append.java

please read it,you can

/*
 * @(#)Append.java	1.4	98/12/03
 *
 * Copyright 1998 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information
 * of Sun Microsystems, Inc. ("Confidential Information").  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with Sun.
 */


import java.awt.*;
import java.awt.event.*;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import javax.swing.*;


/**
 * The Append class appends a rectangle to a path with & without the connect.
 */
public class Append extends JApplet {

    public void init() { 
        setBackground(Color.white);
    }


    public void drawDemo(int w, int h, Graphics2D g2) {

        GeneralPath p = new GeneralPath(GeneralPath.WIND_NON_ZERO);
        p.moveTo(w*0.25f, h*0.2f);
        p.lineTo(w*0.75f, h*0.2f);
        p.closePath();

        /*
         * appends a rectangle to the path without displaying
         * the connecting line that connects to the previously
         * added path
         */
        p.append(new Rectangle2D.Double(w*.4, h*.3, w*.2, h*.1), false);
        g2.setColor(Color.gray);
        g2.fill(p);
        g2.setColor(Color.black);
        g2.draw(p);
        g2.drawString("Append rect to path", (int)(w*.25), (int)(h*.2)-5);

        // reset the path, p
        p.reset();

        p.moveTo(w*0.25f, h*0.6f);
        p.lineTo(w*0.75f, h*0.6f);
        p.closePath();

        /*
         * appends a rectangle to the path and displays the 
         * line that connects it to the previously added path
         */
        p.append(new Rectangle2D.Double(w*.4, h*.7, w*.2, h*.1), true);
        g2.setColor(Color.gray);
        g2.fill(p);
        g2.setColor(Color.black);
        g2.draw(p);
        g2.drawString("Append, connect", (int) (w*.25), (int) (h*.6)-5);
    }


    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
	Dimension d = getSize();
        g2.setBackground(getBackground());
        g2.clearRect(0, 0, d.width, d.height);
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        drawDemo(d.width, d.height, g2);
    }


    public static void main(String argv[]) {
        final Append demo = new Append();
        demo.init();
        JFrame f = new JFrame("Java 2D(TM) Demo - Append");
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {System.exit(0);}
        });
        f.getContentPane().add("Center", demo);
        f.pack();
        f.setSize(new Dimension(400,300));
        f.show();
    }
}