[macOS] Hang App scaling a View to zero

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8981.xaml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<controls:TestContentPage
+    xmlns="http://xamarin.com/schemas/2014/forms"
+    xmlns:controls="clr-namespace:Xamarin.Forms.Controls"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:d="http://xamarin.com/schemas/2014/forms/design"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    x:Class="Xamarin.Forms.Controls.Issues.Issue8981"
+    Title="Issue 8981">
+    <Grid RowDefinitions="Auto,*">
+        <Label
+            Grid.Row="0"
+            AutomationId = "TestReady"
+            Padding="12"
+            BackgroundColor="Black"
+            TextColor="White"
+            Text="Without hang, the test has passed."/>
+        <StackLayout
+            Grid.Row="1">
+            <Label
+                x:Name="TestLabel"
+                Text="#8981" 
+                HorizontalOptions="Center"
+                VerticalOptions="Center" />
+            <Label
+                Text="Scale X:" />
+            <Slider
+                Minimum="-11"
+                Maximum="11"
+                Value="1"
+                ValueChanged="OnScaleXChanged" />
+            <Label
+                Text="Scale Y:" />
+            <Slider
+                Minimum="-11"
+                Maximum="11"
+                Value="1"
+                ValueChanged="OnScaleYChanged" />
+            <Label
+                Text="Scale:" />
+            <Slider
+                Minimum="-11"
+                Maximum="11"
+                Value="1"
+                ValueChanged="OnScaleChanged" />
+        </StackLayout>
+    </Grid>
+</controls:TestContentPage>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue8981.xaml.cs

@@ -0,0 +1,56 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+#if UITEST
+using Xamarin.Forms.Core.UITests;
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.CollectionView)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 8981, "[Bug] [macOS] Hang App scaling a View to zero",
+		PlatformAffected.macOS)]
+	public partial class Issue8981 : TestContentPage
+	{
+		public Issue8981()
+		{
+#if APP
+			InitializeComponent();
+#endif
+		}
+
+		protected override void Init()
+		{
+
+		}
+#if APP
+		protected override async void OnAppearing()
+		{
+			base.OnAppearing();
+
+			await TestLabel.ScaleTo(0, 1000);
+			await TestLabel.ScaleTo(1, 1000);
+		}
+
+		void OnScaleXChanged(object sender, ValueChangedEventArgs e)
+		{
+			TestLabel.ScaleX = e.NewValue;
+		}
+
+		void OnScaleYChanged(object sender, ValueChangedEventArgs e)
+		{
+			TestLabel.ScaleY = e.NewValue;
+		}
+
+		void OnScaleChanged(object sender, ValueChangedEventArgs e)
+		{
+			TestLabel.Scale = e.NewValue;
+		}
+#endif
+	}
+}

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

@@ -1700,6 +1700,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue8988.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12084.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12512.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue8981.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue3311.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12473.xaml.cs">
       <DependentUpon>Issue12473.xaml</DependentUpon>
@@ -2100,8 +2101,11 @@
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12084.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue8981.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12473.xaml">
-      <SubType>Designer</SubType>
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Issue12809.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>

Xamarin.Forms.Platform.iOS/VisualElementTracker.cs

@@ -325,10 +325,22 @@ void update()
 					transform = transform.Rotate(rotationY * (float)Math.PI / 180.0f, 0.0f, 1.0f, 0.0f);
 
 				transform = transform.Rotate(rotation * (float)Math.PI / 180.0f, 0.0f, 0.0f, 1.0f);
+#if !__MOBILE__
+				if (Math.Abs(scaleX - 1) > epsilon || Math.Abs(scaleY - 1) > epsilon)
+				{
+					if (scaleX == 0)
+						scaleX = (float)epsilon;
+					if (scaleY == 0)
+						scaleY = (float)epsilon;
+					if (scale == 0)
+						scale = (float)epsilon;
 
+					transform = transform.Scale(scaleX, scaleY, scale);
+				}
+#else
 				if (Math.Abs(scaleX - 1) > epsilon || Math.Abs(scaleY - 1) > epsilon)
 					transform = transform.Scale(scaleX, scaleY, scale);
-
+#endif
 				if (Foundation.NSThread.IsMain)
 				{
 					caLayer.Transform = transform;