Road to v1 begins!

NTwain/Internals/Extensions.cs

@@ -0,0 +1,43 @@
+using NTwain.Data;
+using NTwain.Properties;
+using System;
+
+namespace NTwain.Internals
+{
+    static class Extensions
+    {
+        /// <summary>
+        /// Verifies the string length is under the maximum length
+        /// and throws <see cref="ArgumentException"/> if violated.
+        /// </summary>
+        /// <param name="value">The value.</param>
+        /// <param name="maxLength">The maximum length.</param>
+        public static void VerifyLengthUnder(this string value, int maxLength)
+        {
+            if (value != null && value.Length > maxLength)
+                throw new ArgumentException(Resources.MaxStringLengthExceeded);
+        }
+
+
+        /// <summary>
+        /// Verifies the session is within the specified state range (inclusive). Throws
+        /// <see cref="TwainStateException" /> if violated.
+        /// </summary>
+        /// <param name="session">The session.</param>
+        /// <param name="allowedMinimum">The allowed minimum.</param>
+        /// <param name="allowedMaximum">The allowed maximum.</param>
+        /// <param name="group">The triplet data group.</param>
+        /// <param name="dataArgumentType">The triplet data argument type.</param>
+        /// <param name="message">The triplet message.</param>
+        /// <exception cref="TwainStateException"></exception>
+        public static void VerifyState(this ITwainStateInternal session, int allowedMinimum, int allowedMaximum, DataGroups group, DataArgumentType dataArgumentType, Message message)
+        {
+            if (session.EnforceState && (session.State < allowedMinimum || session.State > allowedMaximum))
+            {
+                throw new TwainStateException(session.State, allowedMinimum, allowedMaximum, group, dataArgumentType, message,
+                    string.Format("TWAIN state {0} does not match required range {1}-{2} for operation {3}-{4}-{5}.",
+                    session.State, allowedMinimum, allowedMaximum, group, dataArgumentType, message));
+            }
+        }
+    }
+}