50, 150, 100);
    g2.setPaint(Color.red);
    g2.fill(r);
    g2.transform(AffineTransform.getTranslateInstance(25, 25));
    // Draw a blue rectangle.
    g2.setPaint(Color.blue);
    g2.fill(r);
  }
  
  public static void main(String[] args) {
    JFrame f = new JFrame();
    f.getContentPane().add(new XORRectangles());
    f.setSize(300, 200);
    f.setVisible(true);
  }
}

Layers - Try to use alpha values (transparency) to draw in layers

/*
 * Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
 * All rights reserved. Software written by Ian F. Darwin and others.
 * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS""
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
 * cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
 * pioneering role in inventing and promulgating (and standardizing) the Java 
 * language and environment is gratefully acknowledged.
 * 
 * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
 * inventing predecessor languages C and C++ is also gratefully acknowledged.
 */
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
/**
 * Layers - Try to use "alpha values (transparency) to draw in layers.
 * 
 * @author Ian Darwin, http://www.darwinsys.ru/
 * @version $Id: Layers.java,v 1.5 2004/02/09 03:33:49 ian Exp $
 */
public class Layers extends JFrame {
  int width, height;
  Layers(String s) {
    this(s, 400, 300);
  }
  Layers(String s, int w, int h) {
    setTitle(s);
    setSize(width = w, height = h); // a short form
    setBackground(Color.black);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
  }
  public void paint(Graphics g) {
    Color c1 = new Color(200, 100, 100, 50); // r, g, b, a
    Color c2 = new Color(100, 200, 000, 128);
    Color c3 = new Color(100, 200, 000, 255);
    g.setColor(c1);
    g.fillRect(0, 0, width / 2, height / 2);
    g.setColor(c2);
    g.fillRect(width / 4, height / 4, width / 2, height / 2);
    g.setColor(c3);
    g.fillRect(width / 3, height / 3, width / 4, height / 4);
  }
  public static void main(String[] a) {
    new Layers("Default Size").setVisible(true);
    new Layers("Smaller", 100, 100).setVisible(true);
  }
}