Added custom cap value container types.

src/NTwain/Data/Containers.cs

@@ -0,0 +1,122 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NTwain.Data
+{
+    // use custom containers for twain container types to not have to worry about memory mgmt
+    // after giving it to consumers
+
+    /// <summary>
+    /// Container for one value.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    public struct OneValue<T>
+    {
+        /// <summary>
+        /// The type of the item.
+        /// </summary>
+        public ItemType Type;
+
+        /// <summary>
+        /// The value.
+        /// </summary>
+        public T Value;
+    }
+
+    /// <summary>
+    /// Stores a group of associated individual values for a capability.
+    /// The values need have no relationship to one another aside from 
+    /// being used to describe the same "value" of the capability
+    /// </summary>
+    public struct ArrayValue<T>
+    {
+        /// <summary>
+        /// The type of items in the array.
+        /// </summary>
+        public ItemType Type;
+
+        /// <summary>
+        /// Array of values.
+        /// </summary>
+        public T[] ItemList;
+    }
+
+    /// <summary>
+    /// An enumeration stores a list of individual values, with one of the items designated as the current
+    /// value. There is no required order to the values in the list.
+    /// </summary>
+    public struct EnumValue<T>
+    {
+        /// <summary>
+        /// Gets the byte offset of the item list from a Ptr to the first item.
+        /// </summary>
+        internal const int ValuesOffset = 14;
+
+        /// <summary>
+        /// The type of items in the enumerated list.
+        /// </summary>
+        public ItemType Type;
+
+        /// <summary>
+        /// The item number, or index (zero-based) into 
+        /// <see cref="ItemList"/>, of the "current"
+        /// value for the capability.
+        /// </summary>
+        public int CurrentIndex;
+
+        /// <summary>
+        /// The item number, or index (zero-based) into 
+        /// <see cref="ItemList"/>, of the "power-on"
+        /// value for the capability.
+        /// </summary>
+        public int DefaultIndex;
+
+        /// <summary>
+        /// The enumerated value list.
+        /// </summary>
+        public T[] ItemList;
+    }
+
+    /// <summary>
+    /// Container for a range of values.
+    /// </summary>
+    public struct RangeValue
+    {
+        /// <summary>
+        /// The type of items in the container.
+        /// </summary>
+        public ItemType Type;
+
+        /// <summary>
+        /// The least positive/most negative value of the range.
+        /// </summary>
+        public int Min;
+
+        /// <summary>
+        /// The most positive/least negative value of the range.
+        /// </summary>
+        public int Max;
+
+        /// <summary>
+        /// The delta between two adjacent values of the range.
+        /// e.g. Item2 - Item1 = StepSize;
+        /// </summary>
+        public int StepSize;
+
+        /// <summary>
+        /// The device’s "power-on" value for the capability. If the application is
+        /// performing a MSG_SET operation and isn’t sure what the default
+        /// value is, set this field to <see cref="TwainConst.DontCare32"/>.
+        /// </summary>
+        public int DefaultValue;
+
+        /// <summary>
+        /// The value to which the device (or its user interface) is currently set to
+        /// for the capability.
+        /// </summary>
+        public int CurrentValue;
+    }
+}

src/NTwain/Data/TwainTypes.cs

@@ -74,9 +74,9 @@ namespace NTwain.Data
     partial class TW_ARRAY
     {
         // TODO: _itemType in mac is TW_UINT32?
-        TW_UINT16 _itemType;
+        public TW_UINT16 ItemType;
-        TW_UINT32 _numItems;
+        public TW_UINT32 NumItems;
-        object[] _itemList;
+        public IntPtr ItemList;
     }
 
     [StructLayout(LayoutKind.Sequential, Pack = 2),
@@ -181,12 +181,12 @@ namespace NTwain.Data
     partial class TW_ENUMERATION
     {
         // TODO: _itemType in mac is TW_UINT32?
-        TW_UINT16 _itemType;
+        public TW_UINT16 ItemType;
         // TODO: these are UInt64 in linux 64 bit?
-        TW_UINT32 _numItems;
+        public TW_UINT32 NumItems;
-        TW_UINT32 _currentIndex;
+        public TW_UINT32 CurrentIndex;
-        TW_UINT32 _defaultIndex;
+        public TW_UINT32 DefaultIndex;
-        object[] _itemList;
+        public IntPtr ItemList;
     }
 
     [StructLayout(LayoutKind.Sequential, Pack = 2)]
@@ -431,8 +431,8 @@ namespace NTwain.Data
     partial class TW_ONEVALUE
     {
         // TODO: mac is different?
-        TW_UINT16 _itemType;
+        public TW_UINT16 ItemType;
-        TW_UINT32 _item;
+        public TW_UINT32 Item;
     }
 
     [StructLayout(LayoutKind.Sequential, Pack = 2)]
@@ -468,12 +468,12 @@ namespace NTwain.Data
     partial class TW_RANGE
     {
         // TODO: mac & linux are different?
-        TW_UINT16 _itemType;
+        public TW_UINT16 ItemType;
-        TW_UINT32 _minValue;
+        public TW_UINT32 MinValue;
-        TW_UINT32 _maxValue;
+        public TW_UINT32 MaxValue;
-        TW_UINT32 _stepSize;
+        public TW_UINT32 StepSize;
-        TW_UINT32 _defaultValue;
+        public TW_UINT32 DefaultValue;
-        TW_UINT32 _currentValue;
+        public TW_UINT32 CurrentValue;
     }
 
     //[StructLayout(LayoutKind.Sequential, Pack = 2)]

src/NTwain/Data/TwainTypesExtended.cs

@@ -526,39 +526,6 @@ namespace NTwain.Data
         }
     }
 
-    //    /// <summary>
-    //    /// Stores a group of associated individual values for a capability.
-    //    /// The values need have no relationship to one another aside from 
-    //    /// being used to describe the same "value" of the capability
-    //    /// </summary>
-    //    public partial class TW_ARRAY
-    //    {
-    //        /// <summary>
-    //        /// The type of items in the array. All items in the array have the same size.
-    //        /// </summary>
-    //        public ItemType ItemType { get { return (ItemType)_itemType; } set { _itemType = (ushort)value; } }
-
-    //        ///// <summary>
-    //        ///// How many items are in the array.
-    //        ///// </summary>
-    //        //public int Count { get { return (int)_numItems; } set { _numItems = (uint)value; } }
-
-    //        /// <summary>
-    //        /// Array of ItemType values starts here.
-    //        /// </summary>
-
-    //        public object[] ItemList
-    //        {
-    //            get { return _itemList; }
-    //            set
-    //            {
-    //                _itemList = value;
-    //                if (value != null) { _numItems = (uint)value.Length; }
-    //                else { _numItems = 0; }
-    //            }
-    //        }
-    //    }
-
     /// <summary>
     /// Used to get audio info.
     /// </summary>
@@ -1120,52 +1087,6 @@ namespace NTwain.Data
         #endregion
     }
 
-    //    /// <summary>
-    //    /// An enumeration stores a list of individual values, with one of the items designated as the current
-    //    /// value. There is no required order to the values in the list.
-    //    /// </summary>
-    //    public partial class TW_ENUMERATION
-    //    {
-    //        /// <summary>
-    //        /// The type of items in the enumerated list. All items in the array have the same size.
-    //        /// </summary>
-    //        public ItemType ItemType { get { return (ItemType)_itemType; } set { _itemType = (ushort)value; } }
-    //        ///// <summary>
-    //        ///// How many items are in the enumeration.
-    //        ///// </summary>
-    //        //public int Count { get { return (int)_numItems; } set { _numItems = (uint)value; } }
-    //        /// <summary>
-    //        /// The item number, or index (zero-based) into <see cref="ItemList"/>, of the "current"
-    //        /// value for the capability.
-    //        /// </summary>
-    //        public int CurrentIndex { get { return (int)_currentIndex; } set { _currentIndex = (uint)value; } }
-    //        /// <summary>
-    //        /// The item number, or index (zero-based) into <see cref="ItemList"/>, of the "power-on"
-    //        /// value for the capability.
-    //        /// </summary>
-    //        public int DefaultIndex { get { return (int)_defaultIndex; } set { _defaultIndex = (uint)value; } }
-    //        /// <summary>
-    //        /// The enumerated list: one value resides within each array element.
-    //        /// </summary>
-
-    //        public object[] ItemList
-    //        {
-    //            get { return _itemList; }
-    //            set
-    //            {
-    //                _itemList = value;
-    //                if (value != null) { _numItems = (uint)value.Length; }
-    //                else { _numItems = 0; }
-    //            }
-    //        }
-
-    //        /// <summary>
-    //        /// Gets the byte offset of the item list from a Ptr to the first item.
-    //        /// </summary>
-    //        internal const int ItemOffset = 14;
-    //    }
-
-
     //    /// <summary>
     //    /// This structure is used to pass specific information between the data source and the application
     //    /// through <see cref="TW_EXTIMAGEINFO"/>.
@@ -1954,21 +1875,6 @@ namespace NTwain.Data
         public uint SheetCount => _sheetCount;
     }
 
-    //    /// <summary>
-    //    /// Container for one value.
-    //    /// </summary>
-    //    public partial class TW_ONEVALUE
-    //    {
-    //        /// <summary>
-    //        /// The type of the item.
-    //        /// </summary>
-    //        public ItemType ItemType { get { return (ItemType)_itemType; } set { _itemType = (ushort)value; } }
-    //        /// <summary>
-    //        /// The value.
-    //        /// </summary>
-    //        public uint Item { get { return _item; } set { _item = value; } }
-    //    }
-
 
     /// <summary>
     /// This structure holds the color palette information for buffered memory transfers of type
@@ -2053,41 +1959,6 @@ namespace NTwain.Data
     }
     
 
-    //    /// <summary>
-    //    /// Container for a range of values.
-    //    /// </summary>
-    //    public partial class TW_RANGE
-    //    {
-    //        /// <summary>
-    //        /// The type of items in the list.
-    //        /// </summary>
-    //        public ItemType ItemType { get { return (ItemType)_itemType; } set { _itemType = (ushort)value; } }
-    //        /// <summary>
-    //        /// The least positive/most negative value of the range.
-    //        /// </summary>
-    //        public uint MinValue { get { return _minValue; } set { _minValue = value; } }
-    //        /// <summary>
-    //        /// The most positive/least negative value of the range.
-    //        /// </summary>
-    //        public uint MaxValue { get { return _maxValue; } set { _maxValue = value; } }
-    //        /// <summary>
-    //        /// The delta between two adjacent values of the range.
-    //        /// e.g. Item2 - Item1 = StepSize;
-    //        /// </summary>
-    //        public uint StepSize { get { return _stepSize; } set { _stepSize = value; } }
-    //        /// <summary>
-    //        /// The device’s "power-on" value for the capability. If the application is
-    //        /// performing a MSG_SET operation and isn’t sure what the default
-    //        /// value is, set this field to <see cref="TwainConst.DontCare32"/>.
-    //        /// </summary>
-    //        public uint DefaultValue { get { return _defaultValue; } set { _defaultValue = value; } }
-    //        /// <summary>
-    //        /// The value to which the device (or its user interface) is currently set to
-    //        /// for the capability.
-    //        /// </summary>
-    //        public uint CurrentValue { get { return _currentValue; } set { _currentValue = value; } }
-    //    }
-
     //    ///// <summary>
     //    ///// This structure is used by the application to specify a set of mapping values to be applied to RGB
     //    ///// color data. Use this structure for RGB data whose bit depth is up to, and including, 8-bits.

src/NTwain/TwainSession.cs

@@ -297,7 +297,7 @@ namespace NTwain
         /// </returns>
         public override string ToString()
         {
-            return State.ToString()
+            return State.ToString();
         }
     }
 }