Changeset 2 for swappable message loop hook implementations.

NTwain/Internals/ITwainSessionInternal.cs

@@ -14,7 +14,7 @@ namespace NTwain.Internals
         /// <returns></returns>
         TWIdentity AppId { get; }
 
-        MessageLoop SelfMessageLoop { get; }
+        MessageLoopHook MessageLoopHook { get; }
 
         /// <summary>
         /// Gets or sets a value indicating whether calls to triplets will verify the current twain session state.

NTwain/Internals/IWinMessageFilter.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NTwain.Internals
+{
+    /// <summary>
+    /// Interface for checking whether messages from WndProc is a TWAIN message and is handled
+    /// internally.
+    /// </summary>
+    interface IWinMessageFilter
+    {
+        /// <summary>
+        /// Checks and handle the message if it's a TWAIN message.
+        /// </summary>
+        /// <param name="hwnd">The window handle.</param>
+        /// <param name="msg">The message.</param>
+        /// <param name="wParam">The w parameter.</param>
+        /// <param name="lParam">The l parameter.</param>
+        /// <returns>true if handled internally.</returns>
+        bool IsTwainMessage(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam);
+    }
+
+
+}

NTwain/Internals/InternalMessageLoopHook.cs

@@ -1,28 +1,27 @@
 using NTwain.Properties;
-using NTwain.Triplets;
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
+using System.Text;
 using System.Threading;
 using System.Windows.Threading;
 
 namespace NTwain.Internals
 {
-    /// <summary>
-    /// Provides a message loop for old TWAIN to post or new TWAIN to synchronize callbacks.
-    /// </summary>
-    class MessageLoop
+    sealed class InternalMessageLoopHook : MessageLoopHook
     {
         Dispatcher _dispatcher;
         WindowsHook _hook;
 
-        public void Stop()
+        internal override void Stop()
         {
             if (_dispatcher != null)
             {
                 _dispatcher.InvokeShutdown();
             }
         }
-        public void Start(IWinMessageFilter filter)
+        internal override void Start(IWinMessageFilter filter)
         {
             if (_dispatcher == null)
             {
@@ -36,6 +35,7 @@ namespace NTwain.Internals
                         if (!Platform.IsOnMono)
                         {
                             _hook = new WindowsHook(filter);
+                            Handle = _hook.Handle;
                         }
                         hack.Set();
                         Dispatcher.Run();
@@ -55,22 +55,14 @@ namespace NTwain.Internals
             }
         }
 
-        public IntPtr LoopHandle
-        {
-            get
-            {
-                return _hook == null ? IntPtr.Zero : _hook.Handle;
-            }
-        }
-
-        public void BeginInvoke(Action action)
+        internal override void BeginInvoke(Action action)
         {
             if (_dispatcher == null) { throw new InvalidOperationException(Resources.MsgLoopUnavailble); }
 
             _dispatcher.BeginInvoke(DispatcherPriority.Normal, action);
         }
 
-        public void Invoke(Action action)
+        internal override void Invoke(Action action)
         {
             if (_dispatcher == null) { throw new InvalidOperationException(Resources.MsgLoopUnavailble); }