From 94ef2cb089cd6ace101caf2e96c7ea96110ec447 Mon Sep 17 00:00:00 2001
From: David Oliver <david.oliver@nventive.com>
Date: Wed, 18 Dec 2019 13:48:33 -0500
Subject: [PATCH 1/2] [Android] Fix WebView clipping issue

Force WebView to always clip its child (namely, the inner native WebView).
---
 .../UITests.Shared/UITests.Shared.projitems   |  7 +++
 .../WebView/WebView_Animated_Opacity.xaml     | 48 +++++++++++++++++++
 .../WebView/WebView_Animated_Opacity.xaml.cs  | 31 ++++++++++++
 .../Xaml/Controls/WebView/WebView.Android.cs  | 35 ++++++++------
 4 files changed, 106 insertions(+), 15 deletions(-)
 create mode 100644 src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
 create mode 100644 src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml.cs

diff --git a/src/SamplesApp/UITests.Shared/UITests.Shared.projitems b/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
index f0fce816af70..42d4395f3a6b 100644
--- a/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
+++ b/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
@@ -1909,6 +1909,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_Animated_Opacity.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_ChromeClient.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -3841,6 +3845,9 @@
       <DependentUpon>UndefinedHeightListView.xaml</DependentUpon>
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebViewViewModel.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_Animated_Opacity.xaml.cs">
+      <DependentUpon>WebView_Animated_Opacity.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\WebView\WebView_NavigateToString2.xaml.cs">
       <DependentUpon>WebView_NavigateToString2.xaml</DependentUpon>
     </Compile>
diff --git a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
new file mode 100644
index 000000000000..cb67e96eb449
--- /dev/null
+++ b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
@@ -0,0 +1,48 @@
+<UserControl
+    x:Class="UITests.Shared.Windows_UI_Xaml_Controls.WebView.WebView_Animated_Opacity"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:UITests.Shared.Windows_UI_Xaml_Controls.WebView"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    d:DesignHeight="300"
+    d:DesignWidth="400">
+
+
+	<Grid Background="Red">
+		<Grid.RowDefinitions>
+			<RowDefinition Height="auto" />
+			<RowDefinition Height="*" />
+		</Grid.RowDefinitions>
+		<Button Content="Some Text !" />
+
+		<ContentControl x:Name="test"
+						Grid.Row="1"
+						Width="100"
+						Height="100">
+			<ContentControl.Template>
+				<ControlTemplate TargetType="ContentControl">
+					<Grid>
+						<VisualStateManager.VisualStateGroups>
+							<VisualStateGroup x:Name="LoadingStates">
+								<VisualState x:Name="Loading">
+									<Storyboard>
+										<DoubleAnimation Storyboard.TargetName="PART_WebView"
+														 Storyboard.TargetProperty="Opacity"
+														 Duration="0:0:0.1"
+														 To="1" />
+									</Storyboard>
+								</VisualState>
+							</VisualStateGroup>
+						</VisualStateManager.VisualStateGroups>
+
+						<!-- Value -->
+						<WebView x:Name="PART_WebView"
+								 Source="https://web.archive.org/web/20181010203846/https://www.bloomberg.com/view/articles/2018-10-09/google-is-big-and-google-was-small" />
+					</Grid>
+				</ControlTemplate>
+			</ContentControl.Template>
+		</ContentControl>
+	</Grid>
+</UserControl>
diff --git a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml.cs b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml.cs
new file mode 100644
index 000000000000..a9acbbbc8625
--- /dev/null
+++ b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Uno.UI.Samples.Controls;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+
+// The User Control item template is documented at https://go.microsoft.com/fwlink/?LinkId=234236
+
+namespace UITests.Shared.Windows_UI_Xaml_Controls.WebView
+{
+	[SampleControlInfo(description: "Opacity is animated on WebView. It shouldn't exceed bounds while page is loading (Android bug #2006)")]
+	public sealed partial class WebView_Animated_Opacity : UserControl
+	{
+		public WebView_Animated_Opacity()
+		{
+			this.InitializeComponent();
+
+			VisualStateManager.GoToState(test, "Loading", true);
+		}
+	}
+}
diff --git a/src/Uno.UI/UI/Xaml/Controls/WebView/WebView.Android.cs b/src/Uno.UI/UI/Xaml/Controls/WebView/WebView.Android.cs
index a55ade7d8890..e92e8b9a1bec 100644
--- a/src/Uno.UI/UI/Xaml/Controls/WebView/WebView.Android.cs
+++ b/src/Uno.UI/UI/Xaml/Controls/WebView/WebView.Android.cs
@@ -22,12 +22,12 @@
 
 namespace Windows.UI.Xaml.Controls
 {
-	public partial class WebView : Control
+	public partial class WebView : Control, ICustomClippingElement
 	{
 		private Android.Webkit.WebView _webView;
-        private bool _wasLoadedFromString;
-		
-        protected override void OnApplyTemplate()
+		private bool _wasLoadedFromString;
+
+		protected override void OnApplyTemplate()
 		{
 			base.OnApplyTemplate();
 
@@ -71,8 +71,8 @@ partial void NavigatePartial(Uri uri)
 				return;
 			}
 
-            _wasLoadedFromString = false;
-            if (uri.Scheme.Equals("local", StringComparison.OrdinalIgnoreCase))
+			_wasLoadedFromString = false;
+			if (uri.Scheme.Equals("local", StringComparison.OrdinalIgnoreCase))
 			{
 				var path = $"file:///android_asset/{uri.PathAndQuery}";
 				_webView.LoadUrl(path);
@@ -121,8 +121,8 @@ partial void NavigateWithHttpRequestMessagePartial(HttpRequestMessage requestMes
 					element => element.Value.JoinBy(", ")
 				);
 
-            _wasLoadedFromString = false;
-            _webView.LoadUrl(uri.AbsoluteUri, headers);
+			_wasLoadedFromString = false;
+			_webView.LoadUrl(uri.AbsoluteUri, headers);
 		}
 
 		partial void NavigateToStringPartial(string text)
@@ -132,8 +132,8 @@ partial void NavigateToStringPartial(string text)
 				return;
 			}
 
-            _wasLoadedFromString = true;
-            _webView.LoadData(text, "text/html; charset=utf-8", "utf-8");
+			_wasLoadedFromString = true;
+			_webView.LoadData(text, "text/html; charset=utf-8", "utf-8");
 		}
 
 		//This should be IAsyncOperation<string> instead of Task<string> but we use an extension method to enable the same signature in Win.
@@ -305,12 +305,12 @@ public override void OnPageFinished(Android.Webkit.WebView view, string url)
 					IsSuccess = _webViewSuccess,
 					WebErrorStatus = _webErrorStatus
 				};
-                if (!_webView._wasLoadedFromString && !string.IsNullOrEmpty(url))
-                {
-                    args.Uri = new Uri(url);
-                }
+				if (!_webView._wasLoadedFromString && !string.IsNullOrEmpty(url))
+				{
+					args.Uri = new Uri(url);
+				}
 
-                _webView.NavigationCompleted?.Invoke(_webView, args);
+				_webView.NavigationCompleted?.Invoke(_webView, args);
 				base.OnPageFinished(view, url);
 			}
 
@@ -442,5 +442,10 @@ private async Task<T> StartActivity<T>(CancellationToken ct) where T : BaseActiv
 				return null;
 			}
 		}
+
+		bool ICustomClippingElement.AllowClippingToLayoutSlot => true;
+
+		// Force clipping, otherwise native WebView may exceed its bounds in some circumstances (eg when Xaml WebView is animated)
+		bool ICustomClippingElement.ForceClippingToLayoutSlot => true;
 	}
 }

From 37e25f3b77647d8030a16581221d3ef07452323a Mon Sep 17 00:00:00 2001
From: David Oliver <david.oliver@nventive.com>
Date: Wed, 18 Dec 2019 13:59:06 -0500
Subject: [PATCH 2/2] React to code review

---
 .../WebView/WebView_Animated_Opacity.xaml     | 21 +++++++++----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
index cb67e96eb449..bb50244cba18 100644
--- a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
+++ b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/WebView/WebView_Animated_Opacity.xaml
@@ -1,18 +1,17 @@
-<UserControl
-    x:Class="UITests.Shared.Windows_UI_Xaml_Controls.WebView.WebView_Animated_Opacity"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:local="using:UITests.Shared.Windows_UI_Xaml_Controls.WebView"
-    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
-    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-    mc:Ignorable="d"
-    d:DesignHeight="300"
-    d:DesignWidth="400">
+<UserControl x:Class="UITests.Shared.Windows_UI_Xaml_Controls.WebView.WebView_Animated_Opacity"
+			 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+			 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+			 xmlns:local="using:UITests.Shared.Windows_UI_Xaml_Controls.WebView"
+			 xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+			 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+			 mc:Ignorable="d"
+			 d:DesignHeight="300"
+			 d:DesignWidth="400">
 
 
 	<Grid Background="Red">
 		<Grid.RowDefinitions>
-			<RowDefinition Height="auto" />
+			<RowDefinition Height="Auto" />
 			<RowDefinition Height="*" />
 		</Grid.RowDefinitions>
 		<Button Content="Some Text !" />