001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2007, 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 2002-2007, 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 */
043
044package org.jfree.chart.needle;
045
046import java.awt.Graphics2D;
047import java.awt.Shape;
048import java.awt.geom.GeneralPath;
049import java.awt.geom.Line2D;
050import java.awt.geom.Point2D;
051import java.awt.geom.Rectangle2D;
052import java.io.Serializable;
053
054/**
055 * A needle in the shape of an arrow.
056 */
057public class ArrowNeedle extends MeterNeedle 
058                         implements Cloneable, Serializable {
059
060    /** For serialization. */
061    private static final long serialVersionUID = -5334056511213782357L;
062    
063    /** 
064     * A flag controlling whether or not there is an arrow at the top of the 
065     * needle. 
066     */
067    private boolean isArrowAtTop = true;
068
069    /**
070     * Constructs a new arrow needle.
071     *
072     * @param isArrowAtTop  a flag that controls whether or not there is an 
073     *                      arrow at the top of the needle.
074     */
075    public ArrowNeedle(boolean isArrowAtTop) {
076        this.isArrowAtTop = isArrowAtTop;
077    }
078
079    /**
080     * Draws the needle.
081     *
082     * @param g2  the graphics device.
083     * @param plotArea  the plot area.
084     * @param rotate  the rotation point.
085     * @param angle  the angle.
086     */
087    protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
088                              Point2D rotate, double angle) {
089
090        Line2D shape = new Line2D.Float();
091        Shape d = null;
092
093        float x = (float) (plotArea.getMinX() +  (plotArea.getWidth() / 2));
094        float minY = (float) plotArea.getMinY();
095        float maxY = (float) plotArea.getMaxY();
096        shape.setLine(x, minY, x, maxY);
097
098        GeneralPath shape1 = new GeneralPath();
099        if (this.isArrowAtTop) {
100            shape1.moveTo(x, minY);
101            minY += 4 * getSize();
102        }
103        else {
104            shape1.moveTo(x, maxY);
105            minY = maxY - 4 * getSize();
106        }
107        shape1.lineTo(x + getSize(), minY);
108        shape1.lineTo(x - getSize(), minY);
109        shape1.closePath();
110
111        if ((rotate != null) && (angle != 0)) {
112            getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
113            d = getTransform().createTransformedShape(shape);
114        }
115        else {
116            d = shape;
117        }
118        defaultDisplay(g2, d);
119
120        if ((rotate != null) && (angle != 0)) {
121            d = getTransform().createTransformedShape(shape1);
122        }
123        else {
124            d = shape1;
125        }
126        defaultDisplay(g2, d);
127
128    }
129
130    /**
131     * Tests another object for equality with this object.
132     * 
133     * @param obj  the object to test (<code>null</code> permitted).
134     * 
135     * @return A boolean.
136     */
137    public boolean equals(Object obj) {
138        if (obj == this) {
139            return true;
140        }
141        if (!(obj instanceof ArrowNeedle)) {
142            return false; 
143        }
144        if (!super.equals(obj)) {
145            return false;
146        }
147        ArrowNeedle that = (ArrowNeedle) obj;
148        if (this.isArrowAtTop != that.isArrowAtTop) {
149            return false;
150        }
151        return true;
152    }
153    
154    /**
155     * Returns a clone of this needle.
156     * 
157     * @return A clone.
158     * 
159     * @throws CloneNotSupportedException if the <code>ArrowNeedle</code> 
160     *     cannot be cloned (in theory, this should not happen).
161     */
162    public Object clone() throws CloneNotSupportedException {
163        return super.clone();   
164    }
165    
166}