[iOS] Platform specifics to control ScrollView content touch delay (#563)

* can delay content touches optionally

* revert bug fix

* add back _tapGesture

* remove extra declaration

6 files changed, 197 insertions, 3 deletions

diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla41778.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla41778.cs
new file mode 100644
index 00000000..327bea07
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla41778.cs
@@ -0,0 +1,39 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 41778, "Slider Inside ScrollView Will Open MasterDetailPage.Master", PlatformAffected.iOS)]
+	public class Bugzilla41778 : TestMasterDetailPage // or TestMasterDetailPage, etc ...
+	{
+		protected override void Init()
+		{
+			Master = new ContentPage
+			{
+				Title = "Menu",
+				BackgroundColor = Color.Blue
+			};
+
+			Detail = new DetailPageCS();
+		}
+	}
+
+	public class DetailPageCS : ContentPage
+	{
+		public DetailPageCS()
+		{
+			var scrollView = new ScrollView { Content = new Slider() };
+			scrollView.On<iOS>().SetShouldDelayContentTouches(false);
+
+			Content = scrollView;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
index bf393aec..98753ff5 100644
--- a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems
@@ -131,6 +131,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41415.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41418.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41424.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41778.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41600.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla41619.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Bugzilla42000.cs" />
diff --git a/Xamarin.Forms.Core/PlatformConfiguration/iOSSpecific/ScrollView.cs b/Xamarin.Forms.Core/PlatformConfiguration/iOSSpecific/ScrollView.cs
new file mode 100644
index 00000000..1a90a1f1
--- /dev/null
+++ b/Xamarin.Forms.Core/PlatformConfiguration/iOSSpecific/ScrollView.cs
@@ -0,0 +1,30 @@
+namespace Xamarin.Forms.PlatformConfiguration.iOSSpecific
+{
+	using FormsElement = Forms.ScrollView;
+
+	public static class ScrollView
+	{
+		public static readonly BindableProperty ShouldDelayContentTouchesProperty = BindableProperty.Create(nameof(ShouldDelayContentTouches), typeof(bool), typeof(ScrollView), true);
+
+		public static bool GetShouldDelayContentTouches(BindableObject element)
+		{
+			return (bool)element.GetValue(ShouldDelayContentTouchesProperty);
+		}
+
+		public static void SetShouldDelayContentTouches(BindableObject element, bool value)
+		{
+			element.SetValue(ShouldDelayContentTouchesProperty, value);
+		}
+
+		public static bool ShouldDelayContentTouches(this IPlatformElementConfiguration<iOS, FormsElement> config)
+		{
+			return GetShouldDelayContentTouches(config.Element);
+		}
+
+		public static IPlatformElementConfiguration<iOS, FormsElement> SetShouldDelayContentTouches(this IPlatformElementConfiguration<iOS, FormsElement> config, bool value)
+		{
+			SetShouldDelayContentTouches(config.Element, value);
+			return config;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Core/Xamarin.Forms.Core.csproj b/Xamarin.Forms.Core/Xamarin.Forms.Core.csproj
index a052352e..1184e012 100644
--- a/Xamarin.Forms.Core/Xamarin.Forms.Core.csproj
+++ b/Xamarin.Forms.Core/Xamarin.Forms.Core.csproj
@@ -102,6 +102,7 @@
     <Compile Include="PlatformConfiguration\iOSSpecific\BlurEffectStyle.cs" />
     <Compile Include="PlatformConfiguration\iOSSpecific\Entry.cs" />
     <Compile Include="PlatformConfiguration\iOSSpecific\NavigationPage.cs" />
+    <Compile Include="PlatformConfiguration\iOSSpecific\ScrollView.cs" />
     <Compile Include="PlatformConfiguration\iOSSpecific\Picker.cs" />
     <Compile Include="PlatformConfiguration\iOSSpecific\StatusBarTextColorMode.cs" />
     <Compile Include="PlatformConfiguration\iOSSpecific\Page.cs" />
diff --git a/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs b/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs
index 244edfaf..1fe2edbd 100644
--- a/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs
+++ b/Xamarin.Forms.Platform.iOS/Renderers/ScrollViewRenderer.cs
@@ -2,6 +2,7 @@ using System;
 using System.ComponentModel;
 using Xamarin.Forms.Internals;
 using UIKit;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
 using PointF = CoreGraphics.CGPoint;
 using RectangleF = CoreGraphics.CGRect;
 
@@ -66,8 +67,6 @@ namespace Xamarin.Forms.Platform.iOS
 				((IScrollViewController)element).ScrollToRequested += OnScrollToRequested;
 				if (_packager == null)
 				{
-					DelaysContentTouches = true;
-
 					_packager = new VisualElementPackager(this);
 					_packager.Load();
 
@@ -84,6 +83,7 @@ namespace Xamarin.Forms.Platform.iOS
 					});
 				}
 
+				UpdateDelaysContentTouches();
 				UpdateContentSize();
 				UpdateBackgroundColor();
 
@@ -165,7 +165,9 @@ namespace Xamarin.Forms.Platform.iOS
 
 		void HandlePropertyChanged(object sender, PropertyChangedEventArgs e)
 		{
-			if (e.PropertyName == ScrollView.ContentSizeProperty.PropertyName)
+			if (e.PropertyName == PlatformConfiguration.iOSSpecific.ScrollView.ShouldDelayContentTouchesProperty.PropertyName)
+				UpdateDelaysContentTouches();
+			else if (e.PropertyName == ScrollView.ContentSizeProperty.PropertyName)
 				UpdateContentSize();
 			else if (e.PropertyName == VisualElement.BackgroundColorProperty.PropertyName)
 				UpdateBackgroundColor();
@@ -220,6 +222,11 @@ namespace Xamarin.Forms.Platform.iOS
 				Controller.SendScrollFinished();
 		}
 
+		void UpdateDelaysContentTouches()
+		{
+			DelaysContentTouches = ((ScrollView)Element).OnThisPlatform().ShouldDelayContentTouches();
+		}
+
 		void UpdateBackgroundColor()
 		{
 			BackgroundColor = Element.BackgroundColor.ToUIColor(Color.Transparent);
diff --git a/docs/Xamarin.Forms.Core/Xamarin.Forms.PlatformConfiguration.iOSSpecific/ScrollView.xml b/docs/Xamarin.Forms.Core/Xamarin.Forms.PlatformConfiguration.iOSSpecific/ScrollView.xml
new file mode 100644
index 00000000..0e072e10
--- /dev/null
+++ b/docs/Xamarin.Forms.Core/Xamarin.Forms.PlatformConfiguration.iOSSpecific/ScrollView.xml
@@ -0,0 +1,116 @@
+<Type Name="ScrollView" FullName="Xamarin.Forms.PlatformConfiguration.iOSSpecific.ScrollView">
+  <TypeSignature Language="C#" Value="public static class ScrollView" />
+  <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract sealed beforefieldinit ScrollView extends System.Object" />
+  <AssemblyInfo>
+    <AssemblyName>Xamarin.Forms.Core</AssemblyName>
+    <AssemblyVersion>2.0.0.0</AssemblyVersion>
+  </AssemblyInfo>
+  <Base>
+    <BaseTypeName>System.Object</BaseTypeName>
+  </Base>
+  <Interfaces />
+  <Docs>
+    <summary>To be added.</summary>
+    <remarks>To be added.</remarks>
+  </Docs>
+  <Members>
+    <Member MemberName="GetShouldDelayContentTouches">
+      <MemberSignature Language="C#" Value="public static bool GetShouldDelayContentTouches (Xamarin.Forms.BindableObject element);" />
+      <MemberSignature Language="ILAsm" Value=".method public static hidebysig bool GetShouldDelayContentTouches(class Xamarin.Forms.BindableObject element) cil managed" />
+      <MemberType>Method</MemberType>
+      <AssemblyInfo>
+        <AssemblyVersion>2.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>System.Boolean</ReturnType>
+      </ReturnValue>
+      <Parameters>
+        <Parameter Name="element" Type="Xamarin.Forms.BindableObject" />
+      </Parameters>
+      <Docs>
+        <param name="element">To be added.</param>
+        <summary>To be added.</summary>
+        <returns>To be added.</returns>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="ShouldDelayContentTouches">
+      <MemberSignature Language="C#" Value="public static bool ShouldDelayContentTouches (this Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt; config);" />
+      <MemberSignature Language="ILAsm" Value=".method public static hidebysig bool ShouldDelayContentTouches(class Xamarin.Forms.IPlatformElementConfiguration`2&lt;class Xamarin.Forms.PlatformConfiguration.iOS, class Xamarin.Forms.ScrollView&gt; config) cil managed" />
+      <MemberType>Method</MemberType>
+      <AssemblyInfo>
+        <AssemblyVersion>2.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>System.Boolean</ReturnType>
+      </ReturnValue>
+      <Parameters>
+        <Parameter Name="config" Type="Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt;" RefType="this" />
+      </Parameters>
+      <Docs>
+        <param name="config">To be added.</param>
+        <summary>To be added.</summary>
+        <returns>To be added.</returns>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="ShouldDelayContentTouchesProperty">
+      <MemberSignature Language="C#" Value="public static readonly Xamarin.Forms.BindableProperty ShouldDelayContentTouchesProperty;" />
+      <MemberSignature Language="ILAsm" Value=".field public static initonly class Xamarin.Forms.BindableProperty ShouldDelayContentTouchesProperty" />
+      <MemberType>Field</MemberType>
+      <AssemblyInfo>
+        <AssemblyVersion>2.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>Xamarin.Forms.BindableProperty</ReturnType>
+      </ReturnValue>
+      <Docs>
+        <summary>To be added.</summary>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="SetShouldDelayContentTouches">
+      <MemberSignature Language="C#" Value="public static void SetShouldDelayContentTouches (Xamarin.Forms.BindableObject element, bool value);" />
+      <MemberSignature Language="ILAsm" Value=".method public static hidebysig void SetShouldDelayContentTouches(class Xamarin.Forms.BindableObject element, bool value) cil managed" />
+      <MemberType>Method</MemberType>
+      <AssemblyInfo>
+        <AssemblyVersion>2.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>System.Void</ReturnType>
+      </ReturnValue>
+      <Parameters>
+        <Parameter Name="element" Type="Xamarin.Forms.BindableObject" />
+        <Parameter Name="value" Type="System.Boolean" />
+      </Parameters>
+      <Docs>
+        <param name="element">To be added.</param>
+        <param name="value">To be added.</param>
+        <summary>To be added.</summary>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+    <Member MemberName="SetShouldDelayContentTouches">
+      <MemberSignature Language="C#" Value="public static Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt; SetShouldDelayContentTouches (this Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt; config, bool value);" />
+      <MemberSignature Language="ILAsm" Value=".method public static hidebysig class Xamarin.Forms.IPlatformElementConfiguration`2&lt;class Xamarin.Forms.PlatformConfiguration.iOS, class Xamarin.Forms.ScrollView&gt; SetShouldDelayContentTouches(class Xamarin.Forms.IPlatformElementConfiguration`2&lt;class Xamarin.Forms.PlatformConfiguration.iOS, class Xamarin.Forms.ScrollView&gt; config, bool value) cil managed" />
+      <MemberType>Method</MemberType>
+      <AssemblyInfo>
+        <AssemblyVersion>2.0.0.0</AssemblyVersion>
+      </AssemblyInfo>
+      <ReturnValue>
+        <ReturnType>Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt;</ReturnType>
+      </ReturnValue>
+      <Parameters>
+        <Parameter Name="config" Type="Xamarin.Forms.IPlatformElementConfiguration&lt;Xamarin.Forms.PlatformConfiguration.iOS,Xamarin.Forms.ScrollView&gt;" RefType="this" />
+        <Parameter Name="value" Type="System.Boolean" />
+      </Parameters>
+      <Docs>
+        <param name="config">To be added.</param>
+        <param name="value">To be added.</param>
+        <summary>To be added.</summary>
+        <returns>To be added.</returns>
+        <remarks>To be added.</remarks>
+      </Docs>
+    </Member>
+  </Members>
+</Type>