Fixes #14 by searching for best possible match for frame in ".ico" fi…

…les or ImageSource which inherit from BitmapFrame when ConverterParameter is set

Fluent/Converters/ObjectToImageConverter.cs

@@ -1,8 +1,11 @@
 namespace Fluent.Converters
 {
     using System;
+    using System.Diagnostics;
     using System.Globalization;
+    using System.Linq;
     using System.Net.Cache;
+    using System.Windows;
     using System.Windows.Controls;
     using System.Windows.Data;
     using System.Windows.Media;
@@ -24,26 +27,39 @@ public class ObjectToImageConverter : IValueConverter
         /// <param name="value">The value produced by the binding source.</param><param name="targetType">The type of the binding target property.</param><param name="parameter">The converter parameter to use.</param><param name="culture">The culture to use in the converter.</param>
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is string)
+            var desiredSize = double.NaN;
+
+            if (parameter != null)
             {
-                var image = new Image
+                try
                 {
-                    Source = new BitmapImage(new Uri(value as string, UriKind.RelativeOrAbsolute), new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore))
-                };
-                return image;
+                    desiredSize = System.Convert.ToDouble(parameter);
+                }
+                catch (Exception ex)
+                {
+                    Debug.WriteLine(ex);
+                }
+            }
+
+            var imagePath = value as string;
+            if (imagePath != null)
+            {
+                return CreateImage(imagePath, desiredSize);
             }
 
             var imageSource = value as ImageSource;
 
-            if (imageSource != null)
+            if (imageSource == null)
             {
-                var image = new Image
-                {
-                    Source = imageSource
-                };
-                return image;
+                return value;
             }
-            return value;
+
+            var image = new Image
+            {
+                Source = ExtractImage(imageSource, desiredSize)
+            };
+
+            return image;
         }
 
         /// <summary>
@@ -55,9 +71,89 @@ public object Convert(object value, Type targetType, object parameter, CultureIn
         /// <param name="value">The value that is produced by the binding target.</param><param name="targetType">The type to convert to.</param><param name="parameter">The converter parameter to use.</param><param name="culture">The culture to use in the converter.</param>
         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            throw new NotImplementedException();
+            return Binding.DoNothing;
         }
 
         #endregion
+
+        private static Image CreateImage(string imagePath, double desiredSize)
+        {
+            if (double.IsNaN(desiredSize) == false
+                && imagePath.EndsWith(".ico"))
+            {
+                return new Image
+                    {
+                        Source = ExtractImageFromIcoFile(imagePath, desiredSize)
+                    };
+            }
+
+            return new Image
+                {
+                    Source = new BitmapImage(new Uri(imagePath, UriKind.RelativeOrAbsolute), new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore))
+                };
+        }
+
+        private static ImageSource ExtractImageFromIcoFile(string imagePath, double desiredSize)
+        {
+            var decoder = BitmapDecoder.Create(
+                new Uri("pack://application:,,," + imagePath, UriKind.RelativeOrAbsolute),
+                BitmapCreateOptions.DelayCreation | BitmapCreateOptions.IgnoreImageCache,
+                BitmapCacheOption.None
+                );
+
+            return ExtractImage(decoder, desiredSize);
+        }
+
+        private static ImageSource ExtractImage(ImageSource imageSource, double desiredSize)
+        {
+            if (double.IsNaN(desiredSize))
+            {
+                return imageSource;
+            }
+
+            var bitmapFrame = imageSource as BitmapFrame;
+
+            // We may have some other type of ImageSource
+            // that doesn't have a notion of frames or decoder
+            if (bitmapFrame == null
+                || bitmapFrame.Decoder == null)
+            {
+                return imageSource;
+            }
+
+            return ExtractImage(bitmapFrame.Decoder, desiredSize);
+        }
+
+        private static ImageSource ExtractImage(BitmapDecoder decoder, double desiredSize)
+        {
+            var dpiFactor = 1.0;
+
+            if (Application.Current.MainWindow != null)
+            {
+                // dpi.M11 = dpiX, dpi.M22 = dpiY
+                var presentationSource = PresentationSource.FromVisual(Application.Current.MainWindow);
+
+                if (presentationSource != null)
+                {
+                    if (presentationSource.CompositionTarget != null)
+                    {
+                        var dpi = presentationSource.CompositionTarget.TransformToDevice;
+                        dpiFactor = dpi.M11;
+                    }
+                }
+            }
+
+            var result = decoder.Frames
+                .OrderBy(f => f.Width)
+                .FirstOrDefault(f => f.Width >= desiredSize * dpiFactor);
+
+            // if there is no matching frame, get the largest frame
+            if (ReferenceEquals(result, default(BitmapFrame)))
+            {
+                result = decoder.Frames.OrderBy(f => f.Width).Last();
+            }
+
+            return result;
+        }
     }
 }