1   /**
2    * Distribution License:
3    * JSword is free software; you can redistribute it and/or modify it under
4    * the terms of the GNU Lesser General Public License, version 2.1 as published by
5    * the Free Software Foundation. This program is distributed in the hope
6    * that it will be useful, but WITHOUT ANY WARRANTY; without even the
7    * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
8    * See the GNU Lesser General Public License for more details.
9    *
10   * The License is available on the internet at:
11   *       http://www.gnu.org/copyleft/lgpl.html
12   * or by writing to:
13   *      Free Software Foundation, Inc.
14   *      59 Temple Place - Suite 330
15   *      Boston, MA 02111-1307, USA
16   *
17   * Copyright: 2007
18   *     The copyright to this program is held by it's authors.
19   *
20   * ID: $Id: Languages.java 1462 2007-07-02 02:32:23Z dmsmith $
21   */
22  package org.crosswire.common.util;
23  
24  /**
25   * A single language, paring an ISO-639 code to a localized representation of
26   * the language.
27   * 
28   * @see gnu.lgpl.License for license details.<br>
29   *      The copyright to this program is held by it's authors.
30   * @author DM Smith [dmsmith555 at yahoo dot com]
31   */
32  public class Language implements Comparable<Language> {
33      public static final Language DEFAULT_LANG = new Language(null);
34  
35      /**
36       * A single language defined by an ISO-639 code. If the code is null or
37       * empty then it is considered to be DEFAULT_LANG_CODE (that is, English).
38       * 
39       * @param iso639Code
40       *            the particular language
41       */
42      public Language(String iso639Code) {
43          this.code = Languages.getLanguageCode(iso639Code);
44      }
45  
46      /**
47       * Determine whether this language is valid. The code is valid if it is in
48       * iso639.properties.
49       * 
50       * @return true if the language is valid.
51       */
52      public boolean isValidLanguage() {
53          return Languages.isValidLanguage(code);
54      }
55  
56      /**
57       * Get the language code.
58       * 
59       * @return the code for the language
60       */
61      public String getCode() {
62          return code;
63      }
64  
65      /**
66       * Get the language name.
67       * 
68       * @return the name of the language
69       */
70      public String getName() {
71          if (name == null) {
72              name = Languages.getLanguageName(code);
73          }
74          return name;
75      }
76  
77      /**
78       * Determine whether this language is a Left-to-Right or a Right-to-Left
79       * language. Note: This is problematic. Languages do not have direction.
80       * Scripts do. Further, there are over 7000 living languages, many of which
81       * are written in Right-to-Left scripts and are not listed here.
82       * 
83       * @return true if the language is Left-to-Right.
84       */
85      public boolean isLeftToRight() {
86          if (!knowsDirection) {
87              // TODO(DMS): Improve this.
88              ltor = !("he".equals(code)  || // Hebrew
89                       "ar".equals(code)  || // Arabic
90                       "fa".equals(code)  || // Farsi/Persian
91                       "ur".equals(code)  || // Uighur
92                       "uig".equals(code) || // Uighur, too
93                       "syr".equals(code) || // Syriac
94                       "iw".equals(code));   // Java's notion of Hebrew
95  
96              knowsDirection = true;
97          }
98  
99          return ltor;
100     }
101 
102     /*
103      * (non-Javadoc)
104      * 
105      * @see java.lang.Object#hashCode()
106      */
107     @Override
108     public int hashCode() {
109         return code.hashCode();
110     }
111 
112     /*
113      * (non-Javadoc)
114      * 
115      * @see java.lang.Object#equals(java.lang.Object)
116      */
117     @Override
118     public boolean equals(Object obj) {
119         if (this == obj) {
120             return true;
121         }
122 
123         if (obj == null || getClass() != obj.getClass()) {
124             return false;
125         }
126 
127         final Language other = (Language) obj;
128 
129         return code.equals(other.code);
130     }
131 
132     /*
133      * (non-Javadoc)
134      * 
135      * @see java.lang.Object#toString()
136      */
137     @Override
138     public String toString() {
139         return getName();
140     }
141 
142     /*
143      * (non-Javadoc)
144      * 
145      * @see java.lang.Comparable#compareTo(java.lang.Object)
146      */
147     public int compareTo(Language o) {
148         return getName().compareTo(o.toString());
149     }
150 
151     private String code;
152     private String name;
153     private boolean knowsDirection;
154     private boolean ltor;
155 }
156