mcs/class/System.ComponentModel.Composition/Tests/ComponentModelUnitTest/System/ComponentModel/Composition/Factories/ExportProviderFactory.RecomposableExportProvider.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Linq;\r
   6 using System.ComponentModel.Composition;\r
   7 using System.ComponentModel.Composition.Hosting;\r
   8 using System.ComponentModel.Composition.Primitives;\r
   9 using System.Collections.Generic;\r
  10 using System.Linq.Expressions;\r
  11 using Microsoft.VisualStudio.TestTools.UnitTesting;\r
  12 \r
  13 namespace System.ComponentModel.Composition.Factories\r
  14 {\r
  15     partial class ExportProviderFactory\r
  16     {\r
  17         public class RecomposableExportProvider : ExportProvider\r
  18         {\r
  19             public static Dictionary<string, object> EmptyMetadataDictionary = new Dictionary<string, object>();\r
  20             public List<Export> _exports = new List<Export>();\r
  21 \r
  22             public void AddExport(string contractName, object value)\r
  23             {\r
  24                 Export export = CreateExport(contractName, value);\r
  25                 var exports = this._exports.ToList();\r
  26 \r
  27                 exports.Add(export);\r
  28                 ChangeExports(exports);\r
  29             }\r
  30 \r
  31             public void RemoveExport(string contractName)\r
  32             {\r
  33                 int index = FindExport(contractName);\r
  34                 Assert.IsTrue(index >= 0);\r
  35 \r
  36                 var exports = this._exports.ToList();\r
  37 \r
  38                 exports.RemoveAt(index);\r
  39 \r
  40                 ChangeExports(exports);\r
  41             }\r
  42 \r
  43             public void ReplaceExportValue(string contractName, object newValue)\r
  44             {\r
  45                 int index = FindExport(contractName);\r
  46                 Assert.IsTrue(index >= 0);\r
  47 \r
  48                 var exports = this._exports.ToList();\r
  49 \r
  50                 exports.RemoveAt(index);\r
  51                 exports.Add(CreateExport(contractName, newValue));\r
  52 \r
  53                 ChangeExports(exports);\r
  54             }\r
  55 \r
  56             private void ChangeExports(List<Export> newExports)\r
  57             {\r
  58                 using (var atomicComposition = new AtomicComposition())\r
  59                 {\r
  60                     atomicComposition.AddCompleteAction(() => this._exports = newExports);\r
  61                     atomicComposition.SetValue(this, newExports);\r
  62 \r
  63                     var addedExports = newExports.Except(this._exports).Select(export => export.Definition);\r
  64                     var removedExports = this._exports.Except(newExports).Select(export => export.Definition);\r
  65 \r
  66                     this.OnExportsChanging(new ExportsChangeEventArgs(addedExports, removedExports, atomicComposition));\r
  67 \r
  68                     atomicComposition.AddCompleteAction(() => this.OnExportsChanged(\r
  69                         new ExportsChangeEventArgs(addedExports, removedExports, null)));\r
  70 \r
  71                     atomicComposition.Complete();\r
  72                 }\r
  73             }\r
  74 \r
  75             private int FindExport(string contractName)\r
  76             {\r
  77                 for (int i = 0; i < _exports.Count; i++)\r
  78                 {\r
  79                     if (_exports[i].Definition.ContractName == contractName)\r
  80                     {\r
  81                         return i;\r
  82                     }\r
  83                 }\r
  84                 return -1;\r
  85             }\r
  86 \r
  87             private Export CreateExport(string contractName, object value)\r
  88             {\r
  89                 return new Export(new ExportDefinition(contractName, EmptyMetadataDictionary), () => value);\r
  90             }\r
  91 \r
  92             protected override IEnumerable<Export> GetExportsCore(ImportDefinition importDefinition, AtomicComposition context)\r
  93             {\r
  94                 IEnumerable<Export> contextExports;\r
  95 \r
  96                 if (context == null || !context.TryGetValue(this, out contextExports))\r
  97                 {\r
  98                     contextExports = this._exports;\r
  99                 }\r
 100 \r
 101                 List<Export> exports = new List<Export>();\r
 102                 var func = importDefinition.Constraint.Compile();\r
 103                 foreach (Export export in contextExports)\r
 104                 {\r
 105                     if (func(export.Definition))\r
 106                     {\r
 107                         exports.Add(export);\r
 108                     }\r
 109                 }\r
 110                 return exports;\r
 111             }\r
 112         }\r
 113     }\r
 114 }\r