1 files changed, 70 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.MacOS/Renderers/ActivityIndicatorRenderer.cs b/Xamarin.Forms.Platform.MacOS/Renderers/ActivityIndicatorRenderer.cs
new file mode 100644
index 00000000..2e179161
--- /dev/null
+++ b/Xamarin.Forms.Platform.MacOS/Renderers/ActivityIndicatorRenderer.cs
@@ -0,0 +1,70 @@
+using System.ComponentModel;
+using System.Drawing;
+using AppKit;
+using CoreImage;
+
+namespace Xamarin.Forms.Platform.MacOS
+{
+	public class ActivityIndicatorRenderer : ViewRenderer<ActivityIndicator, NSProgressIndicator>
+	{
+		static CIColorPolynomial s_currentColorFilter;
+		static NSColor s_currentColor;
+
+		protected override void OnElementChanged(ElementChangedEventArgs<ActivityIndicator> e)
+		{
+			if (e.NewElement != null)
+			{
+				if (Control == null)
+					SetNativeControl(new NSProgressIndicator(RectangleF.Empty) { Style = NSProgressIndicatorStyle.Spinning });
+
+				UpdateColor();
+				UpdateIsRunning();
+			}
+
+			base.OnElementChanged(e);
+		}
+
+		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
+		{
+			base.OnElementPropertyChanged(sender, e);
+
+			if (e.PropertyName == ActivityIndicator.ColorProperty.PropertyName)
+				UpdateColor();
+			else if (e.PropertyName == ActivityIndicator.IsRunningProperty.PropertyName)
+				UpdateIsRunning();
+		}
+
+		void UpdateColor()
+		{
+			var color = Element.Color;
+			if (s_currentColorFilter == null && color.IsDefault)
+				return;
+
+			if (color.IsDefault)
+				Control.ContentFilters = new CIFilter[0];
+
+			var newColor = Element.Color.ToNSColor();
+			if (Equals(s_currentColor, newColor))
+				return;
+
+			s_currentColor = newColor;
+
+			s_currentColorFilter = new CIColorPolynomial
+			{
+				RedCoefficients = new CIVector(s_currentColor.RedComponent),
+				BlueCoefficients = new CIVector(s_currentColor.BlueComponent),
+				GreenCoefficients = new CIVector(s_currentColor.GreenComponent)
+			};
+
+			Control.ContentFilters = new CIFilter[] { s_currentColorFilter };
+		}
+
+		void UpdateIsRunning()
+		{
+			if (Element.IsRunning)
+				Control.StartAnimation(this);
+			else
+				Control.StopAnimation(this);
+		}
+	}
+}
+\ No newline at end of file