Added cap query support example.

NTwain.Net35/NTwain.Net35.csproj

@@ -85,15 +85,15 @@
     <Compile Include="..\NTwain\Internals\MessageLoop.cs">
       <Link>Internals\MessageLoop.cs</Link>
     </Compile>
-    <Compile Include="..\NTwain\Internals\NativeMethods.cs">
-      <Link>Internals\NativeMethods.cs</Link>
-    </Compile>
     <Compile Include="..\NTwain\Internals\TentativeStateCommitable.cs">
       <Link>Internals\TentativeStateCommitable.cs</Link>
     </Compile>
     <Compile Include="..\NTwain\Internals\TransferLogic.cs">
       <Link>Internals\TransferLogic.cs</Link>
     </Compile>
+    <Compile Include="..\NTwain\Internals\UnsafeNativeMethods.cs">
+      <Link>Internals\UnsafeNativeMethods.cs</Link>
+    </Compile>
     <Compile Include="..\NTwain\Internals\WindowsHook.cs">
       <Link>Internals\WindowsHook.cs</Link>
     </Compile>

NTwain/Data/TwainValues.cs

@@ -2037,18 +2037,20 @@ namespace NTwain.Data
     /// Bit mask for querying the operation that are supported by the data source on a capability.
     /// Corresponds to TWQC_*.
     /// </summary>
-    public static class QuerySupportMask
+    [Flags]
+    public enum QuerySupport
     {
-        public const int Get = 0x1;
+        None = 0,
-        public const int Set = 0x2;
+        Get = 0x1,
-        public const int GetDefault = 0x4;
+        Set = 0x2,
-        public const int GetCurrent = 0x8;
+        GetDefault = 0x4,
-        public const int Reset = 0x10;
+        GetCurrent = 0x8,
-        public const int SetConstraint = 0x20;
+        Reset = 0x10,
-        public const int Constrainable = 0x40;
+        SetConstraint = 0x20,
-        public const int GetHelp = 0x100;
+        Constrainable = 0x40,
-        public const int GetLabel = 0x200;
+        GetHelp = 0x100,
-        public const int GetLabelEnum = 0x400;
+        GetLabel = 0x200,
+        GetLabelEnum = 0x400
     }
 
     /// <summary>

NTwain/Internals/ITwainSessionInternal.cs

@@ -3,9 +3,6 @@ using System.Collections.Generic;
 
 namespace NTwain.Internals
 {
-    /// <summary>
-    /// Internal interface for state management.
-    /// </summary>
     interface ITwainSessionInternal : ITwainSession
     {
         /// <summary>

NTwain/Internals/UnsafeNativeMethods.cs

@@ -1,26 +1,26 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Security;
 
 namespace NTwain.Internals
 {
-    static class NativeMethods
+    [SuppressUnmanagedCodeSecurity]
+    static class UnsafeNativeMethods
     {
-        // should be unsafe native methods?
-
         #region mem stuff for twain 1.x
 
         [DllImport("kernel32", SetLastError = true, EntryPoint = "GlobalAlloc")]
-        public static extern IntPtr WinGlobalAlloc(uint uFlags, UIntPtr dwBytes);
+        internal static extern IntPtr WinGlobalAlloc(uint uFlags, UIntPtr dwBytes);
 
         [DllImport("kernel32", SetLastError = true, EntryPoint = "GlobalFree")]
-        public static extern IntPtr WinGlobalFree(IntPtr hMem);
+        internal static extern IntPtr WinGlobalFree(IntPtr hMem);
 
         [DllImport("kernel32", SetLastError = true, EntryPoint = "GlobalLock")]
-        public static extern IntPtr WinGlobalLock(IntPtr handle);
+        internal static extern IntPtr WinGlobalLock(IntPtr handle);
 
         [DllImport("kernel32", SetLastError = true, EntryPoint = "GlobalUnlock")]
         [return: MarshalAs(UnmanagedType.Bool)]
-        public static extern bool WinGlobalUnlock(IntPtr handle);
+        internal static extern bool WinGlobalUnlock(IntPtr handle);
 
         #endregion
     }

NTwain/Internals/WinMemoryManager.cs

@@ -13,7 +13,7 @@ namespace NTwain
     {
         public IntPtr Allocate(uint size)
         {
-            IntPtr retVal = NativeMethods.WinGlobalAlloc(0x0040, new UIntPtr(size));
+            IntPtr retVal = UnsafeNativeMethods.WinGlobalAlloc(0x0040, new UIntPtr(size));
 
             if (retVal == IntPtr.Zero)
             {
@@ -24,17 +24,17 @@ namespace NTwain
 
         public void Free(IntPtr handle)
         {
-            NativeMethods.WinGlobalFree(handle);
+            UnsafeNativeMethods.WinGlobalFree(handle);
         }
 
         public IntPtr Lock(IntPtr handle)
         {
-            return NativeMethods.WinGlobalLock(handle);
+            return UnsafeNativeMethods.WinGlobalLock(handle);
         }
 
         public void Unlock(IntPtr handle)
         {
-            NativeMethods.WinGlobalUnlock(handle);
+            UnsafeNativeMethods.WinGlobalUnlock(handle);
         }
     }
 }

NTwain/NTwain.csproj

@@ -69,7 +69,7 @@
     <Compile Include="ITwainState.cs" />
     <Compile Include="Internals\WinMemoryManager.cs" />
     <Compile Include="Internals\MessageLoop.cs" />
-    <Compile Include="Internals\NativeMethods.cs" />
+    <Compile Include="Internals\UnsafeNativeMethods.cs" />
     <Compile Include="Platform.cs" />
     <Compile Include="Properties\Resources.Designer.cs">
       <AutoGen>True</AutoGen>

NTwain/Platform.cs

@@ -64,7 +64,7 @@ namespace NTwain
         }
 
 
-        static readonly WinMemoryManager _defaultMemManager;
+        static readonly IMemoryManager _defaultMemManager;
         static IMemoryManager _specifiedMemManager;
 
         /// <summary>

NTwain/TwainSessionExtensions.cs

@@ -6,8 +6,8 @@ using System.Linq;
 namespace NTwain
 {
     /// <summary>
-    /// Defines common methods on <see cref="TwainSession"/> using the raw
+    /// Defines useful methods on <see cref="TwainSession"/> without having to dive into
-    /// TWAIN triplet api.
+    /// the raw TWAIN triplet API.
     /// </summary>
     public static class TwainSessionExtensions
     {
@@ -68,6 +68,33 @@ namespace NTwain
 
         #region caps routines
 
+        /// <summary>
+        /// Gets the actual supported operations for a capability.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="capId">The cap identifier.</param>
+        /// <returns></returns>
+        public static QuerySupport GetCapSupport(this ITwainOperation session, CapabilityId capId)
+        {
+            if (session == null) { throw new ArgumentNullException("session"); }
+
+            QuerySupport retVal = QuerySupport.None;
+            using (TWCapability cap = new TWCapability(capId))
+            {
+                var rc = session.DGControl.Capability.QuerySupport(cap);
+                if (rc == ReturnCode.Success)
+                {
+                    var read = CapReadOut.ReadValue(cap);
+
+                    if (read.ContainerType == ContainerType.OneValue)
+                    {
+                        retVal = read.OneValue.ConvertToEnum<QuerySupport>();
+                    }
+                }
+            }
+            return retVal;
+        }
+
         /// <summary>
         /// Gets the current value for a capability.
         /// </summary>

Tests/Tester.WPF/MainWindow.xaml

@@ -25,17 +25,28 @@
                 <DataTemplate>
                     <StackPanel>
                         <TextBlock Text="{Binding Name}" TextWrapping="Wrap"></TextBlock>
-                        <TextBlock Text="{Binding Version, StringFormat='Version {0}'}" TextWrapping="Wrap" Foreground="{DynamicResource ModernForeground2}"/>
+                        <TextBlock Text="{Binding Version, StringFormat='Version {0}'}" TextWrapping="Wrap" Foreground="{DynamicResource ModernForeground2}"
-                        <TextBlock Text="{Binding Protocol, StringFormat='TWAIN {0}'}" Foreground="{DynamicResource ModernForeground2}"/>
+                                   Margin="8 0 0 0"/>
+                        <TextBlock Text="{Binding Protocol, StringFormat='TWAIN {0}'}" Foreground="{DynamicResource ModernForeground2}"
+                                   Margin="8 0 0 0"/>
                     </StackPanel>
                 </DataTemplate>
             </ListBox.ItemTemplate>
         </ListBox>
 
         <Label Content="Caps" Grid.Column="1"></Label>
-        <ListBox x:Name="CapList" Grid.Row="1" Grid.Column="1" MinWidth="100"
+        <ListBox x:Name="CapList" Grid.Row="1" Grid.Column="1" Width="150"
                  SelectionChanged="CapList_SelectionChanged"
-                 Style="{StaticResource AppListBox}"></ListBox>
+                 Style="{StaticResource AppListBox}">
+            <ListBox.ItemTemplate>
+                <DataTemplate>
+                    <StackPanel>
+                        <TextBlock Text="{Binding Name}" ></TextBlock>
+                        <TextBlock Text="{Binding Supports}" TextWrapping="Wrap" Foreground="{DynamicResource ModernForeground2}"
+                                   FontStyle="Italic"/>
+                    </StackPanel>
+                </DataTemplate>
+            </ListBox.ItemTemplate></ListBox>
 
         <Label Content="Cap values" Grid.Column="2"></Label>
         <ListBox x:Name="CapDetailList" Grid.Row="1" Grid.Column="2" MinWidth="100"

Tests/Tester.WPF/MainWindow.xaml.cs

@@ -92,7 +92,8 @@ namespace Tester.WPF
                 {
                     var caps = _twainVM.SupportedCaps.Select(o => new CapVM
                     {
-                        Cap = o
+                        Cap = o,
+                        Supports = _twainVM.GetCapSupport(o)
                     }).OrderBy(o => o.Name).ToList();
                     CapList.ItemsSource = caps;
                 }

Tests/Tester.WPF/ViewModels/CapVM.cs

@@ -21,13 +21,7 @@ namespace Tester.WPF
             }
         }
 
-        //public void SupportedOperations
+        public QuerySupport Supports { get; set; }
-        //{
-        //    get
-        //    {
-
-        //    }
-        //}
 
         public override string ToString()
         {