Simplify WUX feature switch property

nuget/Microsoft.Windows.CsWinRT.Authoring.targets

@@ -33,7 +33,7 @@ Copyright (C) Microsoft Corporation. All rights reserved.
     <CompilerVisibleProperty Include="CsWinRTWindowsMetadata" />
     <CompilerVisibleProperty Include="CsWinRTGenerateProjection" />
     <CompilerVisibleProperty Include="CsWinRTAuthoringInputs" />
-    <CompilerVisibleProperty Include="CsWinRTUIXamlProjections" />
+    <CompilerVisibleProperty Include="CsWinRTUseWindowsUIXamlProjections" />
   </ItemGroup>
 
   <!-- Note this runs before the msbuild editor config file is generated because that is what is used to pass properties to the source generator. -->

nuget/Microsoft.Windows.CsWinRT.targets

@@ -326,6 +326,7 @@ $(CsWinRTInternalProjection)
     <CsWinRTEnableICustomPropertyProviderSupport Condition="'$(CsWinRTEnableICustomPropertyProviderSupport)' == ''">true</CsWinRTEnableICustomPropertyProviderSupport>
     <CsWinRTEnableIReferenceSupport Condition="'$(CsWinRTEnableIReferenceSupport)' == ''">true</CsWinRTEnableIReferenceSupport>
     <CsWinRTEnableIDynamicInterfaceCastableSupport Condition="'$(CsWinRTEnableIDynamicInterfaceCastableSupport)' == ''">true</CsWinRTEnableIDynamicInterfaceCastableSupport>
+    <CsWinRTUseWindowsUIXamlProjections Condition="'$(CsWinRTUseWindowsUIXamlProjections)' == ''">false</CsWinRTUseWindowsUIXamlProjections>
   </PropertyGroup>
 
   <!-- Default values for all other CsWinRT properties (without feature switches) -->
@@ -369,15 +370,10 @@ $(CsWinRTInternalProjection)
                                     Value="$(CsWinRTEnableIDynamicInterfaceCastableSupport)"
                                     Trim="true" />
 
-    <!-- CSWINRT_USE_WINDOWS_UI_XAML_PROJECTIONS switch-->
-    <RuntimeHostConfigurationOption Include="CSWINRT_USE_WINDOWS_UI_XAML_PROJECTIONS" Condition="'$(CsWinRTUIXamlProjections)' == 'WindowsUIXaml'">
-      <Value>true</Value>
-      <Trim>true</Trim>
-    </RuntimeHostConfigurationOption>
-    <RuntimeHostConfigurationOption Include="CSWINRT_USE_WINDOWS_UI_XAML_PROJECTIONS" Condition="'$(CsWinRTUIXamlProjections)' != 'WindowsUIXaml'">
-      <Value>false</Value>
-      <Trim>true</Trim>
-    </RuntimeHostConfigurationOption>
+    <!-- CSWINRT_USE_WINDOWS_UI_XAML_PROJECTIONS switch -->
+    <RuntimeHostConfigurationOption Include="CSWINRT_USE_WINDOWS_UI_XAML_PROJECTIONS"
+                                    Value="$(CsWinRTUseWindowsUIXamlProjections)"
+                                    Trim="true" />
   </ItemGroup>
 
 </Project>

src/Authoring/WinRT.SourceGenerator/AotOptimizer.cs

@@ -22,7 +22,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             var properties = context.AnalyzerConfigOptionsProvider.Select(static (provider, _) => 
                 (provider.IsCsWinRTAotOptimizerEnabled(), provider.IsCsWinRTComponent(), provider.IsCsWinRTCcwLookupTableGeneratorEnabled()));
 
-            var typeMapper = context.AnalyzerConfigOptionsProvider.Select((options, ct) => options.GlobalOptions.GetUIXamlProjectionsMode()).Select((mode, ct) => new TypeMapper(mode));
+            var typeMapper = context.AnalyzerConfigOptionsProvider.Select((options, ct) => options.GetCsWinRTUseWindowsUIXamlProjections()).Select((mode, ct) => new TypeMapper(mode));
 
             var vtablesToAddFromClassTypes = context.SyntaxProvider.CreateSyntaxProvider(
                     static (n, _) => NeedVtableAttribute(n),

src/Authoring/WinRT.SourceGenerator/DiagnosticUtils.cs

@@ -16,7 +16,7 @@ public WinRTComponentScanner(GeneratorExecutionContext context, string assemblyN
             _assemblyName = assemblyName;
             _context = context;
             _flag = false;
-            _typeMapper = new TypeMapper(context.AnalyzerConfigOptions.GlobalOptions.GetUIXamlProjectionsMode());
+            _typeMapper = new TypeMapper(context.AnalyzerConfigOptions.GetCsWinRTUseWindowsUIXamlProjections());
         }
 
         private readonly string _assemblyName;

src/Authoring/WinRT.SourceGenerator/Generator.cs

@@ -28,7 +28,7 @@ public ComponentGenerator(GeneratorExecutionContext context)
         {
             this.context = context;
             Logger = new Logger(context);
-            mapper = new(context.AnalyzerConfigOptions.GlobalOptions.GetUIXamlProjectionsMode());
+            mapper = new(context.AnalyzerConfigOptions.GetCsWinRTUseWindowsUIXamlProjections());
             // TODO-WuxMux: output a module initializer that validates the MUX/WUX projection mode to ensure that things don't get out of sync.
         }
 

src/Authoring/WinRT.SourceGenerator/Helper.cs

@@ -153,6 +153,16 @@ public static bool IsCsWinRTCcwLookupTableGeneratorEnabled(this AnalyzerConfigOp
             return false;
         }
 
+        public static bool GetCsWinRTUseWindowsUIXamlProjections(this AnalyzerConfigOptionsProvider provider)
+        {
+            if (provider.GlobalOptions.TryGetValue("build_property.CsWinRTUseWindowsUIXamlProjections", out var csWinRTUseWindowsUIXamlProjections))
+            {
+                return bool.TryParse(csWinRTUseWindowsUIXamlProjections, out var isCsWinRTUseWindowsUIXamlProjectionsEnabled) && isCsWinRTUseWindowsUIXamlProjectionsEnabled;
+            }
+
+            return false;
+        }
+
         public static int GetCsWinRTAotWarningLevel(this AnalyzerConfigOptionsProvider provider)
         {
             if (provider.GlobalOptions.TryGetValue("build_property.CsWinRTAotWarningLevel", out var csWinRTAotWarningLevelStr) &&

src/Authoring/WinRT.SourceGenerator/TypeMapper.cs

@@ -22,10 +22,10 @@ private static (string, string, string, bool, bool) GetSystemTypeCustomMapping(I
                 ("Windows.UI.Xaml.Interop", "TypeName", "Windows.Foundation.UniversalApiContract", false, true);
         }
 
-        public TypeMapper(UIXamlProjectionsMode xamlMode)
+        public TypeMapper(bool useWindowsUIXamlProjections)
         {
             // This should be in sync with the reverse mapping from WinRT.Runtime/Projections.cs and cswinrt/helpers.h.
-            if (xamlMode == UIXamlProjectionsMode.WindowsUIXaml)
+            if (useWindowsUIXamlProjections)
             {
                 typeMapping = new(StringComparer.Ordinal)
                 {

src/Authoring/WinRT.SourceGenerator/WinRTAotCodeFixer.cs

@@ -42,7 +42,7 @@ public override void Initialize(AnalysisContext context)
                     return;
                 }
 
-                var typeMapper = new TypeMapper(context.Options.AnalyzerConfigOptionsProvider.GlobalOptions.GetUIXamlProjectionsMode());
+                var typeMapper = new TypeMapper(context.Options.AnalyzerConfigOptionsProvider.GetCsWinRTUseWindowsUIXamlProjections());
                 var csWinRTAotWarningLevel = context.Options.AnalyzerConfigOptionsProvider.GetCsWinRTAotWarningLevel();
 
                 context.RegisterSymbolAction(context =>

src/Tests/AuthoringWuxTest/AuthoringWuxTest.csproj

@@ -5,7 +5,8 @@
     <Platforms>x64;x86</Platforms>
     <CsWinRTComponent>true</CsWinRTComponent>
     <IsTrimmable>true</IsTrimmable>
-    <CsWinRTUIXamlProjections>WindowsUIXaml</CsWinRTUIXamlProjections>
+    <UseUwp>true</UseUwp>
+    <CsWinRTUseWindowsUIXamlProjections>true</CsWinRTUseWindowsUIXamlProjections>
     <!-- CsWinRTEnableLogging helps to diagnose generation issues -->
     <!-- <CsWinRTEnableLogging>true</CsWinRTEnableLogging> -->
     <!--<CsWinRTKeepGeneratedSources>true</CsWinRTKeepGeneratedSources>-->