001/* ========================================================================
002 * JCommon : a free general purpose class 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/jcommon/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 * AttributedStringUtilities.java
029 * ------------------------------
030 * (C)opyright 2005, by Object Refinery Limited and Contributors.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * $Id: AttributedStringUtilities.java,v 1.2 2005/10/18 13:24:19 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 29-Jul-2005 : Version 1(DG);
040 * 
041 */
042
043package org.jfree.util;
044
045import java.text.AttributedCharacterIterator;
046import java.text.AttributedString;
047import java.text.CharacterIterator;
048import java.util.Map;
049
050/**
051 * Some utility methods for working with <code>AttributedString</code> objects.
052 * 
053 * @author David Gilbert
054 */
055public class AttributedStringUtilities {
056
057    /**
058     * Private constructor prevents object creation.
059     */
060    private AttributedStringUtilities() {
061    }
062
063    /**
064     * Tests two attributed strings for equality.
065     * 
066     * @param s1  string 1 (<code>null</code> permitted).
067     * @param s2  string 2 (<code>null</code> permitted).
068     * 
069     * @return <code>true</code> if <code>s1</code> and <code>s2</code> are
070     *         equal or both <code>null</code>, and <code>false</code> 
071     *         otherwise.
072     */
073    public static boolean equal(AttributedString s1, AttributedString s2) {
074        if (s1 == null) {
075            return (s2 == null);
076        }
077        if (s2 == null) {
078            return false;
079        }
080        AttributedCharacterIterator it1 = s1.getIterator();
081        AttributedCharacterIterator it2 = s2.getIterator();
082        char c1 = it1.first();
083        char c2 = it2.first();
084        int start = 0;
085        while (c1 != CharacterIterator.DONE) {
086            int limit1 = it1.getRunLimit();
087            int limit2 = it2.getRunLimit();
088            if (limit1 != limit2) {
089                return false;
090            }
091            // if maps aren't equivalent, return false
092            Map m1 = it1.getAttributes();
093            Map m2 = it2.getAttributes();
094            if (!m1.equals(m2)) {
095                return false;
096            }
097            // now check characters in the run are the same
098            for (int i = start; i < limit1; i++) {
099                if (c1 != c2) {
100                    return false;
101                }
102                c1 = it1.next();
103                c2 = it2.next();
104            }
105            start = limit1;
106        }
107        return c2 == CharacterIterator.DONE;
108    }
109    
110}