1 files changed, 69 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.Android/Renderers/CarouselViewExtensions.cs b/Xamarin.Forms.Platform.Android/Renderers/CarouselViewExtensions.cs
new file mode 100644
index 00000000..6349b2b7
--- /dev/null
+++ b/Xamarin.Forms.Platform.Android/Renderers/CarouselViewExtensions.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Diagnostics;
+using System.Linq;
+using Android.Content;
+using Android.Graphics;
+
+namespace Xamarin.Forms.Platform.Android
+{
+	internal static class CarouselViewExtensions
+	{
+		internal static int Area(this System.Drawing.Rectangle rectangle)
+		{
+			return rectangle.Width * rectangle.Height;
+		}
+
+		internal static IntVector BoundTranslation(this System.Drawing.Rectangle viewport, IntVector delta, System.Drawing.Rectangle bound)
+		{
+			// TODO: generalize the math
+			Debug.Assert(delta.X == 0 || delta.Y == 0);
+
+			IntVector start = viewport.LeadingCorner(delta);
+			IntVector end = start + delta;
+			IntVector clampedEnd = end.Clamp(bound);
+			IntVector clampedDelta = clampedEnd - start;
+			return clampedDelta;
+		}
+
+		internal static IntVector Center(this System.Drawing.Rectangle rectangle)
+		{
+			return (IntVector)rectangle.Location + (IntVector)rectangle.Size / 2;
+		}
+
+		internal static IntVector Clamp(this IntVector position, System.Drawing.Rectangle bound)
+		{
+			return new IntVector(position.X.Clamp(bound.Left, bound.Right), position.Y.Clamp(bound.Top, bound.Bottom));
+		}
+
+		internal static IntVector LeadingCorner(this System.Drawing.Rectangle rectangle, IntVector delta)
+		{
+			return new IntVector(delta.X < 0 ? rectangle.Left : rectangle.Right, delta.Y < 0 ? rectangle.Top : rectangle.Bottom);
+		}
+
+		internal static bool LexicographicallyLess(this System.Drawing.Point source, System.Drawing.Point target)
+		{
+			if (source.X < target.X)
+				return true;
+
+			if (source.X > target.X)
+				return false;
+
+			return source.Y < target.Y;
+		}
+
+		internal static Rect ToAndroidRectangle(this System.Drawing.Rectangle rectangle)
+		{
+			return new Rect(rectangle.Left, right: rectangle.Right, top: rectangle.Top, bottom: rectangle.Bottom);
+		}
+
+		internal static Rectangle ToFormsRectangle(this System.Drawing.Rectangle rectangle, Context context)
+		{
+			return new Rectangle(context.FromPixels(rectangle.Left), context.FromPixels(rectangle.Top), context.FromPixels(rectangle.Width), context.FromPixels(rectangle.Height));
+		}
+
+		internal static int[] ToRange(this Tuple<int, int> startAndCount)
+		{
+			return Enumerable.Range(startAndCount.Item1, startAndCount.Item2).ToArray();
+		}
+	}
+}
+\ No newline at end of file