From 17fdde66d94155fc62a034fa6658995bef6fd6e5 Mon Sep 17 00:00:00 2001
From: Jason Smith <jason.smith@xamarin.com>
Date: Tue, 22 Mar 2016 13:02:25 -0700
Subject: Initial import

---
 Xamarin.Forms.Platform.WinRT/ImageRenderer.cs | 132 ++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 Xamarin.Forms.Platform.WinRT/ImageRenderer.cs

(limited to 'Xamarin.Forms.Platform.WinRT/ImageRenderer.cs')

diff --git a/Xamarin.Forms.Platform.WinRT/ImageRenderer.cs b/Xamarin.Forms.Platform.WinRT/ImageRenderer.cs
new file mode 100644
index 00000000..47c674c7
--- /dev/null
+++ b/Xamarin.Forms.Platform.WinRT/ImageRenderer.cs
@@ -0,0 +1,132 @@
+using System;
+using System.ComponentModel;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Media.Imaging;
+
+#if WINDOWS_UWP
+
+namespace Xamarin.Forms.Platform.UWP
+#else
+
+namespace Xamarin.Forms.Platform.WinRT
+#endif
+{
+	public class ImageRenderer : ViewRenderer<Image, Windows.UI.Xaml.Controls.Image>
+	{
+		bool _measured;
+
+		public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
+		{
+			if (Control.Source == null)
+				return new SizeRequest();
+
+			_measured = true;
+
+			var result = new Size { Width = ((BitmapImage)Control.Source).PixelWidth, Height = ((BitmapImage)Control.Source).PixelHeight };
+
+			return new SizeRequest(result);
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (Control != null)
+			{
+				Control.ImageOpened -= OnImageOpened;
+			}
+
+			base.Dispose(disposing);
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<Image> e)
+		{
+			base.OnElementChanged(e);
+
+			if (e.NewElement != null)
+			{
+				if (Control == null)
+				{
+					var image = new Windows.UI.Xaml.Controls.Image();
+					image.ImageOpened += OnImageOpened;
+					SetNativeControl(image);
+				}
+
+				UpdateSource();
+				UpdateAspect();
+			}
+		}
+
+		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
+		{
+			base.OnElementPropertyChanged(sender, e);
+
+			if (e.PropertyName == Image.SourceProperty.PropertyName)
+				UpdateSource();
+			else if (e.PropertyName == Image.AspectProperty.PropertyName)
+				UpdateAspect();
+		}
+
+		static Stretch GetStretch(Aspect aspect)
+		{
+			switch (aspect)
+			{
+				case Aspect.Fill:
+					return Stretch.Fill;
+				case Aspect.AspectFill:
+					return Stretch.UniformToFill;
+				default:
+				case Aspect.AspectFit:
+					return Stretch.Uniform;
+			}
+		}
+
+		void OnImageOpened(object sender, RoutedEventArgs routedEventArgs)
+		{
+			if (_measured)
+			{
+				RefreshImage();
+			}
+		}
+
+		void RefreshImage()
+		{
+			Element?.InvalidateMeasure(InvalidationTrigger.RendererReady);
+		}
+
+		void UpdateAspect()
+		{
+			Control.Stretch = GetStretch(Element.Aspect);
+		}
+
+		async void UpdateSource()
+		{
+			Element.SetValueCore(Image.IsLoadingPropertyKey, true);
+
+			ImageSource source = Element.Source;
+			IImageSourceHandler handler;
+			if (source != null && (handler = Registrar.Registered.GetHandler<IImageSourceHandler>(source.GetType())) != null)
+			{
+				Windows.UI.Xaml.Media.ImageSource imagesource;
+				try
+				{
+					imagesource = await handler.LoadImageAsync(source);
+				}
+				catch (OperationCanceledException)
+				{
+					imagesource = null;
+				}
+
+				// In the time it takes to await the imagesource, some zippy little app
+				// might have disposed of this Image already.
+				if (Control != null)
+					Control.Source = imagesource;
+
+				RefreshImage();
+			}
+			else
+				Control.Source = null;
+
+			Element?.SetValueCore(Image.IsLoadingPropertyKey, false);
+		}
+	}
+}
\ No newline at end of file
-- 
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