Aspect ratio detection code moved to Models

Author: apdevelop

Src/ScreenGrid.Models/AspectRatioDetector.cs

@@ -0,0 +1,67 @@
+namespace ScreenGrid.Models
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Globalization;
+    using System.Linq;
+
+    public static class AspectRatioDetector
+    {
+        // TODO: add tests
+
+        /// <summary>
+        /// Common aspect ratios
+        /// https://en.wikipedia.org/wiki/Aspect_ratio_%28image%29
+        /// </summary>
+        private static Dictionary<double, string> commonAspectRatios = new Dictionary<double, string>()
+        {
+            // TODO: create class with separated properties
+            // TODO: add descriptions for displaying in tooltip
+            { 1.0, "1:1" },
+            { 6.0 / 5.0, "6:5" },
+            { 5.0 / 4.0, "5:4" },
+            { 4.0 / 3.0, "4:3" },
+            { 11.0 / 8.0, "11:8" },
+            { Math.Sqrt(2.0), "1.41:1" }, // ISO 216 paper sizes
+            { 1.43, "1.43:1" },
+            { 3.0 / 2.0, "3:2" },
+            { 16.0 / 10.0, "16:10" }, // The golden ratio
+            { 1.618, "16.18:10" },
+            { 5.0 / 3.0, "5:3" },
+            { 16.0 / 9.0, "16:9" },
+            { 1.85, "1.85:1" },
+            { 2.35, "2.35:1" },
+            { 2.39, "2.39:1" },
+            { 2.414, "2.414:1" }, // The silver ratio
+            { 2.76, "2.76:1" },
+        };
+
+        public static string DetectCommonAspectRatio(double ratio)
+        {
+            const double Tolerance = 0.01;
+
+            if (ratio >= 1.0)
+            {
+                // Horizontal
+                var nearest = commonAspectRatios.OrderBy(kvp => Math.Abs(kvp.Key - ratio)).First();
+                if (Math.Abs(nearest.Key - ratio) < Tolerance)
+                {
+                    return nearest.Value;
+                }
+            }
+            else
+            {
+                // Vertical
+                ratio = 1.0 / ratio;
+                var nearest = commonAspectRatios.OrderBy(kvp => Math.Abs(kvp.Key - ratio)).First();
+                if (Math.Abs(nearest.Key - ratio) < Tolerance)
+                {
+                    var arr = nearest.Value.Split(':');
+                    return String.Format(CultureInfo.InvariantCulture, "{0}:{1}", arr[1], arr[0]);
+                }
+            }
+
+            return String.Empty;
+        }
+    }
+}

Src/ScreenGrid.Models/ScreenGrid.Models.csproj

@@ -41,6 +41,7 @@
     <Compile Include="AppsInterop\NativeWindow.cs" />
     <Compile Include="AppsInterop\OctaneRenderWindow.cs" />
     <Compile Include="AppsInterop\PhotoViewerWindow.cs" />
+    <Compile Include="AspectRatioDetector.cs" />
     <Compile Include="FlatImage.cs" />
     <Compile Include="Geometry\Line.cs" />
     <Compile Include="Geometry\Point.cs" />

Src/ScreenGrid.ViewModels/ScreenGridViewModel.cs

@@ -293,64 +293,12 @@ private Tuple<int, int> ImageSize
             }
         }
 
-        // TODO: move code to Models, add tests
-
-        /// <summary>
-        /// Common aspect ratios
-        /// https://en.wikipedia.org/wiki/Aspect_ratio_%28image%29
-        /// </summary>
-        private static Dictionary<double, string> CommonAspectRatios = new Dictionary<double, string>()
-        {
-            // TODO: create class with separated properties
-            // TODO: add descriptions for displaying in tooltip
-            { 1.0, "1:1" },
-            { 6.0 / 5.0, "6:5" },
-            { 5.0 / 4.0, "5:4" },
-            { 4.0 / 3.0, "4:3" },
-            { 11.0 / 8.0, "11:8" },
-            { Math.Sqrt(2.0), "1.41:1" }, // ISO 216 paper sizes
-            { 1.43, "1.43:1" },
-            { 3.0 / 2.0, "3:2" },
-            { 16.0 / 10.0, "16:10" }, // The golden ratio
-            { 1.618, "16.18:10" },
-            { 5.0 / 3.0, "5:3" },
-            { 16.0 / 9.0, "16:9" },
-            { 1.85, "1.85:1" },
-            { 2.35, "2.35:1" },
-            { 2.39, "2.39:1" },
-            { 2.414, "2.414:1" }, // The silver ratio
-            { 2.76, "2.76:1" },
-        };
-
         private string AspectRatio
         {
             get
             {
-                const double tolerance = 0.01;
                 var ratio = ((double)this.ImageSize.Item1) / ((double)this.ImageSize.Item2);
-
-                if (ratio >= 1.0)
-                {
-                    // Horizontal
-                    var nearest = CommonAspectRatios.OrderBy(kvp => Math.Abs(kvp.Key - ratio)).First();
-                    if (Math.Abs(nearest.Key - ratio) < tolerance)
-                    {
-                        return nearest.Value;
-                    }
-                }
-                else
-                {
-                    // Vertical
-                    ratio = 1.0 / ratio;
-                    var nearest = CommonAspectRatios.OrderBy(kvp => Math.Abs(kvp.Key - ratio)).First();
-                    if (Math.Abs(nearest.Key - ratio) < tolerance)
-                    {
-                        var arr = nearest.Value.Split(':');
-                        return String.Format(CultureInfo.InvariantCulture, "{0}:{1}", arr[1], arr[0]);
-                    }
-                }
-
-                return String.Empty;
+                return Models.AspectRatioDetector.DetectCommonAspectRatio(ratio);
             }
         }