    001/* ===========================================================
    002 * JFreeChart : a free chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C) Copyright 2000-2011, 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 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    025 * Other names may be trademarks of their respective owners.]
    026 *
    027 * ----------------
    028 * ArrowNeedle.java
    029 * ----------------
    030 * (C) Copyright 2002-2008, 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 : Added hashCode() implementation (DG);
    043 *
    044 */
    045
    046package org.jfree.chart.needle;
    047
    048import java.awt.Graphics2D;
    049import java.awt.Shape;
    050import java.awt.geom.GeneralPath;
    051import java.awt.geom.Line2D;
    052import java.awt.geom.Point2D;
    053import java.awt.geom.Rectangle2D;
    054import java.io.Serializable;
    055
    056import org.jfree.chart.HashUtilities;
    057
    058/**
    059 * A needle in the shape of an arrow.
    060 */
    061public class ArrowNeedle extends MeterNeedle
    062                         implements Cloneable, Serializable {
    063
    064    /** For serialization. */
    065    private static final long serialVersionUID = -5334056511213782357L;
    066
    067    /**
    068     * A flag controlling whether or not there is an arrow at the top of the
    069     * needle.
    070     */
    071    private boolean isArrowAtTop = true;
    072
    073    /**
    074     * Constructs a new arrow needle.
    075     *
    076     * @param isArrowAtTop  a flag that controls whether or not there is an
    077     *                      arrow at the top of the needle.
    078     */
    079    public ArrowNeedle(boolean isArrowAtTop) {
    080        this.isArrowAtTop = isArrowAtTop;
    081    }
    082
    083    /**
    084     * Draws the needle.
    085     *
    086     * @param g2  the graphics device.
    087     * @param plotArea  the plot area.
    088     * @param rotate  the rotation point.
    089     * @param angle  the angle.
    090     */
    091    protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea,
    092                              Point2D rotate, double angle) {
    093
    094        Line2D shape = new Line2D.Float();
    095        Shape d = null;
    096
    097        float x = (float) (plotArea.getMinX() +  (plotArea.getWidth() / 2));
    098        float minY = (float) plotArea.getMinY();
    099        float maxY = (float) plotArea.getMaxY();
    100        shape.setLine(x, minY, x, maxY);
    101
    102        GeneralPath shape1 = new GeneralPath();
    103        if (this.isArrowAtTop) {
    104            shape1.moveTo(x, minY);
    105            minY += 4 * getSize();
    106        }
    107        else {
    108            shape1.moveTo(x, maxY);
    109            minY = maxY - 4 * getSize();
    110        }
    111        shape1.lineTo(x + getSize(), minY);
    112        shape1.lineTo(x - getSize(), minY);
    113        shape1.closePath();
    114
    115        if ((rotate != null) && (angle != 0)) {
    116            getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
    117            d = getTransform().createTransformedShape(shape);
    118        }
    119        else {
    120            d = shape;
    121        }
    122        defaultDisplay(g2, d);
    123
    124        if ((rotate != null) && (angle != 0)) {
    125            d = getTransform().createTransformedShape(shape1);
    126        }
    127        else {
    128            d = shape1;
    129        }
    130        defaultDisplay(g2, d);
    131
    132    }
    133
    134    /**
    135     * Tests another object for equality with this object.
    136     *
    137     * @param obj  the object to test (<code>null</code> permitted).
    138     *
    139     * @return A boolean.
    140     */
    141    public boolean equals(Object obj) {
    142        if (obj == this) {
    143            return true;
    144        }
    145        if (!(obj instanceof ArrowNeedle)) {
    146            return false;
    147        }
    148        if (!super.equals(obj)) {
    149            return false;
    150        }
    151        ArrowNeedle that = (ArrowNeedle) obj;
    152        if (this.isArrowAtTop != that.isArrowAtTop) {
    153            return false;
    154        }
    155        return true;
    156    }
    157
    158    /**
    159     * Returns a hash code for this instance.
    160     *
    161     * @return A hash code.
    162     */
    163    public int hashCode() {
    164        int result = super.hashCode();
    165        result = HashUtilities.hashCode(result, this.isArrowAtTop);
    166        return result;
    167    }
    168
    169    /**
    170     * Returns a clone of this needle.
    171     *
    172     * @return A clone.
    173     *
    174     * @throws CloneNotSupportedException if the <code>ArrowNeedle</code>
    175     *     cannot be cloned (in theory, this should not happen).
    176     */
    177    public Object clone() throws CloneNotSupportedException {
    178        return super.clone();
    179    }
    180
    181}