mcs/class/referencesource/System.Activities.Presentation/Microsoft.Tools.Common/Microsoft/Activities/Presentation/Xaml/ViewStateIdManager.cs

   1 // <copyright>
   2 //   Copyright (c) Microsoft Corporation.  All rights reserved.
   3 // </copyright>
   4
   5 namespace Microsoft.Activities.Presentation.Xaml
   6 {
   7     using System.Collections.Generic;
   8
   9     class ViewStateIdManager
  10     {
  11         readonly char separatorChar = '_';
  12         Dictionary<string, int> prefixToIntMap = new Dictionary<string, int>();
  13
  14         public void UpdateMap(string id)
  15         {
  16             int separatorLocation = id.LastIndexOf('_');
  17
  18             // If the separator is not found or if the separator is the first or last character
  19             // in the id then use id value itself as the prefix.
  20             if (separatorLocation == -1 || separatorLocation == 0 || separatorLocation == id.Length - 1)
  21             {
  22                 this.prefixToIntMap[id] = 0;
  23             }
  24             else
  25             {
  26                 string[] idParts = new string[2];
  27                 idParts[0] = id.Substring(0, separatorLocation);
  28                 idParts[1] = id.Substring(separatorLocation + 1, id.Length - (separatorLocation + 1));
  29
  30                 int suffix;
  31                 if (int.TryParse(idParts[1], out suffix))
  32                 {
  33                     int oldValue;
  34                     if (this.prefixToIntMap.TryGetValue(idParts[0], out oldValue))
  35                     {
  36                         if (suffix > oldValue)
  37                         {
  38                             this.prefixToIntMap[idParts[0]] = suffix;
  39                         }
  40                     }
  41                     else
  42                     {
  43                         this.prefixToIntMap[idParts[0]] = suffix;
  44                     }
  45                 }
  46                 else
  47                 {
  48                     this.prefixToIntMap[id] = 0;
  49                 }
  50             }
  51         }
  52
  53         public string GetNewId(string prefix)
  54         {
  55             int suffix = 0;
  56             this.prefixToIntMap.TryGetValue(prefix, out suffix);
  57
  58             while (suffix == int.MaxValue)
  59             {
  60                 prefix = prefix + this.separatorChar + suffix;
  61                 this.prefixToIntMap.TryGetValue(prefix, out suffix);
  62             }
  63
  64             this.prefixToIntMap[prefix] = ++suffix;
  65             return prefix + this.separatorChar + suffix;
  66         }
  67     };
  68 }