001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006     *
007     * Project Info:  http://www.jfree.org/jfreechart/index.html
008     *
009     * This library is free software; you can redistribute it and/or modify it 
010     * under the terms of the GNU Lesser General Public License as published by 
011     * the Free Software Foundation; either version 2.1 of the License, or 
012     * (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but 
015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
017     * License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this library; if not, write to the Free Software
021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
022     * USA.  
023     *
024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * ---------------
028     * PlumNeedle.java
029     * ---------------
030     * (C) Copyright 2002-2005, by the Australian Antarctic Division and 
031     *                          Contributors.
032     *
033     * Original Author:  Bryan Scott (for the Australian Antarctic Division);
034     * Contributor(s):   David Gilbert (for Object Refinery Limited);
035     *
036     * $Id: PlumNeedle.java,v 1.4.2.2 2005/10/25 20:50:49 mungady Exp $
037     *
038     * Changes:
039     * --------
040     * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
041     * 27-Mar-2003 : Implemented Serializable (DG);
042     * 09-Sep-2003 : Added equals() method (DG);
043     * 08-Jun-2005 : Implemented Cloneable (DG);
044     *
045     */
046    
047    package org.jfree.chart.needle;
048    
049    import java.awt.Graphics2D;
050    import java.awt.geom.Arc2D;
051    import java.awt.geom.Area;
052    import java.awt.geom.Point2D;
053    import java.awt.geom.Rectangle2D;
054    import java.io.Serializable;
055    
056    /**
057     * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
058     *
059     * @author Bryan Scott
060     */
061    public class PlumNeedle extends MeterNeedle 
062                            implements Cloneable, Serializable {
063    
064        /** For serialization. */
065        private static final long serialVersionUID = -3082660488660600718L;
066        
067        /**
068         * Draws the needle.
069         *
070         * @param g2  the graphics device.
071         * @param plotArea  the plot area.
072         * @param rotate  the rotation point.
073         * @param angle  the angle.
074         */
075        protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
076                                  Point2D rotate, double angle) {
077    
078            Arc2D shape = new Arc2D.Double(Arc2D.PIE);
079            double radius = plotArea.getHeight();
080            double halfX = plotArea.getWidth() / 2;
081            double diameter = 2 * radius;
082    
083            shape.setFrame(plotArea.getMinX() + halfX - radius ,
084                           plotArea.getMinY() - radius,
085                           diameter, diameter);
086            radius = Math.toDegrees(Math.asin(halfX / radius));
087            shape.setAngleStart(270 - radius);
088            shape.setAngleExtent(2 * radius);
089    
090            Area s = new Area(shape);
091    
092            if ((rotate != null) && (angle != 0)) {
093                /// we have rotation houston, please spin me
094                getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
095                s.transform(getTransform());
096            }
097    
098            defaultDisplay(g2, s);
099        }
100        
101        /**
102         * Tests another object for equality with this object.
103         * 
104         * @param obj  the object to test (<code>null</code> permitted).
105         * 
106         * @return A boolean.
107         */
108        public boolean equals(Object obj) {
109            if (obj == this) {
110                return true;
111            }
112            if (!(obj instanceof PlumNeedle)) {
113                return false;   
114            }
115            if (!super.equals(obj)) {
116                return false;
117            }
118            return true;
119        }
120    
121        /**
122         * Returns a clone of this needle.
123         * 
124         * @return A clone.
125         */
126        public Object clone() throws CloneNotSupportedException {
127            return super.clone();   
128        }
129    
130    }