Added scales

Elwig/Helpers/Weighing/IScale.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Elwig.Helpers.Weighing {
+    /// <summary>
+    /// Interface for controlling a industrial scale
+    /// </summary>
+    public interface IScale : IDisposable {
+        /// <summary>
+        /// Manufacturer of the scale
+        /// </summary>
+        string Manufacturer { get; }
+
+        /// <summary>
+        /// Model of the scale
+        /// </summary>
+        string Model { get; }
+
+        /// <summary>
+        /// Unique number of the scale
+        /// </summary>
+        int ScaleNr { get; }
+
+        /// <summary>
+        /// Internal identifying number of the scale in its system
+        /// </summary>
+        int InternalScaleNr { get; }
+
+        /// <summary>
+        /// Indicates if the scale is currently processing a request or not
+        /// </summary>
+        bool IsReady { get; }
+
+        /// <summary>
+        /// Indicates if the the clearance for filling the scale container has been granted
+        /// </summary>
+        bool HasFillingClearance { get; }
+
+        /// <summary>
+        /// Get the current weight on the scale without performing a weighing process
+        /// </summary>
+        /// <returns>Result of the weighing process (probably without a weighing id)</returns>
+        Task<WeighingResult> GetCurrentWeight();
+
+        /// <summary>
+        /// Perform a weighing process
+        /// </summary>
+        /// <returns>Result of the weighing process (including a weighing id)</returns>
+        Task<WeighingResult> Weigh();
+
+        /// <summary>
+        /// Empty the scale container or grant clearance to do so
+        /// </summary>
+        Task Empty();
+
+        /// <summary>
+        /// Grant clearance to fill the scale container
+        /// </summary>
+        Task GrantFillingClearance();
+
+        /// <summary>
+        /// Revoke clearance to fill the scale container
+        /// </summary>
+        Task RevokeFillingClearance();
+    }
+}