001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, 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     * NumberTickUnit.java
029     * -------------------
030     * (C) Copyright 2001-2005, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: NumberTickUnit.java,v 1.3.2.3 2005/10/25 20:37:34 mungady Exp $
036     *
037     * Changes (from 19-Dec-2001)
038     * --------------------------
039     * 19-Dec-2001 : Added standard header (DG);
040     * 01-May-2002 : Updated for changed to TickUnit class (DG);
041     * 01-Oct-2002 : Fixed errors reported by Checkstyle (DG);
042     * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
043     * 09-Jan-2002 : Added a new constructor (DG);
044     * 26-Mar-2003 : Implemented Serializable (DG);
045     * 05-Jul-2005 : Added equals() implementation (DG);
046     * 05-Sep-2005 : Implemented hashCode(), thanks to Thomas Morgner (DG);
047     *
048     */
049    
050    package org.jfree.chart.axis;
051    
052    import java.io.Serializable;
053    import java.text.NumberFormat;
054    
055    /**
056     * A numerical tick unit.
057     */
058    public class NumberTickUnit extends TickUnit implements Serializable {
059    
060        /** For serialization. */
061        private static final long serialVersionUID = 3849459506627654442L;
062        
063        /** A formatter for the tick unit. */
064        private NumberFormat formatter;
065    
066        /**
067         * Creates a new number tick unit.
068         *
069         * @param size  the size of the tick unit.
070         */
071        public NumberTickUnit(double size) {
072            this(size, NumberFormat.getNumberInstance());
073        }
074    
075        /**
076         * Creates a new number tick unit.
077         *
078         * @param size  the size of the tick unit.
079         * @param formatter  a number formatter for the tick unit (<code>null</code>
080         *                   not permitted).
081         */
082        public NumberTickUnit(double size, NumberFormat formatter) {
083            super(size);
084            if (formatter == null) {
085                throw new IllegalArgumentException("Null 'formatter' argument.");
086            }
087            this.formatter = formatter;
088        }
089    
090        /**
091         * Converts a value to a string.
092         *
093         * @param value  the value.
094         *
095         * @return The formatted string.
096         */
097        public String valueToString(double value) {
098            return this.formatter.format(value);
099        }
100        
101        /**
102         * Tests this formatter for equality with an arbitrary object.
103         * 
104         * @param obj  the object (<code>null</code> permitted).
105         * 
106         * @return A boolean.
107         */
108        public boolean equals(Object obj) {
109            if (obj == this) {
110                return true;
111            }
112            if (!(obj instanceof NumberTickUnit)) {
113                return false;
114            }
115            if (!super.equals(obj)) {
116                return false;
117            }
118            NumberTickUnit that = (NumberTickUnit) obj;
119            if (!this.formatter.equals(that.formatter)) {
120                return false;
121            }
122            return true;
123        }
124    
125        /**
126         * Returns a hash code for this instance.
127         * 
128         * @return A hash code.
129         */
130        public int hashCode() {
131            int result = super.hashCode();
132            result = 29 * result + (formatter != null ? formatter.hashCode() : 0);
133            return result;
134        }
135    
136    }