mcs/class/corlib/System.Collections/CaseInsensitiveComparer.cs

   1 //
   2 // System.Collections.CaseInsensitiveComparer.cs
   3 //
   4 // Authors:
   5 //   Sergey Chaban (serge@wildwestsoftware.com)
   6 //   Eduardo Garcia Cebollero (kiwnix@yahoo.es)
   7 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   8 //
   9
  10 //
  11 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 using System.Globalization;
  34
  35 namespace System.Collections
  36 {
  37         [Serializable]
  38         [MonoTODO ("Fix serialization compatibility with MS.NET")]
  39         public class CaseInsensitiveComparer : IComparer
  40         {
  41                 private static CaseInsensitiveComparer defaultComparer = new CaseInsensitiveComparer ();
  42                 private static CaseInsensitiveComparer defaultInvariantComparer = new CaseInsensitiveComparer (true);
  43
  44                 private CultureInfo culture;
  45
  46                 // Public instance constructor
  47                 public CaseInsensitiveComparer ()
  48                 {
  49                         //LAMESPEC: This seems to be encoded while the object is created while Comparer does this at runtime.
  50                         culture = CultureInfo.CurrentCulture;
  51                 }
  52
  53                 private CaseInsensitiveComparer (bool invariant)
  54                 {
  55                         // leave culture == null
  56                 }
  57
  58                 public CaseInsensitiveComparer (CultureInfo culture)
  59                 {
  60                         if (culture == null)
  61                                 throw new ArgumentNullException ("culture");
  62
  63                         if (culture.LCID != CultureInfo.InvariantCulture.LCID)
  64                                 this.culture = culture;
  65                         // else leave culture == null
  66                 }
  67
  68                 //
  69                 // Public static properties
  70                 //
  71                 public static CaseInsensitiveComparer Default {
  72                         get {
  73                                 return defaultComparer;
  74                         }
  75                 }
  76
  77 #if NET_1_1
  78                 public
  79 #else
  80                 internal
  81 #endif
  82                 static CaseInsensitiveComparer DefaultInvariant {
  83                         get {
  84                                 return defaultInvariantComparer;
  85                         }
  86                 }
  87
  88                 //
  89                 // IComparer
  90                 //
  91                 public int Compare (object a, object b)
  92                 {
  93                         string sa = a as string;
  94                         string sb = b as string;
  95
  96                         if ((sa != null) && (sb != null)) {
  97                                 if (culture != null)
  98                                         return culture.CompareInfo.Compare (sa, sb, CompareOptions.IgnoreCase);
  99                                 else
 100                                         // FIXME: We should call directly into an invariant compare once available in string
 101                                         return CultureInfo.InvariantCulture.CompareInfo.Compare (sa, sb, CompareOptions.IgnoreCase);
 102                         }
 103                         else
 104                                 return Comparer.Default.Compare (a, b);
 105                 }
 106         }
 107 }