Some name-breaking changes so master is now v3. V2 will continue to be the code on nuget for now.

NTwain/PlatformInfo.cs

@@ -0,0 +1,134 @@
+using NTwain.Triplets;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace NTwain
+{
+    /// <summary>
+    /// Contains various platform requirements and conditions for TWAIN.
+    /// </summary>
+    public class PlatformInfo : IPlatformInfo
+    {
+        internal static readonly PlatformInfo __global = new PlatformInfo();
+        /// <summary>
+        /// Gets the current platform info related to TWAIN.
+        /// </summary>
+        /// <value>
+        /// The current info.
+        /// </value>
+        public static IPlatformInfo Current { get { return __global; } }
+
+
+        PlatformInfo()
+        {
+            IsApp64bit = IntPtr.Size == 8;
+
+            IsOnMono = Type.GetType("Mono.Runtime") != null;
+            IsWindows = Environment.OSVersion.Platform == PlatformID.Win32NT;
+            IsLinux = Environment.OSVersion.Platform == PlatformID.Unix;
+
+            if (IsWindows)
+            {
+                var newDsmPath = Path.Combine(Environment.SystemDirectory, Dsm.WIN_NEW_DSM_NAME);
+                var oldDsmPath = Path.Combine(Environment.SystemDirectory, Dsm.WIN_OLD_DSM_NAME);
+
+                if (IsApp64bit)
+                {
+                    ExpectedDsmPath = newDsmPath;
+                    IsSupported = DsmExists = File.Exists(ExpectedDsmPath);
+                    UseNewWinDSM = true;
+                }
+                else
+                {
+                    if (File.Exists(newDsmPath))
+                    {
+                        ExpectedDsmPath = newDsmPath;
+                        UseNewWinDSM = IsSupported = DsmExists = true;
+                    }
+                    else
+                    {
+                        ExpectedDsmPath = oldDsmPath;
+                        IsSupported = DsmExists = File.Exists(ExpectedDsmPath);
+                    }
+                }
+            }
+            else if (IsLinux)
+            {
+                ExpectedDsmPath = Dsm.LINUX_DSM_PATH;
+                DsmExists = File.Exists(ExpectedDsmPath);
+                IsSupported = DsmExists && IsOnMono;
+            }
+            else
+            {
+                // mac? not gonna happen
+            }
+
+            _defaultMemManager = new WinMemoryManager();
+        }
+
+        internal readonly bool UseNewWinDSM;
+        internal readonly bool IsOnMono;
+        internal readonly bool IsWindows;
+        internal readonly bool IsLinux;
+
+        /// <summary>
+        /// Gets a value indicating whether the application is running in 64-bit.
+        /// </summary>
+        /// <value>
+        /// <c>true</c> if the application is 64-bit; otherwise, <c>false</c>.
+        /// </value>
+        public bool IsApp64bit { get; private set; }
+
+        /// <summary>
+        /// Gets a value indicating whether the applicable TWAIN DSM library exists in the operating system.
+        /// </summary>
+        /// <value>
+        ///   <c>true</c> if the TWAIN DSM; otherwise, <c>false</c>.
+        /// </value>
+        public bool DsmExists { get; private set; }
+
+        /// <summary>
+        /// Gets the expected TWAIN DSM dll path.
+        /// </summary>
+        /// <value>
+        /// The expected DSM path.
+        /// </value>
+        public string ExpectedDsmPath { get; private set; }
+
+        /// <summary>
+        /// Gets a value indicating whether this library is supported on current OS.
+        /// Check the other platform properties to determine the reason if this is false.
+        /// </summary>
+        /// <value>
+        /// <c>true</c> if this library is supported; otherwise, <c>false</c>.
+        /// </value>
+        public bool IsSupported { get; private set; }
+
+
+        readonly IMemoryManager _defaultMemManager;
+        IMemoryManager _specifiedMemManager;
+
+        /// <summary>
+        /// Gets the <see cref="IMemoryManager"/> for communicating with data sources.
+        /// This should only be used when a <see cref="TwainSession"/> is open.
+        /// </summary>
+        /// <value>
+        /// The memory manager.
+        /// </value>
+        public IMemoryManager MemoryManager
+        {
+            get
+            {
+                if (_specifiedMemManager == null) { return _defaultMemManager; }
+                return _specifiedMemManager;
+            }
+            internal set
+            {
+                _specifiedMemManager = value;
+            }
+        }
+    }
+}