[GH-12429] Fixed extra height on Shell Flyout and fix issues with flyout items not updating layout

Xamarin.Forms.ControlGallery.Android/Xamarin.Forms.ControlGallery.Android.csproj

@@ -395,7 +395,7 @@
   <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
   <ProjectExtensions>
     <VisualStudio>
-      <UserProperties TriggeredFromHotReload="False" XamarinHotReloadUnhandledDeviceExceptionXamarinFormsControlGalleryAndroidHideInfoBar="True" />
+      <UserProperties XamarinHotReloadUnhandledDeviceExceptionXamarinFormsControlGalleryAndroidHideInfoBar="True" TriggeredFromHotReload="False" />
     </VisualStudio>
   </ProjectExtensions>
 </Project>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/HeaderFooterShellFlyout.cs

@@ -129,11 +129,47 @@ protected override void Init()
 				}),
 				AutomationId = "ResizeHeaderFooter"
 			});
+
+			if (Device.RuntimePlatform == Device.iOS)
+			{
+				Items.Add(new MenuItem()
+				{
+					Text = "Zero Margin Header Test",
+					Command = new Command(() =>
+					{
+						FlyoutHeader =
+							new StackLayout()
+							{
+								AutomationId = "ZeroMarginLayout",
+								Margin = 0,
+								Children =
+								{
+								new Label() { Text = "Header View" }
+								}
+							};
+
+						FlyoutHeaderTemplate = null;
+						FlyoutBehavior = FlyoutBehavior.Locked;
+					}),
+					AutomationId = "ZeroMarginHeader"
+				});
+			}
 		}
 
 
 #if UITEST
 
+#if __IOS__
+		[Test]
+		public void FlyoutHeaderWithZeroMarginShouldHaveNoY()
+		{
+			RunningApp.WaitForElement("PageLoaded");
+			this.TapInFlyout("ZeroMarginHeader", makeSureFlyoutStaysOpen: true);
+			var layout = RunningApp.WaitForElement("ZeroMarginLayout")[0].Rect.Y;
+			Assert.AreEqual(0, layout);
+		}
+#endif
+
 		[Test]
 		public void FlyoutTests()
 		{

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue12429.xaml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<controls:TestShell
+    x:Class="Xamarin.Forms.Controls.Issues.Issue12429"
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:controls="clr-namespace:Xamarin.Forms.Controls"
+    xmlns:local="clr-namespace:Xamarin.Forms.Controls.Issues">
+    <FlyoutItem>
+        <Shell.ItemTemplate>
+            <DataTemplate>
+                <StackLayout Orientation="Horizontal" AutomationId="SmallFlyoutItem" Spacing="0" HeightRequest="{Binding BindingContext.SmallFlyoutItem}" BackgroundColor="LightBlue" >
+                    <Label Text="I'm set to specific height: " TextColor="White" />
+                    <Label Text="{Binding BindingContext.SmallFlyoutItem}" TextColor="White" />
+                </StackLayout>
+            </DataTemplate>
+        </Shell.ItemTemplate>
+        <ShellContent>
+            <local:Issue12429Page />
+        </ShellContent>
+    </FlyoutItem>
+    <FlyoutItem>
+        <Shell.ItemTemplate>
+            <DataTemplate>
+                <StackLayout IsVisible="False" BackgroundColor="Black" >
+                    <Label Text="Not Visible" />
+                </StackLayout>
+            </DataTemplate>
+        </Shell.ItemTemplate>
+        <ShellContent>
+            <local:Issue12429Page />
+        </ShellContent>
+    </FlyoutItem>
+    <FlyoutItem>
+        <Shell.ItemTemplate>
+            <DataTemplate>
+                <StackLayout BackgroundColor="Purple">
+                    <Label Text="I'm sized to my layout" />
+                </StackLayout>
+            </DataTemplate>
+        </Shell.ItemTemplate>
+        <ShellContent>
+            <local:Issue12429Page />
+        </ShellContent>
+    </FlyoutItem>
+    <FlyoutItem>
+        <Shell.ItemTemplate>
+            <DataTemplate>
+                <StackLayout AutomationId="ResizeMe" BackgroundColor="LightGray" HeightRequest="120">
+                    <Button AutomationId="ResizeFlyoutItem" Text="Grow Me" Clicked="ResizeFlyoutItem" />
+                    <Button AutomationId="ResizeFlyoutItemDown" Text="Shrink Me" Clicked="ResizeFlyoutItemDown" />
+                </StackLayout>
+            </DataTemplate>
+        </Shell.ItemTemplate>
+        <ShellContent>
+            <local:Issue12429Page />
+        </ShellContent>
+    </FlyoutItem>
+    <FlyoutItem Title="Default Flyout Item. Height is 44 on iOS and UWP. Height is 50 on Android)">
+        <ShellContent>
+            <local:Issue12429Page />
+        </ShellContent>
+    </FlyoutItem>
+</controls:TestShell>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue12429.xaml.cs

@@ -0,0 +1,150 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 12429, "[Bug] Shell flyout items have a minimum height", PlatformAffected.iOS)]
+#if UITEST
+	[NUnit.Framework.Category(UITestCategories.Shell)]
+#endif
+	public partial class Issue12429 : TestShell
+	{
+		public double SmallFlyoutItem { get;  }
+		public double SizeToModifyBy { get;  }
+
+		public Issue12429()
+		{
+			SmallFlyoutItem = 35d;
+			SizeToModifyBy = 20d;
+
+#if APP
+			InitializeComponent();
+
+
+			if (Device.RuntimePlatform == Device.Android)
+				SmallFlyoutItem = SmallFlyoutItem / Device.info.ScalingFactor;
+
+			if (Device.RuntimePlatform == Device.Android)
+				SizeToModifyBy = SizeToModifyBy / Device.info.ScalingFactor;
+#endif
+
+
+			this.BindingContext = this;
+		}
+
+		protected override void Init()
+		{
+		}
+
+		void ResizeFlyoutItem(System.Object sender, System.EventArgs e)
+		{
+			((sender as Element).Parent as VisualElement).HeightRequest += SizeToModifyBy;
+		}
+
+		void ResizeFlyoutItemDown(System.Object sender, System.EventArgs e)
+		{
+			((sender as Element).Parent as VisualElement).HeightRequest -= SizeToModifyBy;
+		}
+
+#if UITEST
+		[Test]
+		public void FlyoutItemSizesToExplicitHeight()
+		{
+			RunningApp.WaitForElement("PageLoaded");
+			this.ShowFlyout();
+			var height = RunningApp.WaitForElement("SmallFlyoutItem")[0].Rect.Height;
+			Assert.That(height, Is.EqualTo(SmallFlyoutItem).Within(1));
+		}
+
+
+		[Test]
+		public void FlyoutItemHeightAndWidthIncreaseAndDecreaseCorrectly()
+		{
+			RunningApp.WaitForElement("PageLoaded");
+			this.ShowFlyout();
+			var initialHeight = RunningApp.WaitForElement("ResizeMe")[0].Rect.Height;
+
+			TapInFlyout("ResizeFlyoutItem", makeSureFlyoutStaysOpen: true);
+			var newHeight = RunningApp.WaitForElement("ResizeMe")[0].Rect.Height;
+			Assert.That(newHeight - initialHeight, Is.EqualTo(SizeToModifyBy).Within(1));
+
+			TapInFlyout("ResizeFlyoutItemDown", makeSureFlyoutStaysOpen: true);
+			newHeight = RunningApp.WaitForElement("ResizeMe")[0].Rect.Height;
+			Assert.That(initialHeight, Is.EqualTo(newHeight).Within(1));
+
+			TapInFlyout("ResizeFlyoutItemDown", makeSureFlyoutStaysOpen: true);
+			newHeight = RunningApp.WaitForElement("ResizeMe")[0].Rect.Height;
+			Assert.That(initialHeight - newHeight, Is.EqualTo(SizeToModifyBy).Within(1));
+
+		}
+#endif
+
+	}
+
+
+	[Preserve(AllMembers = true)]
+	public class Issue12429Page : ContentPage
+	{
+		public Issue12429Page()
+		{
+			Background = SolidColorBrush.White;
+			var label = new Label
+			{
+				Text = "Flyout Item 1: Explicit Height of 35, Flyout Item 2: will grow and shrink when you click the buttons, Flyout Item 3: doesn't exist, and Flyout Item 4: uses the default platform sizes.",
+				VerticalTextAlignment = TextAlignment.Center,
+				TextColor = Color.Black,
+				AutomationId = "PageLoaded"
+			};
+
+			Content = new StackLayout()
+			{
+				Children =
+				{
+					new Label
+					{
+						Text = "Flyout Item 1: Explicit Height of 35.",
+						VerticalTextAlignment = TextAlignment.Center,
+						TextColor = Color.Black,
+						AutomationId = "PageLoaded"
+					},
+					new Label
+					{
+						Text = "Flyout Item 2: Height sizes to the content.",
+						VerticalTextAlignment = TextAlignment.Center,
+						TextColor = Color.Black
+					},
+					new Label
+					{
+						Text = "Flyout Item 3: will grow and shrink when you click the buttons.",
+						VerticalTextAlignment = TextAlignment.Center,
+						TextColor = Color.Black
+					},
+					new Label
+					{
+						Text = "Flyout Item 4: doesn't exist. You should only see 4 Flyout Items",
+						VerticalTextAlignment = TextAlignment.Center,
+						TextColor = Color.Black
+					},
+					new Label
+					{
+						Text = "Flyout Item 5: uses the default height if no templates are used.",
+						VerticalTextAlignment = TextAlignment.Center,
+						TextColor = Color.Black
+					}
+				}
+			};
+		}
+	}
+
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -55,6 +55,10 @@
       <DependentUpon>Issue12344.xaml</DependentUpon>
     </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue12246.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue12429.xaml.cs">
+      <DependentUpon>Issue12429.xaml</DependentUpon>
+      <SubType>Code</SubType>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Issue12652.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12714.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue2447.xaml.cs">
@@ -2566,9 +2570,13 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12429.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue11853.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
   </ItemGroup>
-</Project>
+</Project>

Xamarin.Forms.Core/Shell/BaseShellItem.cs

@@ -394,6 +394,9 @@ internal static DataTemplate CreateDefaultFlyoutItemCell(string textBinding, str
 
 				if (Device.RuntimePlatform == Device.Android)
 					defaultGridClass.Setters.Add(new Setter { Property = Grid.HeightRequestProperty, Value = 50 });
+				else
+					defaultGridClass.Setters.Add(new Setter { Property = Grid.HeightRequestProperty, Value = 44 });
+
 
 				ColumnDefinitionCollection columnDefinitions = new ColumnDefinitionCollection();