Add Source Navigation Support Across XAML, Previewer, and DevTools

packages/Avalonia/AvaloniaBuildTasks.targets

@@ -134,6 +134,8 @@
       <AvaloniaXamlIlVerifyIl Condition="'$(AvaloniaXamlIlVerifyIl)' == ''">false</AvaloniaXamlIlVerifyIl>
       <AvaloniaXamlIlDebuggerLaunch Condition="'$(AvaloniaXamlIlDebuggerLaunch)' == ''">false</AvaloniaXamlIlDebuggerLaunch>
       <AvaloniaXamlVerboseExceptions Condition="'$(AvaloniaXamlVerboseExceptions)' == ''">false</AvaloniaXamlVerboseExceptions>
+      <AvaloniaXamlCreateSourceInfo Condition="'$(AvaloniaXamlCreateSourceInfo)' == '' AND '$(Configuration)' == 'Debug'">true</AvaloniaXamlCreateSourceInfo>
+      <AvaloniaXamlCreateSourceInfo Condition="'$(AvaloniaXamlCreateSourceInfo)' == '' AND '$(Configuration)' != 'Debug'">false</AvaloniaXamlCreateSourceInfo>
     </PropertyGroup>
 
     <ItemGroup>
@@ -162,6 +164,7 @@
       DelaySign="$(DelaySign)"
       SkipXamlCompilation="$(_AvaloniaSkipXamlCompilation)"
       DebuggerLaunch="$(AvaloniaXamlIlDebuggerLaunch)"
+      CreateSourceInfo="$(AvaloniaXamlCreateSourceInfo)"
       DefaultCompileBindings="$(AvaloniaUseCompiledBindingsByDefault)"
       VerboseExceptions="$(AvaloniaXamlVerboseExceptions)"
       AnalyzerConfigFiles="@(EditorConfigFiles)"/>

packages/Avalonia/AvaloniaRules.Project.xml

@@ -31,6 +31,11 @@
                 Description="Allow debug XAML compilation"
                 Category="Debug" />
 
+  <BoolProperty Name="AvaloniaXamlCreateSourceInfo"
+                DisplayName="Generate XAML Source Info"
+                Description="When enabled, the XAML compiler embeds SourceInfo metadata (file path, line, and column) into generated code. This allows tools and debuggers to locate the original .axaml source position of a selected element at runtime or in the designer."
+                Category="Debug" />
+
   <BoolProperty Name="AvaloniaXamlVerboseExceptions"
                 DisplayName="Report verbose internal exceptions with stack traces"
                 Description="Also includes inner exceptions"

src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs

@@ -32,7 +32,7 @@ public bool Execute()
                 ProjectDirectory, VerifyIl, DefaultCompileBindings, outputImportance,
                 new XamlCompilerDiagnosticsFilter(AnalyzerConfigFiles),
                 (SignAssembly && !DelaySign) ? AssemblyOriginatorKeyFile : null,
-                SkipXamlCompilation, DebuggerLaunch, VerboseExceptions);
+                SkipXamlCompilation, DebuggerLaunch, VerboseExceptions, CreateSourceInfo);
 
             if (res.Success && !res.WrittenFile)
             {
@@ -99,6 +99,8 @@ private static void CopyAndTouch(string source, string destination, bool shouldE
 
         public bool DebuggerLaunch { get; set; }
 
+        public bool CreateSourceInfo { get; set; }
+
         public bool VerboseExceptions { get; set; }
 
         public ITaskItem[] AnalyzerConfigFiles { get; set; }

src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs

@@ -52,7 +52,7 @@ internal static CompileResult Compile(IBuildEngine engine,
             string[] references, string projectDirectory,
             bool verifyIl, bool defaultCompileBindings, MessageImportance logImportance,
             XamlCompilerDiagnosticsFilter diagnosticsFilter, string strongNameKey,
-            bool skipXamlCompilation, bool debuggerLaunch, bool verboseExceptions)
+            bool skipXamlCompilation, bool debuggerLaunch, bool verboseExceptions, bool createSourceInfo)
         {
             try
             {
@@ -67,7 +67,7 @@ internal static CompileResult Compile(IBuildEngine engine,
 	                var compileRes = CompileCore(
                         engine, typeSystem, projectDirectory, verifyIl,
                         defaultCompileBindings, logImportance, diagnosticsFilter,
-                        debuggerLaunch, verboseExceptions);
+                        debuggerLaunch, verboseExceptions, createSourceInfo);
 	                if (compileRes == null)
 	                    return new CompileResult(true);
 	                if (compileRes == false)
@@ -107,7 +107,8 @@ internal static CompileResult Compile(IBuildEngine engine,
             MessageImportance logImportance,
             XamlCompilerDiagnosticsFilter diagnosticsFilter,
             bool debuggerLaunch,
-            bool verboseExceptions)
+            bool verboseExceptions,
+            bool createSourceInfo)
         {
             if (debuggerLaunch)
             {
@@ -210,6 +211,7 @@ TypeDefinition AddClass(string name, TypeAttributes extraAttributes = 0)
             {
                 EnableIlVerification = verifyIl,
                 DefaultCompileBindings = defaultCompileBindings,
+                CreateSourceInfo = createSourceInfo,
                 DynamicSetterContainerProvider = new DefaultXamlDynamicSetterContainerProvider(dynamicSettersBuilder)
             };
 
@@ -477,6 +479,30 @@ bool CompileGroup(IResourceGroup group)
                             classTypeDefinition.Fields.Add(designLoaderField);
                             typeSystem.AddCompilerGeneratedAttribute(designLoaderField);
 
+                            // Add [XamlSourceInfoAttribute] to the generated class.
+                            // Used at design time to locate the original .axaml file,
+                            // since the runtime loader substitutes a fake file name.
+                            if (createSourceInfo && document.FileSource.FilePath is { } filePath) 
+                            {
+                                var attrType = typeSystem.FindType("Avalonia.Markup.Xaml.SourceInfo.XamlSourceInfoAttribute");
+                                var attrTypeRef = asm.MainModule.ImportReference(typeSystem.GetTypeReference(attrType));
+
+                                var attrCtorDef = attrTypeRef.Resolve()
+                                    .Methods.First(m => m.IsConstructor
+                                                     && m.Parameters.Count == 1
+                                                     && m.Parameters[0].ParameterType.FullName == "System.String");
+
+                                var attrCtorRef = asm.MainModule.ImportReference(attrCtorDef);
+                                var designFilenameAttribute = new CustomAttribute(attrCtorRef);
+                                designFilenameAttribute.ConstructorArguments.Add(
+                                    new CustomAttributeArgument(
+                                        asm.MainModule.TypeSystem.String,
+                                        filePath
+                                    )
+                                );
+                                classTypeDefinition.CustomAttributes.Add(designFilenameAttribute);
+                            }
+
                             const string TrampolineName = "!XamlIlPopulateTrampoline";
                             var trampolineMethodWithoutSP = new Lazy<MethodDefinition>(() => CreateTrampolineMethod(false));
                             var trampolineMethodWithSP = new Lazy<MethodDefinition>(() => CreateTrampolineMethod(true));

src/Avalonia.DesignerSupport/Avalonia.DesignerSupport.csproj

@@ -14,9 +14,13 @@
   <ItemGroup>
     <EmbeddedResource Include="Remote\HtmlTransport\webapp\build\**\*.gz" />
     <EmbeddedResource Condition="'$(Configuration)' == 'Debug'" Remove="Remote\HtmlTransport\webapp\build\**\*.map.gz" />
+    <Compile Include="..\Avalonia.Diagnostics\Diagnostics\SourceNavigator\RiderFileSelector.cs" Link="DesignerSelection\RiderFileSelector.cs" />
+    <Compile Include="..\Avalonia.Diagnostics\Diagnostics\SourceNavigator\VisualStudioFileSelector.cs" Link="DesignerSelection\VisualStudioFileSelector.cs" />
+    <Compile Include="..\Avalonia.Diagnostics\Diagnostics\SourceNavigator\VsCodeFileSelection.cs" Link="DesignerSelection\VsCodeFileSelection.cs" />
     <ProjectReference Include="..\Markup\Avalonia.Markup.Xaml\Avalonia.Markup.Xaml.csproj" />
     <ProjectReference Include="..\Markup\Avalonia.Markup\Avalonia.Markup.csproj" />
     <ProjectReference Include="..\Avalonia.Base\Avalonia.Base.csproj" />
     <ProjectReference Include="..\Avalonia.Controls\Avalonia.Controls.csproj" />
+    <PackageReference Include="envdte" Version="17.14.40260" />
   </ItemGroup>
 </Project>

src/Avalonia.DesignerSupport/DesignWindowLoader.cs

@@ -6,6 +6,7 @@
 using Avalonia.Controls;
 using Avalonia.Controls.Embedding.Offscreen;
 using Avalonia.Controls.Platform;
+using Avalonia.DesignerSupport.DesignerSelection;
 using Avalonia.Markup.Xaml;
 using Avalonia.Styling;
 
@@ -47,6 +48,7 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                 });
                 var style = loaded as IStyle;
                 var resources = loaded as ResourceDictionary;
+                bool found = true;
                 if (style != null)
                 {
                     var substitute = Design.GetPreviewWith((AvaloniaObject)style);
@@ -56,6 +58,7 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                         control = substitute;
                     }
                     else
+                    {
                         control = new StackPanel
                         {
                             Children =
@@ -67,6 +70,8 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                                 new TextBlock {Text = "before setters in your first Style"}
                             }
                         };
+                        found = false;
+                    }
                 }
                 else if (resources != null)
                 {
@@ -77,6 +82,7 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                         control = substitute;
                     }
                     else
+                    {
                         control = new StackPanel
                         {
                             Children =
@@ -88,9 +94,14 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                                 new TextBlock {Text = "in your resource dictionary"}
                             }
                         };
+                        found = false;
+                    }
                 }
                 else if (loaded is Application)
+                {
                     control = new TextBlock { Text = "This file cannot be previewed in design view" };
+                    found = false;
+                }
                 else
                     control = (Control)loaded;
 
@@ -104,6 +115,10 @@ public static Window LoadDesignerWindow(string xaml, string assemblyPath, string
                     offscreenImpl.RenderScaling = renderScaling;
 
                 Design.ApplyDesignModeProperties(window, control);
+                if (found)
+                {
+                    ElementInspector.Initialize(window);
+                }
 
                 if (!window.IsSet(Window.SizeToContentProperty))
                 {