Added support for LightPath

src/TestVb/MainForm.vb

@@ -69,6 +69,7 @@ Public Class MainForm
         settings.ShowTwainUI = useUICheckBox.Checked
         settings.ShowProgressIndicatorUI = showProgressIndicatorUICheckBox.Checked
         settings.UseDuplex = useDuplexCheckBox.Checked
+        settings.UseFilmScanner = False
         settings.Resolution = If(blackAndWhiteCheckBox.Checked, ResolutionSettings.Fax, ResolutionSettings.ColourPhotocopier)
         settings.Area = If(Not checkBoxArea.Checked, Nothing, areaSettings)
         settings.ShouldTransferAllPages = True

src/TwainDotNet/DataSource.cs

@@ -146,6 +146,23 @@ public bool SupportsDuplex
             }
         }
 
+        public bool SupportsFilmScanner
+        {
+            get
+            {
+                try
+                {
+                    var cap = new Capability(Capabilities.Lightpath, TwainType.Int16, _applicationId, SourceId);
+//                    return ((Lightpath)cap.GetBasicValue().Int16Value) != Lightpath.Transmissive;
+                    return true;
+                }
+                catch
+                {
+                    return false;
+                }
+            }
+        }
+
         public void NegotiateColour(ScanSettings scanSettings)
         {
             try
@@ -203,6 +220,27 @@ public void NegotiateDuplex(ScanSettings scanSettings)
                 // Do nothing if the data source does not support the requested capability
             }
         }
+        public void NegotiateLightPath(ScanSettings scanSettings)
+        {
+            try
+            {
+                if (scanSettings.UseFilmScanner.HasValue && SupportsFilmScanner)
+                {
+                    if (scanSettings.UseFilmScanner.Value == true)
+                    {
+                        Capability.SetBasicCapability(Capabilities.Lightpath, (ushort)Lightpath.Transmissive, TwainType.UInt16, _applicationId, SourceId);
+                    }
+                    else
+                    {
+                        Capability.SetBasicCapability(Capabilities.Lightpath, (ushort)Lightpath.Reflective, TwainType.UInt16, _applicationId, SourceId);
+                    }
+                }
+            }
+            catch
+            {
+                // Do nothing if the data source does not support the requested capability
+            }
+        }
 
         public void NegotiateOrientation(ScanSettings scanSettings)
         {
@@ -310,6 +348,7 @@ public bool Open(ScanSettings settings)
             NegotiateTransferCount(settings);
             NegotiateFeeder(settings);
             NegotiateDuplex(settings);
+            NegotiateLightPath(settings);
 
             if (settings.UseDocumentFeeder == true &&
                 settings.Page != null)
@@ -561,16 +600,13 @@ public void Close()
                     Message.DisableDS,
                     userInterface);
 
-                if (result != TwainResult.Failure)
-                {
-                    result = Twain32Native.DsmIdentity(
-                        _applicationId,
-                        IntPtr.Zero,
-                        DataGroup.Control,
-                        DataArgumentType.Identity,
-                        Message.CloseDS,
-                        SourceId);
-                }
+                result = Twain32Native.DsmIdentity(
+                    _applicationId,
+                    IntPtr.Zero,
+                    DataGroup.Control,
+                    DataArgumentType.Identity,
+                    Message.CloseDS,
+                    SourceId);
             }
         }
     }

src/TwainDotNet/ScanSettings.cs

@@ -70,6 +70,24 @@ public bool? UseDocumentFeeder
             }
         }
 
+        bool? _useFilmScanner;
+
+        /// <summary>
+        /// Indicates if the transmitted light film SCanner should be used as the light source.
+        /// </summary>
+        public bool? UseFilmScanner
+        {
+            get { return _useFilmScanner; }
+            set
+            {
+                if (value != _useFilmScanner)
+                {
+                    _useFilmScanner = value;
+                    OnPropertyChanged("UseFilmScanner");
+                }
+            }
+        }
+
         bool? _useAutoFeeder;
 
         /// <summary>

src/TwainDotNet/TwainDotNet.csproj

@@ -70,6 +70,7 @@
     <Compile Include="TwainNative\CapabilityArrayValue.cs" />
     <Compile Include="TwainNative\CapabilityEnumValue.cs" />
     <Compile Include="TwainNative\CapabilityOneValue.cs" />
+    <Compile Include="TwainNative\Lightpath.cs" />
     <Compile Include="TwainNative\Command.cs" />
     <Compile Include="TwainNative\Compression.cs" />
     <Compile Include="TwainNative\ConditionCode.cs" />

src/TwainDotNet/TwainNative/Lightpath.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace TwainDotNet.TwainNative
+{
+        /// <summary>
+        /// Twain spec ICAP_Lightpath values.
+        /// </summary>
+        public enum Lightpath : short
+        {
+            Reflective = 0,
+            Transmissive = 1
+        }
+}