Separated nesting logic from UI

CutToLength/BestFitEngine.cs

@@ -0,0 +1,73 @@
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
+
+namespace CutToLength
+{
+    public class BestFitEngine : IEngine
+    {
+        public double StockLength { get; set; }
+
+        public Tool CutTool { get; set; }
+
+        public List<Bin> GetResults(List<BinItem> items)
+        {
+            var items2 = items.OrderByDescending(i => i.Length);
+            var bins = new List<Bin>();
+            var length = StockLength;
+
+            foreach (var item in items2)
+            {
+                Bin best_bin;
+
+                if (!FindBin(bins.ToArray(), item.Length, out best_bin))
+                {
+                    if (item.Length > length)
+                        continue;
+
+                    best_bin = CreateBin();
+                    bins.Add(best_bin);
+                }
+
+                best_bin.Items.Add(item);
+            }
+
+            return bins;
+        }
+
+        private Bin CreateBin()
+        {
+            var length = StockLength;
+            var spacing = CutTool.Kerf;
+
+            return new Bin(length)
+            {
+                Spacing = spacing
+            };
+        }
+
+        private static bool FindBin(IEnumerable<Bin> bins, double length, out Bin found)
+        {
+            found = null;
+
+            foreach (var bin in bins)
+            {
+                if (bin.RemainingLength < length)
+                    continue;
+
+                if (found == null)
+                    found = bin;
+
+                if (bin.RemainingLength < found.RemainingLength)
+                    found = bin;
+            }
+
+            return (found != null);
+        }
+    }
+
+    public interface IEngine
+    {
+        List<Bin> GetResults(List<BinItem> items);
+    }
+}

CutToLength/CutToLength.csproj

@@ -52,6 +52,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="BestFitEngine.cs" />
     <Compile Include="Bin.cs" />
     <Compile Include="BinItem.cs" />
     <Compile Include="BinLayoutView.cs">

CutToLength/MainForm.cs

@@ -3,7 +3,6 @@ using SimpleExpressionEvaluator;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Data;
 using System.Diagnostics;
 using System.Drawing;
 using System.IO;
@@ -129,7 +128,12 @@ namespace CutToLength
 
         private void Run()
         {
-            var bins = GetResults();
+            var engine = new BestFitEngine();
+            engine.CutTool = GetSelectedTool();
+            engine.StockLength = StockLengthInches;
+
+            var items = GetItems();
+            var bins = engine.GetResults(items);
 
             var form = new ResultsForm();
             form.Bins = bins;
@@ -144,31 +148,6 @@ namespace CutToLength
             //}
         }
 
-        private List<Bin> GetResults()
-        {
-            var items2 = GetItems().OrderByDescending(i => i.Length);
-            var bins = new List<Bin>();
-            var length = StockLengthInches;
-
-            foreach (var item in items2)
-            {
-                Bin best_bin;
-
-                if (!FindBin(bins.ToArray(), item.Length, out best_bin))
-                {
-                    if (item.Length > length)
-                        continue;
-
-                    best_bin = CreateBin();
-                    bins.Add(best_bin);
-                }
-
-                best_bin.Items.Add(item);
-            }
-
-            return bins;
-        }
-
         private List<BinItem> GetItems()
         {
             var items2 = new List<BinItem>();
@@ -191,17 +170,6 @@ namespace CutToLength
             return items2;
         }
 
-        private Bin CreateBin()
-        {
-            var length = StockLengthInches;
-            var spacing = GetSelectedTool().Kerf;
-
-            return new Bin(length)
-            {
-                Spacing = spacing
-            };
-        }
-
         public Tool GetSelectedTool()
         {
             return comboBox1.SelectedItem as Tool;
@@ -235,25 +203,6 @@ namespace CutToLength
             Process.Start(file);
         }
 
-        private static bool FindBin(IEnumerable<Bin> bins, double length, out Bin found)
-        {
-            found = null;
-
-            foreach (var bin in bins)
-            {
-                if (bin.RemainingLength < length)
-                    continue;
-
-                if (found == null)
-                    found = bin;
-
-                if (bin.RemainingLength < found.RemainingLength)
-                    found = bin;
-            }
-
-            return (found != null);
-        }
-
         private void toolStripButton1_Click(object sender, EventArgs e)
         {
             Open();