[C] Allow OnIdiom/OnPlatform to return a Binding

src/Controls/src/Build.Tasks/SetPropertiesVisitor.cs

@@ -1260,7 +1260,7 @@ static bool CanSetValue(FieldReference bpRef, bool attached, INode node, IXmlLin
 			if (varValue.VariableType.IsValueType && bpTypeRef.FullName == "System.Object")
 				return true;
 
-			return varValue.VariableType.InheritsFromOrImplements(context.Cache, bpTypeRef);
+			return varValue.VariableType.InheritsFromOrImplements(context.Cache, bpTypeRef) || varValue.VariableType.FullName == "System.Object";
 		}
 
 		static bool CanGetValue(VariableDefinition parent, FieldReference bpRef, bool attached, IXmlLineInfo iXmlLineInfo, ILContext context, out TypeReference propertyType)
@@ -1302,11 +1302,37 @@ static IEnumerable<Instruction> SetValue(VariableDefinition parent, FieldReferen
 			}
 			else if (elementNode != null)
 			{
+				var @else = Create(OpCodes.Nop);
+				var endif = Create(OpCodes.Nop);
+
+				if(context.Variables[elementNode].VariableType.FullName == "System.Object")
+				{
+					//if(value != null && value.GetType().IsAssignableFrom(typeof(BindingBase)))
+					yield return Create(Ldloc, context.Variables[elementNode]);
+					yield return Create(Brfalse, @else);
+
+					yield return Create(Ldtoken, module.ImportReference(context.Cache, ("Microsoft.Maui.Controls", "Microsoft.Maui.Controls", "BindingBase")));
+					yield return Create(Call, module.ImportMethodReference(context.Cache, ("mscorlib", "System", "Type"), methodName: "GetTypeFromHandle", parameterTypes: new[] { ("mscorlib", "System", "RuntimeTypeHandle") }, isStatic: true));
+					yield return Create(Ldloc, context.Variables[elementNode]);
+					yield return Create(Callvirt, module.ImportMethodReference(context.Cache, ("mscorlib", "System", "Object"), methodName: "GetType",  paramCount: 0));
+					yield return Create(Callvirt, module.ImportMethodReference(context.Cache, ("mscorlib", "System", "Type"), methodName: "IsAssignableFrom", parameterTypes: new[] { ("mscorlib", "System", "Type") }));
+					yield return Create(Brfalse, @else);
+					//then
+					yield return Create(Ldloc, context.Variables[elementNode]);
+					yield return Create(Br, endif);
+					//else
+					yield return @else;
+				}
 				var bpTypeRef = bpRef.GetBindablePropertyType(context.Cache, iXmlLineInfo, module);
 				foreach (var instruction in context.Variables[elementNode].LoadAs(context.Cache, bpTypeRef, module))
 					yield return instruction;
 				if (bpTypeRef.IsValueType)
 					yield return Create(Box, module.ImportReference(bpTypeRef));
+
+				//endif
+				if(context.Variables[elementNode].VariableType.FullName == "System.Object")
+					yield return endif;
+
 			}
 			yield return Create(Callvirt, module.ImportMethodReference(context.Cache,
 																	   bindableObjectType,

src/Controls/src/Build.Tasks/VariableDefinitionExtensions.cs

@@ -6,17 +6,17 @@ namespace Microsoft.Maui.Controls.Build.Tasks
 {
 	static class VariableDefinitionExtensions
 	{
-		public static IEnumerable<Instruction> LoadAs(this VariableDefinition self, XamlCache cache, TypeReference type, ModuleDefinition module)
+		public static IEnumerable<Instruction> LoadAs(this VariableDefinition self, XamlCache cache, TypeReference type, ModuleDefinition module, bool box = true, bool unbox = true)
 		{
 			var implicitOperator = self.VariableType.GetImplicitOperatorTo(cache, type, module);
 
 			yield return Instruction.Create(OpCodes.Ldloc, self);
 
 			if (!self.VariableType.InheritsFromOrImplements(cache, type) && implicitOperator != null)
 				yield return Instruction.Create(OpCodes.Call, module.ImportReference(implicitOperator));
-			else if (self.VariableType.IsValueType && !type.IsValueType)
+			else if (box && self.VariableType.IsValueType && !type.IsValueType)
 				yield return Instruction.Create(OpCodes.Box, module.ImportReference(self.VariableType));
-			else if (!self.VariableType.IsValueType && type.IsValueType)
+			else if (unbox && !self.VariableType.IsValueType && type.IsValueType)
 				yield return Instruction.Create(OpCodes.Unbox_Any, module.ImportReference(type));
 		}
 	}

src/Controls/src/Core/BindableObject.cs

@@ -466,6 +466,11 @@ public void SetValue(BindableProperty property, object value)
 			if (property == null)
 				throw new ArgumentNullException(nameof(property));
 
+			if (value is BindingBase binding && !property.ReturnType.IsAssignableFrom(typeof(BindableProperty))) {
+				SetBinding(property, binding);
+				return;
+			}
+
 			if (property.IsReadOnly)
 			{
 				Application.Current?.FindMauiContext()?.CreateLogger<BindableObject>()?.LogWarning($"Cannot set the BindableProperty \"{property.PropertyName}\" because it is readonly.");

src/Controls/tests/Xaml.UnitTests/Issues/Maui18697.xaml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui18697">
+    <ContentPage.ToolbarItems>
+        <ToolbarItem Text="{OnIdiom Desktop={local:Maui18697Translate ProfileToolBarText}}" />
+    </ContentPage.ToolbarItems>
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui18697.xaml.cs

@@ -0,0 +1,85 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Controls.Shapes;
+using Microsoft.Maui.Devices;
+using Microsoft.Maui.Dispatching;
+
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.UnitTests;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui18697 : ContentPage
+{
+    public Maui18697()
+    {
+        InitializeComponent();
+    }
+
+    public Maui18697(bool useCompiledXaml)
+    {
+        //this stub will be replaced at compile time
+    }
+
+    [TestFixture]
+    class Test
+    {
+        MockDeviceInfo mockDeviceInfo;
+
+        [SetUp]
+        public void Setup()
+        {
+            Application.SetCurrentApplication(new MockApplication());
+            DeviceInfo.SetCurrent(mockDeviceInfo = new MockDeviceInfo());
+            DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+        }
+
+
+        [TearDown] public void TearDown()
+        {
+            AppInfo.SetCurrent(null);
+            DeviceInfo.SetCurrent(null);
+        }
+
+        [Test]
+        public void OnBindingRelease([Values(false, true)] bool useCompiledXaml)
+        {
+            mockDeviceInfo.Idiom = DeviceIdiom.Desktop;
+            var page = new Maui18697(useCompiledXaml);
+            Assert.That(page.ToolbarItems[0].Text, Is.EqualTo("_ProfileToolBarText"));
+
+
+        }
+    }
+}
+
+[ContentProperty(nameof(Name))]
+public class Maui18697TranslateExtension : IMarkupExtension<BindingBase>
+{
+    public string Name { get; set; }
+
+    public BindingBase ProvideValue(IServiceProvider serviceProvider)
+    {
+        return new Binding
+        {
+            Mode = BindingMode.OneWay,
+            Path = $"[{Name}]",
+            Source = new Dictionary<string, string>
+            {
+                { "Hello", "_Hello" },
+                { "ProfileToolBarText", "_ProfileToolBarText" }
+            }
+        };
+    }
+
+    object IMarkupExtension.ProvideValue(IServiceProvider serviceProvider)
+    {
+        return ProvideValue(serviceProvider);
+    }
+}

src/Controls/tests/Xaml.UnitTests/Issues/Maui19388.xaml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui19388">
+    <Label Text="Hi"
+        x:Name="label0"
+        BackgroundColor="{OnPlatform Android={AppThemeBinding Light=Red, Dark=Blue}, Default=Green}" />
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui19388.xaml.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Controls.Shapes;
+using Microsoft.Maui.Devices;
+using Microsoft.Maui.Dispatching;
+
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.UnitTests;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui19388 : ContentPage
+{
+    public Maui19388()
+    {
+        InitializeComponent();
+    }
+
+    public Maui19388(bool useCompiledXaml)
+    {
+        //this stub will be replaced at compile time
+    }
+
+    [TestFixture]
+    class Test
+    {
+        MockDeviceInfo mockDeviceInfo;
+
+        [SetUp]
+        public void Setup()
+        {
+            Application.SetCurrentApplication(new MockApplication());
+            DeviceInfo.SetCurrent(mockDeviceInfo = new MockDeviceInfo());
+            DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+        }
+
+
+        [TearDown] public void TearDown()
+        {
+            AppInfo.SetCurrent(null);
+            DeviceInfo.SetCurrent(null);
+        }
+
+        [Test]
+        public void OnPlatformAppThemeBindingRelease([Values(false, true)] bool useCompiledXaml)
+        {
+            Application.Current.UserAppTheme = AppTheme.Light;
+            mockDeviceInfo.Platform = DevicePlatform.iOS;
+            var page = new Maui19388(useCompiledXaml);
+            Assert.That(page.label0.BackgroundColor, Is.EqualTo(Colors.Green));
+
+            mockDeviceInfo.Platform = DevicePlatform.Android;
+            page = new Maui19388(useCompiledXaml);
+            Assert.That(page.label0.BackgroundColor, Is.EqualTo(Colors.Red));
+
+
+        }
+    }
+}

src/Controls/tests/Xaml.UnitTests/Issues/Maui22877.xaml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui22877">
+    <Label x:Name="label0" Text="{OnIdiom {Binding BoundString}, Phone=Grade}" />
+</ContentPage>

src/Controls/tests/Xaml.UnitTests/Issues/Maui22877.xaml.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using Microsoft.Maui.ApplicationModel;
+using Microsoft.Maui.Controls.Core.UnitTests;
+using Microsoft.Maui.Controls.Shapes;
+using Microsoft.Maui.Devices;
+using Microsoft.Maui.Dispatching;
+
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.UnitTests;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.Xaml.UnitTests;
+
+public partial class Maui22877 : ContentPage
+{
+    public Maui22877()
+    {
+        InitializeComponent();
+    }
+
+    public Maui22877(bool useCompiledXaml)
+    {
+        //this stub will be replaced at compile time
+    }
+
+    [TestFixture]
+    class Test
+    {
+        MockDeviceInfo mockDeviceInfo;
+
+        [SetUp]
+        public void Setup()
+        {
+            Application.SetCurrentApplication(new MockApplication());
+            DeviceInfo.SetCurrent(mockDeviceInfo = new MockDeviceInfo());
+            DispatcherProvider.SetCurrent(new DispatcherProviderStub());
+        }
+
+
+        [TearDown] public void TearDown()
+        {
+            AppInfo.SetCurrent(null);
+            DeviceInfo.SetCurrent(null);
+        }
+
+        [Test]
+        public void OnBindingRelease([Values(false, true)] bool useCompiledXaml)
+        {
+            mockDeviceInfo.Idiom = DeviceIdiom.Phone;
+            var page = new Maui22877(useCompiledXaml) {BindingContext = new {BoundString = "BoundString"}};
+            Assert.That(page.label0.Text, Is.EqualTo("Grade"));
+
+            mockDeviceInfo.Idiom = DeviceIdiom.Desktop;
+            page = new Maui22877(useCompiledXaml) {BindingContext = new {BoundString = "BoundString"}};
+            Assert.That(page.label0.Text, Is.EqualTo("BoundString"));
+
+
+        }
+    }
+}

src/Controls/tests/Xaml.UnitTests/Issues/Maui24500.xaml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:Microsoft.Maui.Controls.Xaml.UnitTests"
+             x:Class="Microsoft.Maui.Controls.Xaml.UnitTests.Maui24500">
+    <Label x:Name="label0" IsVisible="{OnIdiom Default={Binding EditingMode}, Phone=False}" />
+</ContentPage>