/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2007, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
 * USA.  
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------
 * PlumNeedle.java
 * ---------------
 * (C) Copyright 2002-2007, by the Australian Antarctic Division and 
 *                          Contributors.
 *
 * Original Author:  Bryan Scott (for the Australian Antarctic Division);
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * Changes:
 * --------
 * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
 * 27-Mar-2003 : Implemented Serializable (DG);
 * 09-Sep-2003 : Added equals() method (DG);
 * 08-Jun-2005 : Implemented Cloneable (DG);
 * 22-Nov-2007 : Implemented hashCode() (DG);
 *
 */

package org.jfree.chart.needle;

import java.awt.Graphics2D;
import java.awt.geom.Arc2D;
import java.awt.geom.Area;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

/**
 * A needle for use with the {@link org.jfree.chart.plot.CompassPlot} class.
 */
public class PlumNeedle extends MeterNeedle 
                        implements Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -3082660488660600718L;
    
    /**
     * Draws the needle.
     *
     * @param g2  the graphics device.
     * @param plotArea  the plot area.
     * @param rotate  the rotation point.
     * @param angle  the angle.
     */
    protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
                              Point2D rotate, double angle) {

        Arc2D shape = new Arc2D.Double(Arc2D.PIE);
        double radius = plotArea.getHeight();
        double halfX = plotArea.getWidth() / 2;
        double diameter = 2 * radius;

        shape.setFrame(plotArea.getMinX() + halfX - radius ,
                       plotArea.getMinY() - radius,
                       diameter, diameter);
        radius = Math.toDegrees(Math.asin(halfX / radius));
        shape.setAngleStart(270 - radius);
        shape.setAngleExtent(2 * radius);

        Area s = new Area(shape);

        if ((rotate != null) && (angle != 0)) {
            /// we have rotation houston, please spin me
            getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
            s.transform(getTransform());
        }

        defaultDisplay(g2, s);
    }
    
    /**
     * Tests another object for equality with this object.
     * 
     * @param obj  the object to test (<code>null</code> permitted).
     * 
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof PlumNeedle)) {
            return false;   
        }
        if (!super.equals(obj)) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code for this instance.
     * 
     * @return A hash code.
     */
    public int hashCode() {
        return super.hashCode();
    }

    /**
     * Returns a clone of this needle.
     * 
     * @return A clone.
     * 
     * @throws CloneNotSupportedException if the <code>PlumNeedle</code> 
     *     cannot be cloned (in theory, this should not happen).
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();   
    }

}
