1 files changed, 62 insertions, 0 deletions
diff --git a/Xamarin.Forms.Platform.Android/Renderers/AHorizontalScrollView.cs b/Xamarin.Forms.Platform.Android/Renderers/AHorizontalScrollView.cs
new file mode 100644
index 00000000..6a64a35b
--- /dev/null
+++ b/Xamarin.Forms.Platform.Android/Renderers/AHorizontalScrollView.cs
@@ -0,0 +1,62 @@
+using Android.Content;
+using Android.Views;
+using Android.Widget;
+
+namespace Xamarin.Forms.Platform.Android
+{
+	public class AHorizontalScrollView : HorizontalScrollView
+	{
+		readonly ScrollViewRenderer _renderer;
+
+		public AHorizontalScrollView(Context context, ScrollViewRenderer renderer) : base(context)
+		{
+			_renderer = renderer;
+		}
+
+		internal bool IsBidirectional { get; set; }
+
+		public override bool OnInterceptTouchEvent(MotionEvent ev)
+		{
+			// set the start point for the bidirectional scroll; 
+			// Down is swallowed by other controls, so we'll just sneak this in here without actually preventing
+			// other controls from getting the event.
+			if (IsBidirectional && ev.Action == MotionEventActions.Down)
+			{
+				_renderer.LastY = ev.RawY;
+				_renderer.LastX = ev.RawX;
+			}
+
+			return base.OnInterceptTouchEvent(ev);
+		}
+
+		public override bool OnTouchEvent(MotionEvent ev)
+		{
+			// The nested ScrollViews will allow us to scroll EITHER vertically OR horizontally in a single gesture.
+			// This will allow us to also scroll diagonally.
+			// We'll fall through to the base event so we still get the fling from the ScrollViews.
+			// We have to do this in both ScrollViews, since a single gesture will be owned by one or the other, depending
+			// on the initial direction of movement (i.e., horizontal/vertical).
+			if (IsBidirectional)
+			{
+				float dX = _renderer.LastX - ev.RawX;
+				float dY = _renderer.LastY - ev.RawY;
+				_renderer.LastY = ev.RawY;
+				_renderer.LastX = ev.RawX;
+				if (ev.Action == MotionEventActions.Move)
+				{
+					var parent = (global::Android.Widget.ScrollView)Parent;
+					parent.ScrollBy(0, (int)dY);
+					ScrollBy((int)dX, 0);
+				}
+			}
+			return base.OnTouchEvent(ev);
+		}
+
+		protected override void OnScrollChanged(int l, int t, int oldl, int oldt)
+		{
+			base.OnScrollChanged(l, t, oldl, oldt);
+
+			_renderer.UpdateScrollPosition(Forms.Context.FromPixels(l), Forms.Context.FromPixels(t));
+		}
+	}
+}
+\ No newline at end of file