pointerneedle.java

这是一个segy数据显示程序

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, 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., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ------------------
 * PointerNeedle.java
 * ------------------
 * (C) Copyright 2002, 2003, by the Australian Antarctic Division and Contributors.
 *
 * Original Author:  Bryan Scott (for the Australian Antarctic Division);
 * Contributor(s):   David Gilbert (for Object Refinery Limited);
 *
 * $Id: PointerNeedle.java,v 1.5 2004/01/03 05:38:58 mungady Exp $
 *
 * Changes:
 * --------
 * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 09-Sep-2003 : Added equals(...) method (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;

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

    /**
     * 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 object  the object to test.
     * 
     * @return A boolean.
     */
    public boolean equals(Object object) {
        if (object == null) {
            return false;
        }
        if (object == this) {
            return true;
        }
        if (super.equals(object) && object instanceof PointerNeedle) {
            return true;
        }
        return false;
    }

}