001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 2002-2007, 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 * Changes:
037 * --------
038 * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
039 * 27-Mar-2003 : Implemented Serializable (DG);
040 * 09-Sep-2003 : Added equals() method (DG);
041 * 08-Jun-2005 : Implemented Cloneable (DG);
042 *
043 */
044
045package org.jfree.chart.needle;
046
047import java.awt.Graphics2D;
048import java.awt.geom.Arc2D;
049import java.awt.geom.Area;
050import java.awt.geom.Point2D;
051import java.awt.geom.Rectangle2D;
052import java.io.Serializable;
053
054/**
055 * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
056 */
057public class PlumNeedle extends MeterNeedle 
058                        implements Cloneable, Serializable {
059
060    /** For serialization. */
061    private static final long serialVersionUID = -3082660488660600718L;
062    
063    /**
064     * Draws the needle.
065     *
066     * @param g2  the graphics device.
067     * @param plotArea  the plot area.
068     * @param rotate  the rotation point.
069     * @param angle  the angle.
070     */
071    protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
072                              Point2D rotate, double angle) {
073
074        Arc2D shape = new Arc2D.Double(Arc2D.PIE);
075        double radius = plotArea.getHeight();
076        double halfX = plotArea.getWidth() / 2;
077        double diameter = 2 * radius;
078
079        shape.setFrame(plotArea.getMinX() + halfX - radius ,
080                       plotArea.getMinY() - radius,
081                       diameter, diameter);
082        radius = Math.toDegrees(Math.asin(halfX / radius));
083        shape.setAngleStart(270 - radius);
084        shape.setAngleExtent(2 * radius);
085
086        Area s = new Area(shape);
087
088        if ((rotate != null) && (angle != 0)) {
089            /// we have rotation houston, please spin me
090            getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
091            s.transform(getTransform());
092        }
093
094        defaultDisplay(g2, s);
095    }
096    
097    /**
098     * Tests another object for equality with this object.
099     * 
100     * @param obj  the object to test (<code>null</code> permitted).
101     * 
102     * @return A boolean.
103     */
104    public boolean equals(Object obj) {
105        if (obj == this) {
106            return true;
107        }
108        if (!(obj instanceof PlumNeedle)) {
109            return false;   
110        }
111        if (!super.equals(obj)) {
112            return false;
113        }
114        return true;
115    }
116
117    /**
118     * Returns a clone of this needle.
119     * 
120     * @return A clone.
121     * 
122     * @throws CloneNotSupportedException if the <code>PlumNeedle</code> 
123     *     cannot be cloned (in theory, this should not happen).
124     */
125    public Object clone() throws CloneNotSupportedException {
126        return super.clone();   
127    }
128
129}