mcs/class/corlib/System/__ComObject.cs

   1 //
   2 // System.__ComObject
   3 //
   4 // Authors:
   5 //   Sebastien Pouliot <sebastien@ximian.com>
   6 //   Kornél Pál <http://www.kornelpal.hu/>
   7 //   Jonathan Chambers <joncham@gmail.com>
   8 //
   9 // Copyright (C) 2004 Novell (http://www.novell.com)
  10 // Copyright (C) 2005 Kornél Pál
  11 // Copyright (C) 2006 Jonathan Chambers
  12 //
  13
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using Mono.Interop;
  36 using System.Collections;
  37 using System.Runtime.InteropServices;
  38 using System.Runtime.CompilerServices;
  39
  40 namespace System
  41 {
  42         // This is a private class that is used as a generic wrapper class
  43         // for COM objects that have no specific wrapper class.
  44         //
  45         // It has no public methods, it's functionality is exposed trough
  46         // System.Runtime.InteropServices.Marshal class and can be casted to
  47         // any interface that is implemented by the wrapped COM object.
  48         //
  49         // This class is referenced in .NET Framework SDK Documentation so
  50         // many times that obj.GetType().FullName == "System.__ComObject" and
  51         // Type.GetType("System.__ComObject") may be used.
  52
  53         internal class __ComObject : MarshalByRefObject
  54         {
  55                 #region Sync with object-internals.h
  56                 IntPtr hash_table;
  57                 #endregion
  58
  59                 // this is used internally and for the the methods
  60                 // Marshal.GetComObjectData and Marshal.SetComObjectData
  61                 Hashtable hashtable;
  62
  63                 [ThreadStatic]
  64                 static bool coinitialized;
  65
  66                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
  67                 internal extern void Finalizer ();
  68
  69                 ~__ComObject ()
  70                 {
  71                         ComInteropProxy.ReleaseComObject (this);
  72                         Finalizer ();
  73                 }
  74
  75                 public __ComObject ()
  76                 {
  77                         // call CoInitialize once per thread
  78                         if (!coinitialized) {
  79                                 CoInitialize (IntPtr.Zero);
  80                                 coinitialized = true;
  81                         }
  82
  83                         hashtable = new Hashtable ();
  84
  85                         IntPtr ppv;
  86                         Type t = GetType ();
  87                         int hr = CoCreateInstance (GetCLSID (t), IntPtr.Zero, 0x1 | 0x4 | 0x10, IID_IUnknown, out ppv);
  88                         Marshal.ThrowExceptionForHR (hr);
  89
  90                         SetIUnknown (ppv);
  91                 }
  92
  93                 internal __ComObject (Type t)
  94                 {
  95                         // call CoInitialize once per thread
  96                         if (!coinitialized) {
  97                                 CoInitialize (IntPtr.Zero);
  98                                 coinitialized = true;
  99                         }
 100
 101                         hashtable = new Hashtable ();
 102
 103                         IntPtr ppv;
 104                         int hr = CoCreateInstance (GetCLSID (t), IntPtr.Zero, 0x1 | 0x4 | 0x10, IID_IUnknown, out ppv);
 105                         Marshal.ThrowExceptionForHR (hr);
 106
 107                         SetIUnknown (ppv);
 108                 }
 109
 110                 private Guid GetCLSID (Type t)
 111                 {
 112                         if (t.IsImport)
 113                                 return t.GUID;
 114
 115                         // look at supertypes
 116                         Type super = t.BaseType;
 117                         while (super != typeof (object)) {
 118                                 if (super.IsImport)
 119                                         return super.GUID;
 120                                 super = super.BaseType;
 121                         }
 122                         throw new COMException ("Could not find base COM type for type " + t.ToString());
 123                 }
 124
 125                 internal __ComObject (IntPtr pItf)
 126                 {
 127                         hashtable = new Hashtable ();
 128                         IntPtr ppv;
 129                         Guid iid = IID_IUnknown;
 130                         int hr = Marshal.QueryInterface (pItf, ref iid, out ppv);
 131                         Marshal.ThrowExceptionForHR (hr);
 132                         SetIUnknown (ppv);
 133         }
 134
 135                 public Hashtable Hashtable
 136                 {
 137                         get
 138                         {
 139                                 return hashtable;
 140                         }
 141                 }
 142
 143                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 144                 internal static extern __ComObject CreateRCW (Type t);
 145
 146                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 147                 extern void SetIUnknown (IntPtr t);
 148
 149                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 150                 extern IntPtr GetIUnknown ();
 151
 152                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 153                 extern IntPtr FindInterface (Type t);
 154
 155                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 156                 extern void CacheInterface (Type t, IntPtr pItf);
 157
 158                 internal IntPtr GetInterface(Type t)
 159                 {
 160                         // this is needed later and checks to see if we are
 161                         // a valid RCW
 162                         IntPtr pUnk = IUnknown;
 163                         IntPtr pItf = FindInterface (t);
 164                         if (pItf != IntPtr.Zero) {
 165                                 return pItf;
 166                         }
 167
 168                         Guid iid = t.GUID;
 169                         IntPtr ppv;
 170                         int hr = Marshal.QueryInterface (pUnk, ref iid, out ppv);
 171                         Marshal.ThrowExceptionForHR (hr);
 172                         CacheInterface (t, ppv);
 173                         return ppv;
 174                 }
 175
 176                 internal IntPtr IUnknown
 177                 {
 178                         get
 179                         {
 180                                 IntPtr pUnk = GetIUnknown();
 181                                 if (pUnk == IntPtr.Zero)
 182                                         throw new InvalidComObjectException ("COM object that has been separated from its underlying RCW cannot be used.");
 183                                 return pUnk;
 184                         }
 185                 }
 186
 187                 internal IntPtr IDispatch
 188                 {
 189                         get
 190                         {
 191                                 IntPtr pUnk = GetInterface (typeof (IDispatch));
 192                                 if (pUnk == IntPtr.Zero)
 193                                         throw new InvalidComObjectException ("COM object that has been separated from its underlying RCW cannot be used.");
 194                                 return pUnk;
 195                         }
 196                 }
 197
 198                 internal static Guid IID_IUnknown
 199                 {
 200                         get
 201                         {
 202                                 return new Guid("00000000-0000-0000-C000-000000000046");
 203                         }
 204                 }
 205
 206                 internal static Guid IID_IDispatch
 207                 {
 208                         get
 209                         {
 210                                 return new Guid ("00020400-0000-0000-C000-000000000046");
 211                         }
 212                 }
 213
 214                 public override bool Equals (object obj)
 215                 {
 216                         if (obj == null)
 217                                 return false;
 218
 219                         __ComObject co = obj as __ComObject;
 220                         if ((object)co == null)
 221                                 return false;
 222
 223                         return (IUnknown == co.IUnknown);
 224                 }
 225
 226                 public override int GetHashCode ()
 227                 {
 228                         // not what MS seems to do,
 229                         // but IUnknown is identity in COM
 230                         return IUnknown.ToInt32 ();
 231                 }
 232
 233                 [DllImport ("ole32.dll", CallingConvention = CallingConvention.StdCall)]
 234                 static extern int CoInitialize (IntPtr pvReserved);
 235
 236                 [DllImport ("ole32.dll", CallingConvention = CallingConvention.StdCall, ExactSpelling = true, PreserveSig = true)]
 237                 static extern int CoCreateInstance (
 238                    [In, MarshalAs (UnmanagedType.LPStruct)] Guid rclsid,
 239                    IntPtr pUnkOuter,
 240                    uint dwClsContext,
 241                   [In, MarshalAs (UnmanagedType.LPStruct)] Guid riid,
 242                         out IntPtr pUnk);
 243         }
 244 }