001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 * 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}