    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     * 22-Nov-2007 : Implemented hashCode() (DG);
    043     *
    044     */
    045
    046    package org.jfree.chart.needle;
    047
    048    import java.awt.Graphics2D;
    049    import java.awt.geom.Arc2D;
    050    import java.awt.geom.Area;
    051    import java.awt.geom.Point2D;
    052    import java.awt.geom.Rectangle2D;
    053    import java.io.Serializable;
    054
    055    /**
    056     * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
    057     */
    058    public class PlumNeedle extends MeterNeedle
    059                            implements Cloneable, Serializable {
    060
    061        /** For serialization. */
    062        private static final long serialVersionUID = -3082660488660600718L;
    063
    064        /**
    065         * Draws the needle.
    066         *
    067         * @param g2  the graphics device.
    068         * @param plotArea  the plot area.
    069         * @param rotate  the rotation point.
    070         * @param angle  the angle.
    071         */
    072        protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea,
    073                                  Point2D rotate, double angle) {
    074
    075            Arc2D shape = new Arc2D.Double(Arc2D.PIE);
    076            double radius = plotArea.getHeight();
    077            double halfX = plotArea.getWidth() / 2;
    078            double diameter = 2 * radius;
    079
    080            shape.setFrame(plotArea.getMinX() + halfX - radius ,
    081                           plotArea.getMinY() - radius,
    082                           diameter, diameter);
    083            radius = Math.toDegrees(Math.asin(halfX / radius));
    084            shape.setAngleStart(270 - radius);
    085            shape.setAngleExtent(2 * radius);
    086
    087            Area s = new Area(shape);
    088
    089            if ((rotate != null) && (angle != 0)) {
    090                /// we have rotation houston, please spin me
    091                getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
    092                s.transform(getTransform());
    093            }
    094
    095            defaultDisplay(g2, s);
    096        }
    097
    098        /**
    099         * Tests another object for equality with this object.
    100         *
    101         * @param obj  the object to test (<code>null</code> permitted).
    102         *
    103         * @return A boolean.
    104         */
    105        public boolean equals(Object obj) {
    106            if (obj == this) {
    107                return true;
    108            }
    109            if (!(obj instanceof PlumNeedle)) {
    110                return false;
    111            }
    112            if (!super.equals(obj)) {
    113                return false;
    114            }
    115            return true;
    116        }
    117
    118        /**
    119         * Returns a hash code for this instance.
    120         *
    121         * @return A hash code.
    122         */
    123        public int hashCode() {
    124            return super.hashCode();
    125        }
    126
    127        /**
    128         * Returns a clone of this needle.
    129         *
    130         * @return A clone.
    131         *
    132         * @throws CloneNotSupportedException if the <code>PlumNeedle</code>
    133         *     cannot be cloned (in theory, this should not happen).
    134         */
    135        public Object clone() throws CloneNotSupportedException {
    136            return super.clone();
    137        }
    138
    139    }