[Tizen] CollectionView optimize for TV profile

Xamarin.Forms.Core/PlatformConfiguration/TizenSpecific/ItemsView.cs

@@ -0,0 +1,31 @@
+namespace Xamarin.Forms.PlatformConfiguration.TizenSpecific
+{
+	using FormsElement = Forms.ItemsView;
+
+	public static class ItemsView
+	{
+		public static readonly BindableProperty FocusedItemScrollPositionProperty = BindableProperty.Create("FocusedItemScrollPosition", typeof(ScrollToPosition), typeof(FormsElement), ScrollToPosition.MakeVisible);
+
+
+		public static ScrollToPosition GetFocusedItemScrollPosition(BindableObject element)
+		{
+			return (ScrollToPosition)element.GetValue(FocusedItemScrollPositionProperty);
+		}
+
+		public static void SetFocusedItemScrollPosition(BindableObject element, ScrollToPosition position)
+		{
+			element.SetValue(FocusedItemScrollPositionProperty, position);
+		}
+
+		public static ScrollToPosition GetFocusedItemScrollPosition(this IPlatformElementConfiguration<Tizen, FormsElement> config)
+		{
+			return GetFocusedItemScrollPosition(config.Element);
+		}
+
+		public static IPlatformElementConfiguration<Tizen, FormsElement> SetFocusedItemScrollPosition(this IPlatformElementConfiguration<Tizen, FormsElement> config, ScrollToPosition position)
+		{
+			SetFocusedItemScrollPosition(config.Element, position);
+			return config;
+		}
+	}
+}

Xamarin.Forms.Platform.Tizen/Native/CollectionView/CollectionView.cs

@@ -123,6 +123,8 @@ public ScrollBarVisiblePolicy HorizontalScrollBarVisiblePolicy
 			set => Scroller.HorizontalScrollBarVisiblePolicy = value;
 		}
 
+		public ScrollToPosition FocusedItemScrollPosition { get; set; }
+
 		int ICollectionViewController.Count
 		{
 			get
@@ -304,10 +306,22 @@ ViewHolder ICollectionViewController.RealizeView(int index)
 
 		void OnItemStateChanged(object sender, EventArgs e)
 		{
-			if (sender is ViewHolder holder && holder.Content != null)
+			ViewHolder holder = (ViewHolder)sender;
+			if (holder.Content != null)
 			{
 				Adaptor?.UpdateViewState(holder.Content, holder.State);
 			}
+
+			if (holder.State == ViewHolderState.Focused && FocusedItemScrollPosition != ScrollToPosition.MakeVisible)
+			{
+				Device.BeginInvokeOnMainThread(() =>
+				{
+					if (holder.State == ViewHolderState.Focused && _viewHolderIndexTable.TryGetValue(holder, out int itemIndex))
+					{
+						ScrollTo(itemIndex, FocusedItemScrollPosition, true);
+					}
+				});
+			}
 		}
 
 		void OnRequestItemSelection(object sender, EventArgs e)
@@ -572,10 +586,13 @@ void OnLayout()
 			if (_adaptor != null && _layoutManager != null)
 			{
 				_layoutManager?.SizeAllocated(Geometry.Size);
+
 				_layoutManager?.LayoutItems(ViewPort);
 				_layoutManager?.SetHeader(_headerView, Adaptor.MeasureHeader(AllocatedSize.Width, AllocatedSize.Height));
 				_layoutManager?.SetFooter(_footerView, Adaptor.MeasureFooter(AllocatedSize.Width, AllocatedSize.Height));
-
+				Scroller.ScrollBlock = LayoutManager.IsHorizontal ? ScrollBlock.Vertical : ScrollBlock.Horizontal;
+				Scroller.HorizontalStepSize = _layoutManager.GetScrollBlockSize();
+				Scroller.VerticalStepSize = _layoutManager.GetScrollBlockSize();
 				UpdateSnapPointsType(SnapPointsType);
 			}
 		}

Xamarin.Forms.Platform.Tizen/Native/CollectionView/GridLayoutManager.cs

@@ -401,9 +401,17 @@ public int GetVisibleItemIndex(int x, int y)
 			if (_scrollCanvasSize.Width < x || _scrollCanvasSize.Height < y)
 				return CollectionView.Count - 1;
 
-			int first = (IsHorizontal ? x : y) / (BaseItemSize + ItemSpacing);
-			if (_hasUnevenRows)
+			int first = 0;
+			if (!_hasUnevenRows)
+			{
+				first = Math.Min(Math.Max(0, ((IsHorizontal ? x : y) - ItemStartPoint) / (BaseItemSize + ItemSpacing)), ((CollectionView.Count - 1) / Span));
+			}
+			else
+			{
 				first = _accumulatedItemSizes.FindIndex(current => (IsHorizontal ? x : y) <= current);
+				if (first == -1)
+					first = (CollectionView.Count - 1) / Span;
+			}
 
 			int second = (IsHorizontal ? y : x) / (ColumnSize + ColumnSpacing);
 			if (second == Span)

Xamarin.Forms.Platform.Tizen/Native/CollectionView/ItemTemplateAdaptor.cs

@@ -134,7 +134,7 @@ public override EvasObject GetFooterView(EvasObject parent)
 			{
 				_footerCache.Parent = _itemsView;
 				var renderer = Platform.GetOrCreateRenderer(_footerCache);
-				(renderer as LayoutRenderer).RegisterOnLayoutUpdated();
+				(renderer as LayoutRenderer)?.RegisterOnLayoutUpdated();
 				return renderer.NativeView;
 			}
 			return null;

Xamarin.Forms.Platform.Tizen/Native/CollectionView/LinearLayoutManager.cs

@@ -344,9 +344,16 @@ public int GetVisibleItemIndex(int x, int y)
 				return CollectionView.Count - 1;
 
 			if (!_hasUnevenRows)
-				return coordinate / (BaseItemSize + ItemSpacing);
+			{
+				return Math.Min(Math.Max(0, (coordinate - ItemStartPoint) / (BaseItemSize + ItemSpacing)), CollectionView.Count - 1);
+			}
 			else
-				return _accumulatedItemSizes.FindIndex(current => coordinate <= current);
+			{
+				var index =  _accumulatedItemSizes.FindIndex(current => coordinate <= current);
+				if (index == -1)
+					index = CollectionView.Count - 1;
+				return index;
+			}
 		}
 
 		public int GetScrollBlockSize()

Xamarin.Forms.Platform.Tizen/Native/CollectionView/ViewHolder.cs

@@ -1,8 +1,6 @@
 using System;
 using ElmSharp;
 using EColor = ElmSharp.Color;
-using ERectangle = ElmSharp.Rectangle;
-
 
 namespace Xamarin.Forms.Platform.Tizen.Native
 {
@@ -125,11 +123,12 @@ protected virtual void UpdateState()
 				_isSelected = true;
 			else if (State == ViewHolderState.Normal)
 				_isSelected = false;
+			else if (State == ViewHolderState.Focused)
+				RaiseTop();
 
 			StateUpdated?.Invoke(this, EventArgs.Empty);
 		}
 
-
 		void OnKeyUp(object sender, EvasKeyEventArgs e)
 		{
 			if (e.KeyName == "Enter" && _focusArea.IsFocused)

Xamarin.Forms.Platform.Tizen/Renderers/ItemsViewRenderer.cs

@@ -3,6 +3,8 @@
 
 using Xamarin.Forms.Platform.Tizen.Native;
 
+using Specific = Xamarin.Forms.PlatformConfiguration.TizenSpecific.ItemsView;
+
 namespace Xamarin.Forms.Platform.Tizen
 {
 	public abstract class ItemsViewRenderer<TItemsView, TNative> : ViewRenderer<TItemsView, TNative>
@@ -19,6 +21,7 @@ public ItemsViewRenderer()
 			RegisterPropertyHandler(ItemsView.ItemTemplateProperty, UpdateAdaptor);
 			RegisterPropertyHandler(ItemsView.HorizontalScrollBarVisibilityProperty, UpdateHorizontalScrollBarVisibility);
 			RegisterPropertyHandler(ItemsView.VerticalScrollBarVisibilityProperty, UpdateVerticalScrollBarVisibility);
+			RegisterPropertyHandler(Specific.FocusedItemScrollPositionProperty, UpdateFocusedItemScrollPosition);
 		}
 
 		protected abstract TNative CreateNativeControl(ElmSharp.EvasObject parent);
@@ -176,6 +179,13 @@ protected virtual void UpdateVerticalScrollBarVisibility()
 		{
 			Control.VerticalScrollBarVisiblePolicy = Element.VerticalScrollBarVisibility.ToNative();
 		}
+
+		void UpdateFocusedItemScrollPosition(bool init)
+		{
+			if (init && Specific.GetFocusedItemScrollPosition(Element) == ScrollToPosition.MakeVisible)
+				return;
+			Control.FocusedItemScrollPosition = Specific.GetFocusedItemScrollPosition(Element);
+		}
 	}
 
 	static class ItemsLayoutExtension