/* * @(#)Areas.java 1.5 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.Area; import java.awt.geom.Ellipse2D; import java.awt.geom.GeneralPath; import javax.swing.*; /** * The Areas class demonstrates the CAG (Constructive Area Geometry) * operations: Add(union), Subtract, Intersect, and ExclusiveOR. */ public class Areas extends JApplet { public void init() { Demo demo = new Demo(); getContentPane().add(demo); getContentPane().add("North", new DemoControls(demo)); } /** * The Demo class performs the CAG operations and renders the shapes. */ public class Demo extends JPanel { public String areaType = "nop"; public Demo() { setBackground(Color.white); } public void drawDemo(int w, int h, Graphics2D g2) { GeneralPath p1 = new GeneralPath(); // draws the polygon on the left side p1.moveTo( w * .25f, 0.0f); p1.lineTo( w * .75f, h * .5f); p1.lineTo( w * .25f, (float) h); p1.lineTo( 0.0f, h * .5f); p1.closePath(); GeneralPath p2 = new GeneralPath(); // draws the polygon on the right side p2.moveTo( w * .75f, 0.0f); p2.lineTo( (float) w, h * .5f); p2.lineTo( w * .75f, (float) h); p2.lineTo( w * .25f, h * .5f); p2.closePath(); // creates an area object with the first path Area area = new Area(p1); g2.setColor(Color.yellow); /* * fills both paths if 'nop' is selected; otherwise, creates * an Area object with p2 and performs the selected CAG * operation with the two Area objects */ if (areaType.equals("nop")) { g2.fill(p1); g2.fill(p2); g2.setColor(Color.red); g2.draw(p1); g2.draw(p2); return; } else if (areaType.equals("add")) { area.add(new Area(p2)); } else if (areaType.equals("sub")) { area.subtract(new Area(p2)); } else if (areaType.equals("xor")) { area.exclusiveOr(new Area(p2)); } else if (areaType.equals("int")) { area.intersect(new Area(p2)); } else if (areaType.equals("pear")) { double sx = w/100; double sy = h/140; g2.scale(sx, sy); double x = w/sx/2; double y = h/sy/2; /* * creates the first leaf by filling the intersection of * two Area objects created from an ellipse. */ Ellipse2D leaf = new Ellipse2D.Double(x-16, y-29, 15.0, 15.0); Area leaf1 = new Area(leaf); leaf.setFrame(x-14, y-47, 30.0, 30.0); Area leaf2 = new Area(leaf); leaf1.intersect(leaf2); g2.setColor(Color.green); g2.fill(leaf1); // creates the second leaf. leaf.setFrame(x+1, y-29, 15.0, 15.0); leaf1 = new Area(leaf); leaf2.intersect(leaf1); g2.fill(leaf2); /* * creates the stem by filling the Area resulting from the * subtraction of two Area objects created from an * ellipse. */ Ellipse2D stem = new Ellipse2D.Double(x, y-42, 40.0, 40.0); Area st1 = new Area(stem); stem.setFrame(x+3, y-47, 50.0, 50.0); st1.subtract(new Area(stem)); g2.setColor(Color.black); g2.fill(st1); /* * creates the pear itself by filling the Area resulting * from the union of two Area objects created by two * different ellipses. */ Ellipse2D circle = new Ellipse2D.Double(x-25, y, 50.0, 50.0); Ellipse2D oval = new Ellipse2D.Double(x-19, y-20, 40.0, 70.0); Area circ = new Area(circle); circ.add(new Area(oval)); g2.setColor(Color.yellow); g2.fill(circ); return; } g2.fill(area); g2.setColor(Color.red); g2.draw(area); } 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); } } // End Demo class /** * The DemoControls class provides buttons for choosing * CAG operations as well as no CAG operations and multiple * CAG operations (pear). */ static class DemoControls extends JPanel implements ActionListener { Demo demo; JToolBar toolbar; JComboBox combo; public DemoControls(Demo demo) { this.demo = demo; setBackground(Color.gray); add(toolbar = new JToolBar()); toolbar.setFloatable(false); addTool("nop", "no area operation", true); addTool("add", "add", false); addTool("sub", "subtract", false); addTool("xor", "exclusiveOr", false); addTool("int", "intersection", false); addTool("pear", "pear", false); } public void addTool(String str, String tooltip, boolean state) { JButton b = (JButton) toolbar.add(new JButton(str)); b.setBackground(state ? Color.green : Color.lightGray); b.setToolTipText(tooltip); b.setSelected(state); b.addActionListener(this); } public void actionPerformed(ActionEvent e) { for (int i = 0; i < toolbar.getComponentCount(); i++) { JButton b = (JButton) toolbar.getComponentAtIndex(i); b.setBackground(Color.lightGray); } JButton b = (JButton) e.getSource(); b.setBackground(Color.green); demo.areaType = b.getText(); demo.repaint(); } } // End DemoControls class public static void main(String argv[]) { final Areas demo = new Areas(); demo.init(); Frame f = new Frame("Java 2D(TM) Demo - Areas"); f.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) {System.exit(0);} }); f.add(demo); f.pack(); f.setSize(new Dimension(400,300)); f.show(); } }