jfreechart example source code file (PointerNeedle.java)

This example jfreechart source code file (PointerNeedle.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jfreechart tags/keywords

awt, cloneable, clonenotsupportedexception, clonenotsupportedexception, generalpath, generalpath, geometry, io, meterneedle, object, object, point2d, pointerneedle, pointerneedle, rectangle2d, serializable

The jfreechart PointerNeedle.java source code

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, 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.]
 *
 * ------------------
 * PointerNeedle.java
 * ------------------
 * (C) Copyright 2002-2008, 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);
 * 26-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.GeneralPath;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;

/**
 * A needle in the shape of a pointer, for use with the
 * {@link org.jfree.chart.plot.CompassPlot} class.
 */
public class PointerNeedle extends MeterNeedle
                           implements Cloneable, Serializable {

    /** For serialization. */
    private static final long serialVersionUID = -4744677345334729606L;

    /**
     * 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) {

        GeneralPath shape1 = new GeneralPath();
        GeneralPath shape2 = new GeneralPath();
        float minX = (float) plotArea.getMinX();
        float minY = (float) plotArea.getMinY();
        float maxX = (float) plotArea.getMaxX();
        float maxY = (float) plotArea.getMaxY();
        float midX = (float) (minX + (plotArea.getWidth() / 2));
        float midY = (float) (minY + (plotArea.getHeight() / 2));

        shape1.moveTo(minX, midY);
        shape1.lineTo(midX, minY);
        shape1.lineTo(maxX, midY);
        shape1.closePath();

        shape2.moveTo(minX, midY);
        shape2.lineTo(midX, maxY);
        shape2.lineTo(maxX, midY);
        shape2.closePath();

        if ((rotate != null) && (angle != 0)) {
            /// we have rotation huston, please spin me
            getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
            shape1.transform(getTransform());
            shape2.transform(getTransform());
        }

        if (getFillPaint() != null) {
            g2.setPaint(getFillPaint());
            g2.fill(shape1);
        }

        if (getHighlightPaint() != null) {
            g2.setPaint(getHighlightPaint());
            g2.fill(shape2);
        }

        if (getOutlinePaint() != null) {
            g2.setStroke(getOutlineStroke());
            g2.setPaint(getOutlinePaint());
            g2.draw(shape1);
            g2.draw(shape2);
        }
    }

    /**
     * Tests another object for equality with this object.
     *
     * @param obj  the object to test (<code>null permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (!(obj instanceof PointerNeedle)) {
            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>PointerNeedle
     *     cannot be cloned (in theory, this should not happen).
     */
    public Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

}