001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2006, 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 2002-2006, 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     * $Id: ArrowNeedle.java,v 1.3.2.3 2006/08/02 10:40:57 mungady Exp $
037     *
038     * Changes:
039     * --------
040     * 25-Sep-2002 : Version 1, contributed by Bryan Scott (DG);
041     * 27-Mar-2003 : Implemented Serializable (DG);
042     * 09-Sep-2003 : Added equals() method (DG);
043     * 08-Jun-2005 : Implemented Cloneable (DG);
044     */
045    
046    package org.jfree.chart.needle;
047    
048    import java.awt.Graphics2D;
049    import java.awt.Shape;
050    import java.awt.geom.GeneralPath;
051    import java.awt.geom.Line2D;
052    import java.awt.geom.Point2D;
053    import java.awt.geom.Rectangle2D;
054    import java.io.Serializable;
055    
056    /**
057     * A needle in the shape of an arrow.
058     */
059    public class ArrowNeedle extends MeterNeedle 
060                             implements Cloneable, Serializable {
061    
062        /** For serialization. */
063        private static final long serialVersionUID = -5334056511213782357L;
064        
065        /** 
066         * A flag controlling whether or not there is an arrow at the top of the 
067         * needle. 
068         */
069        private boolean isArrowAtTop = true;
070    
071        /**
072         * Constructs a new arrow needle.
073         *
074         * @param isArrowAtTop  a flag that controls whether or not there is an 
075         *                      arrow at the top of the needle.
076         */
077        public ArrowNeedle(boolean isArrowAtTop) {
078            this.isArrowAtTop = isArrowAtTop;
079        }
080    
081        /**
082         * Draws the needle.
083         *
084         * @param g2  the graphics device.
085         * @param plotArea  the plot area.
086         * @param rotate  the rotation point.
087         * @param angle  the angle.
088         */
089        protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, 
090                                  Point2D rotate, double angle) {
091    
092            Line2D shape = new Line2D.Float();
093            Shape d = null;
094    
095            float x = (float) (plotArea.getMinX() +  (plotArea.getWidth() / 2));
096            float minY = (float) plotArea.getMinY();
097            float maxY = (float) plotArea.getMaxY();
098            shape.setLine(x, minY, x, maxY);
099    
100            GeneralPath shape1 = new GeneralPath();
101            if (this.isArrowAtTop) {
102                shape1.moveTo(x, minY);
103                minY += 4 * getSize();
104            }
105            else {
106                shape1.moveTo(x, maxY);
107                minY = maxY - 4 * getSize();
108            }
109            shape1.lineTo(x + getSize(), minY);
110            shape1.lineTo(x - getSize(), minY);
111            shape1.closePath();
112    
113            if ((rotate != null) && (angle != 0)) {
114                getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
115                d = getTransform().createTransformedShape(shape);
116            }
117            else {
118                d = shape;
119            }
120            defaultDisplay(g2, d);
121    
122            if ((rotate != null) && (angle != 0)) {
123                d = getTransform().createTransformedShape(shape1);
124            }
125            else {
126                d = shape1;
127            }
128            defaultDisplay(g2, d);
129    
130        }
131    
132        /**
133         * Tests another object for equality with this object.
134         * 
135         * @param obj  the object to test (<code>null</code> permitted).
136         * 
137         * @return A boolean.
138         */
139        public boolean equals(Object obj) {
140            if (obj == this) {
141                return true;
142            }
143            if (!(obj instanceof ArrowNeedle)) {
144                return false; 
145            }
146            if (!super.equals(obj)) {
147                return false;
148            }
149            ArrowNeedle that = (ArrowNeedle) obj;
150            if (this.isArrowAtTop != that.isArrowAtTop) {
151                return false;
152            }
153            return true;
154        }
155        
156        /**
157         * Returns a clone of this needle.
158         * 
159         * @return A clone.
160         * 
161         * @throws CloneNotSupportedException if the <code>ArrowNeedle</code> 
162         *     cannot be cloned (in theory, this should not happen).
163         */
164        public Object clone() throws CloneNotSupportedException {
165            return super.clone();   
166        }
167        
168    }