mcs/class/System.ComponentModel.Composition/src/ComponentModel/Microsoft/Internal/Collections/CollectionServices.CollectionOfObject.cs

   1 // -----------------------------------------------------------------------\r
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.\r
   3 // -----------------------------------------------------------------------\r
   4 using System;\r
   5 using System.Collections;\r
   6 using System.Collections.Generic;\r
   7 using System.Reflection;\r
   8 \r
   9 namespace Microsoft.Internal.Collections\r
  10 {\r
  11     internal static partial class CollectionServices\r
  12     {\r
  13         public static ICollection<object> GetCollectionWrapper(Type itemType, object collectionObject)\r
  14         {\r
  15             Assumes.NotNull(itemType, collectionObject);\r
  16 \r
  17             if (itemType == typeof(object))\r
  18             {\r
  19                 return (ICollection<object>)collectionObject;\r
  20             }\r
  21 \r
  22             // Most common .Net collections implement IList as well so for those\r
  23             // cases we can optimize the wrapping instead of using reflection to create\r
  24             // a generic type.\r
  25             if (typeof(IList).IsAssignableFrom(collectionObject.GetType()))\r
  26             {\r
  27                 return new CollectionOfObjectList((IList)collectionObject);\r
  28             }\r
  29 \r
  30             Type collectionType = typeof(CollectionOfObject<>).MakeGenericType(itemType);\r
  31 \r
  32             return (ICollection<object>)Activator.CreateInstance(collectionType, collectionObject);           \r
  33         }\r
  34 \r
  35         private class CollectionOfObjectList : ICollection<object>\r
  36         {\r
  37             private readonly IList _list;\r
  38 \r
  39             public CollectionOfObjectList(IList list)\r
  40             {\r
  41                 this._list = list;\r
  42             }\r
  43 \r
  44             public void Add(object item)\r
  45             {\r
  46                 this._list.Add(item);\r
  47             }\r
  48 \r
  49             public void Clear()\r
  50             {\r
  51                 this._list.Clear();\r
  52             }\r
  53 \r
  54             public bool Contains(object item)\r
  55             {\r
  56                 return Assumes.NotReachable<bool>();\r
  57             }\r
  58 \r
  59             public void CopyTo(object[] array, int arrayIndex)\r
  60             {\r
  61                 Assumes.NotReachable<object>();\r
  62             }\r
  63 \r
  64             public int Count\r
  65             {\r
  66                 get { return Assumes.NotReachable<int>(); }\r
  67             }\r
  68 \r
  69             public bool IsReadOnly\r
  70             {\r
  71                 get { return this._list.IsReadOnly; }\r
  72             }\r
  73 \r
  74             public bool Remove(object item)\r
  75             {\r
  76                 return Assumes.NotReachable<bool>();\r
  77             }\r
  78 \r
  79             public IEnumerator<object> GetEnumerator()\r
  80             {\r
  81                 return Assumes.NotReachable<IEnumerator<object>>();\r
  82             }\r
  83 \r
  84             IEnumerator IEnumerable.GetEnumerator()\r
  85             {\r
  86                 return Assumes.NotReachable<IEnumerator>();\r
  87             }\r
  88         }\r
  89 \r
  90         private class CollectionOfObject<T> : ICollection<object>\r
  91         {\r
  92             private readonly ICollection<T> _collectionOfT;\r
  93 \r
  94             public CollectionOfObject(object collectionOfT)\r
  95             {\r
  96                 this._collectionOfT = (ICollection<T>)collectionOfT;\r
  97             }\r
  98 \r
  99             public void Add(object item)\r
 100             {\r
 101                 this._collectionOfT.Add((T) item);\r
 102             }\r
 103 \r
 104             public void Clear()\r
 105             {\r
 106                 this._collectionOfT.Clear();\r
 107             }\r
 108 \r
 109             public bool Contains(object item)\r
 110             {\r
 111                 return Assumes.NotReachable<bool>();\r
 112             }\r
 113 \r
 114             public void CopyTo(object[] array, int arrayIndex)\r
 115             {\r
 116                 Assumes.NotReachable<object>();\r
 117             }\r
 118 \r
 119             public int Count\r
 120             {\r
 121                 get { return Assumes.NotReachable<int>(); }\r
 122             }\r
 123 \r
 124             public bool IsReadOnly\r
 125             {\r
 126                 get { return this._collectionOfT.IsReadOnly; }\r
 127             }\r
 128 \r
 129             public bool Remove(object item)\r
 130             {\r
 131                 return Assumes.NotReachable<bool>();\r
 132             }\r
 133 \r
 134             public IEnumerator<object> GetEnumerator()\r
 135             {\r
 136                 return Assumes.NotReachable<IEnumerator<object>>();\r
 137             }\r
 138 \r
 139             IEnumerator IEnumerable.GetEnumerator()\r
 140             {\r
 141                 return Assumes.NotReachable<IEnumerator>();\r
 142             }\r
 143         }\r
 144     }\r
 145 }\r