mcs/class/System.ComponentModel.Composition/src/ComponentModel/System/ComponentModel/Composition/Hosting/CatalogExportProvider.CatalogChangeProxy.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Collections.Generic;\r
   6 using System.ComponentModel.Composition.Primitives;\r
   7 using System.Diagnostics;\r
   8 using System.Diagnostics.CodeAnalysis;\r
   9 using System.Globalization;\r
  10 using System.Linq;\r
  11 using System.Runtime.CompilerServices;\r
  12 using System.Threading;\r
  13 using Microsoft.Internal;\r
  14 using Microsoft.Internal.Collections;\r
  15 \r
  16 namespace System.ComponentModel.Composition.Hosting\r
  17 {\r
  18     public partial class CatalogExportProvider : ExportProvider, IDisposable\r
  19     {\r
  20         private class CatalogChangeProxy : ComposablePartCatalog\r
  21         {\r
  22             private ComposablePartCatalog _originalCatalog;\r
  23             private List<ComposablePartDefinition> _addedParts;\r
  24             private HashSet<ComposablePartDefinition> _removedParts;\r
  25 \r
  26             public CatalogChangeProxy(ComposablePartCatalog originalCatalog,\r
  27                 IEnumerable<ComposablePartDefinition> addedParts,\r
  28                 IEnumerable<ComposablePartDefinition> removedParts)\r
  29             {\r
  30                 this._originalCatalog = originalCatalog;\r
  31                 this._addedParts = new List<ComposablePartDefinition>(addedParts);\r
  32                 this._removedParts = new HashSet<ComposablePartDefinition>(removedParts);\r
  33             }\r
  34 \r
  35             public override IQueryable<ComposablePartDefinition> Parts\r
  36             {\r
  37                 get\r
  38                 {\r
  39                     return this._originalCatalog.Parts.Concat(this._addedParts).Except(this._removedParts);\r
  40                 }\r
  41             }\r
  42 \r
  43             public override IEnumerable<Tuple<ComposablePartDefinition, ExportDefinition>> GetExports(\r
  44                 ImportDefinition definition)\r
  45             {\r
  46                 Requires.NotNull(definition, "definition");\r
  47 \r
  48                 var originalExports = this._originalCatalog.GetExports(definition);\r
  49                 var trimmedExports = originalExports.Where(partAndExport =>\r
  50                     !this._removedParts.Contains(partAndExport.Item1));\r
  51 \r
  52                 var addedExports = new List<Tuple<ComposablePartDefinition, ExportDefinition>>();\r
  53                 foreach (var part in this._addedParts)\r
  54                 {\r
  55                     foreach (var export in part.ExportDefinitions)\r
  56                     {\r
  57                         if (definition.IsConstraintSatisfiedBy(export))\r
  58                         {\r
  59                             addedExports.Add(new Tuple<ComposablePartDefinition, ExportDefinition>(part, export));\r
  60                         }\r
  61                     }\r
  62                 }\r
  63                 return trimmedExports.Concat(addedExports);\r
  64             }\r
  65         }\r
  66     }\r
  67 }\r