Changeset 2 for swappable message loop hook implementations.

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);
+    }
+
+
+}