From 1ce7c5caf5905c51812455db25ba82796d572b8a Mon Sep 17 00:00:00 2001
From: soukoku <yinchun.wang@gmail.com>
Date: Wed, 7 Jan 2015 21:34:56 -0500
Subject: [PATCH] Added named state enum.

---
 NTwain.Net35/NTwain.Net35.csproj |  3 +++
 NTwain/ITwainSession.cs          |  7 ++++++
 NTwain/NTwain.csproj             |  1 +
 NTwain/State.cs                  | 43 ++++++++++++++++++++++++++++++++
 NTwain/TwainSession.cs           | 21 ++++++++++++++--
 5 files changed, 73 insertions(+), 2 deletions(-)
 create mode 100644 NTwain/State.cs

diff --git a/NTwain.Net35/NTwain.Net35.csproj b/NTwain.Net35/NTwain.Net35.csproj
index efa01ff..9ebbb92 100644
--- a/NTwain.Net35/NTwain.Net35.csproj
+++ b/NTwain.Net35/NTwain.Net35.csproj
@@ -156,6 +156,9 @@
     <Compile Include="..\NTwain\SourceEnableMode.cs">
       <Link>SourceEnableMode.cs</Link>
     </Compile>
+    <Compile Include="..\NTwain\State.cs">
+      <Link>State.cs</Link>
+    </Compile>
     <Compile Include="..\NTwain\TransferErrorEventArgs.cs">
       <Link>TransferErrorEventArgs.cs</Link>
     </Compile>
diff --git a/NTwain/ITwainSession.cs b/NTwain/ITwainSession.cs
index 4d922f4..cdaf2a3 100644
--- a/NTwain/ITwainSession.cs
+++ b/NTwain/ITwainSession.cs
@@ -57,6 +57,13 @@ namespace NTwain
         /// <value>The state.</value>
         int State { get; }
 
+        /// <summary>
+        /// Gets the named state value as defined by the TWAIN spec.
+        /// </summary>
+        /// <value>
+        /// The state.
+        /// </value>
+        State StateEx { get; }
 
         /// <summary>
         /// Quick flag to check if the DSM has been opened.
diff --git a/NTwain/NTwain.csproj b/NTwain/NTwain.csproj
index 2dc6d56..6a1fd8f 100644
--- a/NTwain/NTwain.csproj
+++ b/NTwain/NTwain.csproj
@@ -88,6 +88,7 @@
     </Compile>
     <Compile Include="Properties\VersionInfo.cs" />
     <Compile Include="Internals\TentativeStateCommitable.cs" />
+    <Compile Include="State.cs" />
     <Compile Include="TransferErrorEventArgs.cs" />
     <Compile Include="TransferReadyEventArgs.cs" />
     <Compile Include="Triplets\DGControl\DGControl.Callback2.cs" />
diff --git a/NTwain/State.cs b/NTwain/State.cs
new file mode 100644
index 0000000..a37483c
--- /dev/null
+++ b/NTwain/State.cs
@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NTwain
+{
+    /// <summary>
+    /// The logical state of a TWAIN session.
+    /// </summary>
+    public enum State
+    {
+        /// <summary>
+        /// The starting state, corresponds to state 1.
+        /// </summary>
+        DsmUnloaded = 1,
+        /// <summary>
+        /// The DSM library has been loaded, corresponds to state 2.
+        /// </summary>
+        DsmLoaded = 2,
+        /// <summary>
+        /// The DSM has been opened, corresponds to state 3.
+        /// </summary>
+        DsmOpened = 3,
+        /// <summary>
+        /// A data source has been opened, corresponds to state 4.
+        /// </summary>
+        SourceOpened = 4,
+        /// <summary>
+        /// A data source has been enabled, corresponds to state 5.
+        /// </summary>
+        SourceEnabled = 5,
+        /// <summary>
+        /// Data is ready for transfer from the source, corresponds to state 6.
+        /// </summary>
+        TransferReady = 6,
+        /// <summary>
+        /// Data is being transferred, corresponds to state 7.
+        /// </summary>
+        Transferring = 7
+    };
+
+}
diff --git a/NTwain/TwainSession.cs b/NTwain/TwainSession.cs
index a22bba4..0d92a4b 100644
--- a/NTwain/TwainSession.cs
+++ b/NTwain/TwainSession.cs
@@ -41,7 +41,10 @@ namespace NTwain
 
             _appId = appId;
             _ownedSources = new Dictionary<string, DataSource>();
-            ((ITwainSessionInternal)this).ChangeState(1, false);
+            if (PlatformInfo.Current.IsSupported)
+            {
+                ((ITwainSessionInternal)this).ChangeState(2, false);
+            }
 #if DEBUG
             // defaults to false on release since it's only useful during dev
             EnforceState = true;
@@ -144,7 +147,7 @@ namespace NTwain
             return null;
         }
 
-        int _state;
+        int _state = 1;
         /// <summary>
         /// Gets the current state number as defined by the TWAIN spec.
         /// </summary>
@@ -165,6 +168,20 @@ namespace NTwain
             }
         }
 
+        /// <summary>
+        /// Gets the named state value as defined by the TWAIN spec.
+        /// </summary>
+        /// <value>
+        /// The state.
+        /// </value>
+        public State StateEx
+        {
+            get
+            {
+                return (State)_state;
+            }
+        }
+
         /// <summary>
         /// Quick flag to check if the DSM has been opened.
         /// </summary>