Initial move from old twain-in-dotnet.

NTwain/Triplets/DGControl/DGControl.XferGroup.cs

@@ -0,0 +1,60 @@
+// The MIT License (MIT)
+// Copyright (c) 2013 Yin-Chun Wang
+//
+// Permission is hereby granted, free of charge, to any person obtaining a 
+// copy of this software and associated documentation files (the "Software"), 
+// to deal in the Software without restriction, including without limitation 
+// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+// and/or sell copies of the Software, and to permit persons to whom the 
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included 
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF 
+// OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+using System;
+using NTwain.Data;
+using NTwain.Values;
+
+namespace NTwain.Triplets
+{
+	public sealed class XferGroup : OpBase
+	{
+		internal XferGroup(TwainSession session) : base(session) { }
+		/// <summary>
+		/// Returns the Data Group (the type of data) for the upcoming transfer. The Source is required to
+		/// only supply one of the DGs specified in the SupportedGroups field of origin.
+		/// </summary>
+		/// <param name="value">The value.</param>
+		/// <returns></returns>
+		public ReturnCode Get(out uint value)
+		{
+			Session.VerifyState(4, 6, DataGroups.Control, DataArgumentType.XferGroup, Message.Get);
+			throw new NotImplementedException();
+
+			// TODO: I have no idea if this even works, just something that looks logical.
+			// Does memory from pointer need to be released once we got the value?
+
+			//IntPtr ptr = IntPtr.Zero;
+			//var rc = Custom.DsmEntry(Session.AppId, Session.SourceId, DataGroup.Control, DataArgumentType.XferGroup, Message.Get, ref ptr);
+			//unsafe
+			//{
+			//    uint* realPtr = (uint*)ptr.ToPointer();
+			//    value = (*realPtr);
+			//}
+			//return rc;
+		}
+
+		public ReturnCode Set(uint value)
+		{
+			Session.VerifyState(6, 6, DataGroups.Control, DataArgumentType.XferGroup, Message.Set);
+			throw new NotImplementedException();
+		}
+	}
+}