Android fastrenderers (#845)

* Obsolete IVisualElementRenderer.ViewGroup in favor of .View

* Fix NRE

* Changing TContainer in PlatformEffect to View

* Fix "View" type

* new VisualElementRenderer

* First attempt at a fast(er) button renderer

* Fast Label Renderer

* Let's try that again. Behold: Label Fast Renderer

* Move FrameRenderer into Fast Renderers

* Fix Disposable on VisualElementRenderer

* Simplify touch and click handlers

* Drop empty if clause

* [Android] Add initial Image fast renderer

* Split accessibility out to a separate helper class; fix tapgesture bug with label

* [Android] Small fixes to VisualElementRenderer

* Move accessiblity stuff to a separate class (which needs a good name)

* Prevent query from looking to parent for fast renderers

* [Android] ImageRenderer refactoring

* Fix elevation/z-index bugs with Button (e.g., 40173)

* Move SetLabeledBy to Accessibilitizer

* Un-break automation IDs for Labels

* Move gesture handling to its own class

* Split gesture and effect management into separate classes

* Remove unneeded packager from LabelRenderer

* LabelRenderer inherits from FormsTextView

* Batch updates to View

* Fix isOnParentRenderer check for non-Android platforms

* [Controls] Update Xamarin.Forms.ControlGallery.iOS.csproj

* [Android,IOS] Small fixes to rebase and use of Internals

* [Android] Ignroe warning for now

* Fast renderers now passing InputTransparent and IsEnabled tests

* Fast and legacy renderers now pass the Enabled and InputTransparent tests

* Change PlatformEffect back, default container to null

* Fix mangled using directives

14 files changed, 75 insertions, 101 deletions

diff --git a/Xamarin.Forms.Platform.Android/Renderers/ButtonRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/ButtonRenderer.cs
index e07a2be5..7bb97945 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ButtonRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ButtonRenderer.cs
@@ -26,6 +26,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		public ButtonRenderer()
 		{
+			System.Diagnostics.Debug.WriteLine("Slow Button!");
 			AutoPackage = false;
 		}
 
diff --git a/Xamarin.Forms.Platform.Android/Renderers/CarouselPageAdapter.cs b/Xamarin.Forms.Platform.Android/Renderers/CarouselPageAdapter.cs
index efee571d..c31e8e69 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/CarouselPageAdapter.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/CarouselPageAdapter.cs
@@ -55,7 +55,7 @@ namespace Xamarin.Forms.Platform.Android
 			Page destroyedPage = holder.Instance.Item2;
 
 			IVisualElementRenderer renderer = Platform.GetRenderer(destroyedPage);
-			renderer.ViewGroup.RemoveFromParent();
+			renderer.View.RemoveFromParent();
 			holder.Instance.Item1.RemoveFromParent();
 		}
 
@@ -90,7 +90,7 @@ namespace Xamarin.Forms.Platform.Android
 				Platform.SetRenderer(child, Platform.CreateRenderer(child));
 
 			IVisualElementRenderer renderer = Platform.GetRenderer(child);
-			renderer.ViewGroup.RemoveFromParent();
+			renderer.View.RemoveFromParent();
 
 			ViewGroup frame = new PageContainer(_context, renderer);
 
@@ -130,7 +130,7 @@ namespace Xamarin.Forms.Platform.Android
 					IVisualElementRenderer childPageRenderer = Platform.GetRenderer(childPage);
 					if (childPageRenderer != null)
 					{
-						childPageRenderer.ViewGroup.RemoveFromParent();
+						childPageRenderer.View.RemoveFromParent();
 						childPageRenderer.Dispose();
 						Platform.SetRenderer(childPage, null);
 					}
diff --git a/Xamarin.Forms.Platform.Android/Renderers/ConditionalFocusLayout.cs b/Xamarin.Forms.Platform.Android/Renderers/ConditionalFocusLayout.cs
index 311db6b8..5b3002ce 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ConditionalFocusLayout.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ConditionalFocusLayout.cs
@@ -30,7 +30,7 @@ namespace Xamarin.Forms.Platform.Android
 				return;
 
 			IVisualElementRenderer renderer = Platform.GetRenderer(viewCell.View);
-			(renderer?.ViewGroup?.GetChildAt(0) as EditText)?.SetOnTouchListener(this);
+			GetEditText(renderer)?.SetOnTouchListener(this);
 
 			foreach (Element descendant in viewCell.View.Descendants())
 			{
@@ -38,8 +38,14 @@ namespace Xamarin.Forms.Platform.Android
 				if (element == null)
 					continue;
 				renderer = Platform.GetRenderer(element);
-				(renderer?.ViewGroup?.GetChildAt(0) as EditText)?.SetOnTouchListener(this);
+				GetEditText(renderer)?.SetOnTouchListener(this);
 			}
 		}
+
+		internal EditText GetEditText(IVisualElementRenderer renderer)
+		{
+			var viewGroup = renderer?.View as ViewGroup;
+			return viewGroup?.GetChildAt(0) as EditText;
+		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Platform.Android/Renderers/FormsImageView.cs b/Xamarin.Forms.Platform.Android/Renderers/FormsImageView.cs
index ae32e16c..dc0bd2fc 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/FormsImageView.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/FormsImageView.cs
@@ -5,7 +5,7 @@ using Android.Widget;
 
 namespace Xamarin.Forms.Platform.Android
 {
-	internal class FormsImageView : ImageView
+	internal class FormsImageView : ImageView, IImageRendererController
 	{
 		bool _skipInvalidate;
 
diff --git a/Xamarin.Forms.Platform.Android/Renderers/FormsTextView.cs b/Xamarin.Forms.Platform.Android/Renderers/FormsTextView.cs
index 1dc25ea9..2b2bcb7a 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/FormsTextView.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/FormsTextView.cs
@@ -6,7 +6,7 @@ using Android.Widget;
 
 namespace Xamarin.Forms.Platform.Android
 {
-	internal class FormsTextView : TextView
+	public class FormsTextView : TextView
 	{
 		bool _skip;
 
diff --git a/Xamarin.Forms.Platform.Android/Renderers/ImageRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/ImageRenderer.cs
index fee05f1b..57937d89 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ImageRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ImageRenderer.cs
@@ -1,14 +1,18 @@
 using System;
 using System.ComponentModel;
-using System.IO;
-using System.Threading.Tasks;
 using Android.Graphics;
 using Android.Views;
 using AImageView = Android.Widget.ImageView;
 using Xamarin.Forms.Internals;
+using static Xamarin.Forms.Platform.Android.ImageViewExtensions;
 
 namespace Xamarin.Forms.Platform.Android
 {
+	internal interface IImageRendererController
+	{
+		void SkipInvalidate();
+	}
+
 	public class ImageRenderer : ViewRenderer<Image, AImageView>
 	{
 		bool _isDisposed;
@@ -16,6 +20,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		public ImageRenderer()
 		{
+            System.Diagnostics.Debug.WriteLine(">>>>> Old Image Renderer");
 			AutoPackage = false;
 		}
 
@@ -45,8 +50,9 @@ namespace Xamarin.Forms.Platform.Android
 			}
 
 			_motionEventHelper.UpdateElement(e.NewElement);
+			
+			Control.UpdateBitmap(e.NewElement, e.OldElement);
 
-			UpdateBitmap(e.OldElement);
 			UpdateAspect();
 		}
 
@@ -55,7 +61,7 @@ namespace Xamarin.Forms.Platform.Android
 			base.OnElementPropertyChanged(sender, e);
 
 			if (e.PropertyName == Image.SourceProperty.PropertyName)
-				UpdateBitmap();
+				Control.UpdateBitmap(Element);
 			else if (e.PropertyName == Image.AspectProperty.PropertyName)
 				UpdateAspect();
 		}
@@ -66,66 +72,12 @@ namespace Xamarin.Forms.Platform.Android
 			Control.SetScaleType(type);
 		}
 
-		async void UpdateBitmap(Image previous = null)
-		{
-			if (Device.IsInvokeRequired)
-				throw new InvalidOperationException("Image Bitmap must not be updated from background thread");
-
-			if (previous != null && Equals(previous.Source, Element.Source))
-				return;
-
-			((IImageController)Element).SetIsLoading(true);
+        public override bool OnTouchEvent(MotionEvent e)
+        {
+            if (base.OnTouchEvent(e))
+                return true;
 
-			var formsImageView = Control as FormsImageView;
-			formsImageView?.SkipInvalidate();
-
-			Control.SetImageResource(global::Android.Resource.Color.Transparent);
-
-			ImageSource source = Element.Source;
-			Bitmap bitmap = null;
-			IImageSourceHandler handler;
-
-			if (source != null && (handler = Internals.Registrar.Registered.GetHandler<IImageSourceHandler>(source.GetType())) != null)
-			{
-				try
-				{
-					bitmap = await handler.LoadImageAsync(source, Context);
-				}
-				catch (TaskCanceledException)
-				{
-				}
-				catch (IOException ex)
-				{
-					Log.Warning("Xamarin.Forms.Platform.Android.ImageRenderer", "Error updating bitmap: {0}", ex);
-				}
-			}
-
-			if (Element == null || !Equals(Element.Source, source))
-			{
-				bitmap?.Dispose();
-				return;
-			}
-
-			if (!_isDisposed)
-			{
-				if (bitmap == null && source is FileImageSource)
-					Control.SetImageResource(ResourceManager.GetDrawableByName(((FileImageSource)source).File));
-				else
-					Control.SetImageBitmap(bitmap);
-
-				bitmap?.Dispose();
-
-				((IImageController)Element).SetIsLoading(false);
-				((IVisualElementController)Element).NativeSizeChanged();
-			}
-		}
-
-		public override bool OnTouchEvent(MotionEvent e)
-		{
-			if (base.OnTouchEvent(e))
-				return true;
-
-			return _motionEventHelper.HandleMotionEvent(Parent);
-		}
-	}
+            return _motionEventHelper.HandleMotionEvent(Parent);
+        }
+    }
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Platform.Android/Renderers/ListViewRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/ListViewRenderer.cs
index a0906915..bd241c1a 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ListViewRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ListViewRenderer.cs
@@ -45,14 +45,14 @@ namespace Xamarin.Forms.Platform.Android
 
 				if (_headerRenderer != null)
 				{
-					_headerRenderer.ViewGroup.RemoveAllViews();
+					(_headerRenderer.View as ViewGroup)?.RemoveAllViews();
 					_headerRenderer.Dispose();
 					_headerRenderer = null;
 				}
 
 				if (_footerRenderer != null)
 				{
-					_footerRenderer.ViewGroup.RemoveAllViews();
+					(_footerRenderer.View as ViewGroup)?.RemoveAllViews();
 					_footerRenderer.Dispose();
 					_footerRenderer = null;
 				}
@@ -352,12 +352,12 @@ namespace Xamarin.Forms.Platform.Android
 				set
 				{
 					if (_child != null)
-						RemoveView(_child.ViewGroup);
+						RemoveView(_child.View);
 
 					_child = value;
 
 					if (value != null)
-						AddView(value.ViewGroup);
+						AddView(value.View);
 				}
 			}
 
@@ -389,7 +389,7 @@ namespace Xamarin.Forms.Platform.Android
 				int widthSpec = MeasureSpecFactory.MakeMeasureSpec((int)ctx.ToPixels(width), MeasureSpecMode.Exactly);
 				int heightSpec = MeasureSpecFactory.MakeMeasureSpec((int)ctx.ToPixels(request.Request.Height), MeasureSpecMode.Exactly);
 
-				_child.ViewGroup.Measure(widthMeasureSpec, heightMeasureSpec);
+				_child.View.Measure(widthMeasureSpec, heightMeasureSpec);
 				SetMeasuredDimension(widthSpec, heightSpec);
 			}
 		}
diff --git a/Xamarin.Forms.Platform.Android/Renderers/MasterDetailContainer.cs b/Xamarin.Forms.Platform.Android/Renderers/MasterDetailContainer.cs
index a7bebf1e..fd028df1 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/MasterDetailContainer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/MasterDetailContainer.cs
@@ -54,12 +54,12 @@ namespace Xamarin.Forms.Platform.Android
 			if (renderer == null)
 				Platform.SetRenderer(childView, renderer = Platform.CreateRenderer(childView));
 
-			if (renderer.ViewGroup.Parent != this)
+			if (renderer.View.Parent != this)
 			{
-				if (renderer.ViewGroup.Parent != null)
-					renderer.ViewGroup.RemoveFromParent();
+				if (renderer.View.Parent != null)
+					renderer.View.RemoveFromParent();
 				SetDefaultBackgroundColor(renderer);
-				AddView(renderer.ViewGroup);
+				AddView(renderer.View);
 				renderer.UpdateLayout();
 			}
 		}
@@ -148,7 +148,7 @@ namespace Xamarin.Forms.Platform.Android
 			if (ChildView.BackgroundColor == Color.Default)
 			{
 				TypedArray colors = Context.Theme.ObtainStyledAttributes(new[] { global::Android.Resource.Attribute.ColorBackground });
-				renderer.ViewGroup.SetBackgroundColor(new global::Android.Graphics.Color(colors.GetColor(0, 0)));
+				renderer.View.SetBackgroundColor(new global::Android.Graphics.Color(colors.GetColor(0, 0)));
 			}
 		}
 	}
diff --git a/Xamarin.Forms.Platform.Android/Renderers/MasterDetailRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/MasterDetailRenderer.cs
index d18781a7..7e744bc7 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/MasterDetailRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/MasterDetailRenderer.cs
@@ -73,6 +73,13 @@ namespace Xamarin.Forms.Platform.Android
 
 		public event EventHandler<VisualElementChangedEventArgs> ElementChanged;
 
+		event EventHandler<PropertyChangedEventArgs> ElementPropertyChanged;
+		event EventHandler<PropertyChangedEventArgs> IVisualElementRenderer.ElementPropertyChanged
+		{
+			add { ElementPropertyChanged += value; }
+			remove { ElementPropertyChanged -= value; }
+		}
+
 		public SizeRequest GetDesiredSize(int widthConstraint, int heightConstraint)
 		{
 			Measure(widthConstraint, heightConstraint);
@@ -142,10 +149,8 @@ namespace Xamarin.Forms.Platform.Android
 				Tracker.UpdateLayout();
 		}
 
-		public ViewGroup ViewGroup
-		{
-			get { return this; }
-		}
+		public ViewGroup ViewGroup => this;
+		AView IVisualElementRenderer.View => this;
 
 		protected override void Dispose(bool disposing)
 		{
@@ -237,6 +242,7 @@ namespace Xamarin.Forms.Platform.Android
 
 		void HandlePropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
+			ElementPropertyChanged?.Invoke(this, e);
 			if (e.PropertyName == "Master")
 				UpdateMaster();
 			else if (e.PropertyName == "Detail")
diff --git a/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs
index bf6540b9..5d678287 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs
@@ -183,13 +183,13 @@ namespace Xamarin.Forms.Platform.Android
 		void RemovePage(Page page)
 		{
 			IVisualElementRenderer rendererToRemove = Platform.GetRenderer(page);
-			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.ViewGroup.Parent;
+			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.View.Parent;
 
 			containerToRemove.RemoveFromParent();
 
 			if (rendererToRemove != null)
 			{
-				rendererToRemove.ViewGroup.RemoveFromParent();
+				rendererToRemove.View.RemoveFromParent();
 				rendererToRemove.Dispose();
 			}
 
@@ -213,8 +213,8 @@ namespace Xamarin.Forms.Platform.Android
 
 			Page pageToRemove = _current;
 			IVisualElementRenderer rendererToRemove = pageToRemove == null ? null : Platform.GetRenderer(pageToRemove);
-			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.ViewGroup.Parent;
-			PageContainer containerToAdd = (PageContainer)rendererToAdd.ViewGroup.Parent ?? new PageContainer(Context, rendererToAdd);
+			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.View.Parent;
+			PageContainer containerToAdd = (PageContainer)rendererToAdd.View.Parent ?? new PageContainer(Context, rendererToAdd);
 
 			containerToAdd.SetWindowBackground();
 
diff --git a/Xamarin.Forms.Platform.Android/Renderers/PageContainer.cs b/Xamarin.Forms.Platform.Android/Renderers/PageContainer.cs
index 06e33e18..a4e77361 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/PageContainer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/PageContainer.cs
@@ -7,7 +7,7 @@ namespace Xamarin.Forms.Platform.Android
 	{
 		public PageContainer(Context context, IVisualElementRenderer child, bool inFragment = false) : base(context)
 		{
-			AddView(child.ViewGroup);
+			AddView(child.View);
 			Child = child;
 			IsInFragment = inFragment;
 		}
@@ -23,8 +23,8 @@ namespace Xamarin.Forms.Platform.Android
 
 		protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
 		{
-			Child.ViewGroup.Measure(widthMeasureSpec, heightMeasureSpec);
-			SetMeasuredDimension(Child.ViewGroup.MeasuredWidth, Child.ViewGroup.MeasuredHeight);
+			Child.View.Measure(widthMeasureSpec, heightMeasureSpec);
+			SetMeasuredDimension(Child.View.MeasuredWidth, Child.View.MeasuredHeight);
 		}
 	}
 }
\ No newline at end of file
diff --git a/Xamarin.Forms.Platform.Android/Renderers/ScrollViewContainer.cs b/Xamarin.Forms.Platform.Android/Renderers/ScrollViewContainer.cs
index c79e6137..c9354ce2 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ScrollViewContainer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ScrollViewContainer.cs
@@ -32,10 +32,10 @@ namespace Xamarin.Forms.Platform.Android
 				if ((renderer = Platform.GetRenderer(_childView)) == null)
 					Platform.SetRenderer(_childView, renderer = Platform.CreateRenderer(_childView));
 
-				if (renderer.ViewGroup.Parent != null)
-					renderer.ViewGroup.RemoveFromParent();
+				if (renderer.View.Parent != null)
+					renderer.View.RemoveFromParent();
 
-				AddView(renderer.ViewGroup);
+				AddView(renderer.View);
 			}
 		}
 
diff --git a/Xamarin.Forms.Platform.Android/Renderers/ScrollViewRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/ScrollViewRenderer.cs
index b7961411..69020de6 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/ScrollViewRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/ScrollViewRenderer.cs
@@ -7,6 +7,7 @@ using Android.Views;
 using Android.Widget;
 using Xamarin.Forms.Internals;
 using AScrollView = Android.Widget.ScrollView;
+using AView = Android.Views.View;
 
 namespace Xamarin.Forms.Platform.Android
 {
@@ -39,6 +40,13 @@ namespace Xamarin.Forms.Platform.Android
 
 		public event EventHandler<VisualElementChangedEventArgs> ElementChanged;
 
+		event EventHandler<PropertyChangedEventArgs> ElementPropertyChanged;
+		event EventHandler<PropertyChangedEventArgs> IVisualElementRenderer.ElementPropertyChanged
+		{
+			add { ElementPropertyChanged += value; }
+			remove { ElementPropertyChanged -= value; }
+		}
+
 		public SizeRequest GetDesiredSize(int widthConstraint, int heightConstraint)
 		{
 			Measure(widthConstraint, heightConstraint);
@@ -90,10 +98,9 @@ namespace Xamarin.Forms.Platform.Android
 				Tracker.UpdateLayout();
 		}
 
-		public ViewGroup ViewGroup
-		{
-			get { return this; }
-		}
+		public ViewGroup ViewGroup => this;
+
+		AView IVisualElementRenderer.View => this;
 
 		public override void Draw(Canvas canvas)
 		{
@@ -239,6 +246,8 @@ namespace Xamarin.Forms.Platform.Android
 
 		void HandlePropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
+			ElementPropertyChanged?.Invoke(this, e);
+
 			if (e.PropertyName == "Content")
 				LoadContent();
 			else if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName)
diff --git a/Xamarin.Forms.Platform.Android/Renderers/TabbedRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/TabbedRenderer.cs
index f2878a80..2d5f3b02 100644
--- a/Xamarin.Forms.Platform.Android/Renderers/TabbedRenderer.cs
+++ b/Xamarin.Forms.Platform.Android/Renderers/TabbedRenderer.cs
@@ -71,7 +71,7 @@ namespace Xamarin.Forms.Platform.Android
 			if (Platform.GetRenderer(view) == null)
 				Platform.SetRenderer(view, Platform.CreateRenderer(view));
 
-			AddView(Platform.GetRenderer(view).ViewGroup);
+			AddView(Platform.GetRenderer(view).View);
 		}
 	}
 }
\ No newline at end of file