AddUIElement / AddButton infrastructure for inline UI

Assisted-by: Claude:claude-opus-4-7:Claude Code

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy/SmartTextOutputExtensions.cs

@@ -0,0 +1,65 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Layout;
+using Avalonia.Media;
+
+using ILSpy.TextView;
+
+namespace ILSpy
+{
+	public static class SmartTextOutputExtensions
+	{
+		public static void AddButton(this ISmartTextOutput output, IImage? icon, string text, EventHandler<RoutedEventArgs> click)
+		{
+			ArgumentNullException.ThrowIfNull(output);
+			ArgumentNullException.ThrowIfNull(click);
+
+			output.AddUIElement(() => {
+				var button = new Button {
+					Cursor = new Cursor(StandardCursorType.Arrow),
+					Margin = new Thickness(2),
+					Padding = new Thickness(9, 1, 9, 1),
+					MinWidth = 73,
+				};
+				if (icon != null)
+				{
+					button.Content = new StackPanel {
+						Orientation = Orientation.Horizontal,
+						Children = {
+							new Image { Width = 16, Height = 16, Source = icon, Margin = new Thickness(0, 0, 4, 0) },
+							new TextBlock { Text = text },
+						},
+					};
+				}
+				else
+				{
+					button.Content = text;
+				}
+				button.Click += click;
+				return button;
+			});
+		}
+	}
+}

ILSpy/TextView/AvaloniaEditTextOutput.cs

@@ -16,10 +16,13 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+using System;
 using System.Collections.Generic;
 using System.Reflection.Metadata;
 using System.Text;
 
+using Avalonia.Controls;
+
 using AvaloniaEdit.Document;
 using AvaloniaEdit.Folding;
 using AvaloniaEdit.Highlighting;
@@ -62,6 +65,12 @@ namespace ILSpy.TextView
 		/// <summary>Maps reference targets to their definition offsets in the rendered text.</summary>
 		public DefinitionLookup DefinitionLookup { get; } = new();
 
+		readonly List<KeyValuePair<int, Lazy<Control>>> uiElements = new();
+
+		/// <summary>Inline UI elements collected during writing, in offset order. Fed to
+		/// <see cref="UIElementGenerator"/> by the text view.</summary>
+		public IReadOnlyList<KeyValuePair<int, Lazy<Control>>> UIElements => uiElements;
+
 		public string Title { get; set; } = string.Empty;
 
 		public string IndentationString { get; set; } = "\t";
@@ -172,6 +181,15 @@ namespace ILSpy.TextView
 				foldings.Add(folding);
 		}
 
+		public void AddUIElement(Func<Control> element)
+		{
+			if (element == null)
+				return;
+			if (uiElements.Count > 0 && uiElements[uiElements.Count - 1].Key == builder.Length)
+				throw new InvalidOperationException("Only one UIElement is allowed for each position in the document.");
+			uiElements.Add(new KeyValuePair<int, Lazy<Control>>(builder.Length, new Lazy<Control>(element)));
+		}
+
 		public void BeginSpan(HighlightingColor highlightingColor)
 		{
 			openSpans.Push((builder.Length, highlightingColor));

ILSpy/TextView/DecompilerTabPageModel.cs

@@ -21,6 +21,7 @@ using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 
+using Avalonia.Controls;
 using Avalonia.Threading;
 
 using AvaloniaEdit.Document;
@@ -90,6 +91,13 @@ namespace ILSpy.TextView
 		[ObservableProperty]
 		private DefinitionLookup? definitionLookup;
 
+		/// <summary>
+		/// Inline UI elements (<see cref="ISmartTextOutput.AddUIElement"/>), in offset order.
+		/// Fed to <see cref="UIElementGenerator"/> by the text view.
+		/// </summary>
+		[ObservableProperty]
+		private IReadOnlyList<KeyValuePair<int, Lazy<Control>>>? uIElements;
+
 		/// <summary>
 		/// Fired when the user clicks a cross-document reference. The host (DockWorkspace)
 		/// resolves the target on the assembly tree side.
@@ -172,6 +180,7 @@ namespace ILSpy.TextView
 				var collectedFoldings = output.Foldings;
 				var collectedReferences = output.References;
 				var collectedLookup = output.DefinitionLookup;
+				var collectedUIElements = output.UIElements;
 				await Dispatcher.UIThread.InvokeAsync(() => {
 					Title = nodeTitle;
 					SyntaxExtension = newSyntaxExtension;
@@ -179,6 +188,7 @@ namespace ILSpy.TextView
 					Foldings = collectedFoldings;
 					References = collectedReferences;
 					DefinitionLookup = collectedLookup;
+					UIElements = collectedUIElements;
 					Text = rendered;
 				});
 			}

ILSpy/TextView/DecompilerTextView.axaml.cs

@@ -62,6 +62,7 @@ namespace ILSpy.TextView
 		const double MaxMovementAwayFromPopup = 5;
 
 		readonly ReferenceElementGenerator referenceElementGenerator;
+		readonly UIElementGenerator uiElementGenerator;
 		readonly TextMarkerService textMarkerService;
 		readonly List<TextMarker> localReferenceMarks = new();
 		RichTextColorizer? activeColorizer;
@@ -81,6 +82,9 @@ namespace ILSpy.TextView
 			referenceElementGenerator.ReferenceClicked += OnReferenceClicked;
 			Editor.TextArea.TextView.ElementGenerators.Add(referenceElementGenerator);
 
+			uiElementGenerator = new UIElementGenerator();
+			Editor.TextArea.TextView.ElementGenerators.Add(uiElementGenerator);
+
 			// Background renderer that paints local-reference highlights. Lives once for the
 			// lifetime of the view; the marks themselves are cleared and rebuilt per click.
 			textMarkerService = new TextMarkerService(Editor.TextArea.TextView);
@@ -180,6 +184,7 @@ namespace ILSpy.TextView
 			}
 
 			referenceElementGenerator.References = model.References;
+			uiElementGenerator.UIElements = model.UIElements;
 			Editor.TextArea.TextView.Redraw();
 
 			Editor.ScrollToHome();

ILSpy/TextView/ISmartTextOutput.cs

@@ -16,6 +16,10 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+using System;
+
+using Avalonia.Controls;
+
 using AvaloniaEdit.Highlighting;
 
 using ICSharpCode.Decompiler;
@@ -23,11 +27,17 @@ using ICSharpCode.Decompiler;
 namespace ILSpy.TextView
 {
 	/// <summary>
-	/// Adds Avalonia-specific output features to <see cref="ITextOutput"/> — currently just
-	/// span-based highlighting. Inline UI elements are deferred to a later phase.
+	/// Adds Avalonia-specific output features to <see cref="ITextOutput"/>: span-based
+	/// highlighting + inline UI elements rendered by <see cref="UIElementGenerator"/>.
 	/// </summary>
 	public interface ISmartTextOutput : ITextOutput
 	{
+		/// <summary>
+		/// Inserts an interactive UI element at the current position. The factory runs lazily
+		/// on the UI thread when the element generator first realises the row.
+		/// </summary>
+		void AddUIElement(Func<Control> element);
+
 		void BeginSpan(HighlightingColor highlightingColor);
 		void EndSpan();
 

ILSpy/TextView/UIElementGenerator.cs

@@ -0,0 +1,79 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+
+using Avalonia.Controls;
+
+using AvaloniaEdit.Rendering;
+
+namespace ILSpy.TextView
+{
+	using Pair = KeyValuePair<int, Lazy<Control>>;
+
+	/// <summary>
+	/// Embeds inline UI elements produced by <see cref="ISmartTextOutput.AddUIElement"/> in
+	/// the rendered text. Mirrors the WPF host's UIElementGenerator: the element factory is
+	/// stored as a <see cref="Lazy{Control}"/> so the actual control is constructed on the
+	/// UI thread when the row is first realised.
+	/// </summary>
+	sealed class UIElementGenerator : VisualLineElementGenerator, IComparer<Pair>
+	{
+		public IReadOnlyList<Pair>? UIElements;
+
+		public override int GetFirstInterestedOffset(int startOffset)
+		{
+			if (UIElements == null)
+				return -1;
+			int r = BinarySearch(UIElements, new Pair(startOffset, null!));
+			if (r < 0)
+				r = ~r;
+			return r < UIElements.Count ? UIElements[r].Key : -1;
+		}
+
+		public override VisualLineElement? ConstructElement(int offset)
+		{
+			if (UIElements == null)
+				return null;
+			int r = BinarySearch(UIElements, new Pair(offset, null!));
+			return r >= 0 ? new InlineObjectElement(0, UIElements[r].Value.Value) : null;
+		}
+
+		int IComparer<Pair>.Compare(Pair x, Pair y) => x.Key.CompareTo(y.Key);
+
+		// IReadOnlyList has no BinarySearch. Hand-rolled — list is offset-sorted by
+		// AvaloniaEditTextOutput.AddUIElement.
+		int BinarySearch(IReadOnlyList<Pair> list, Pair value)
+		{
+			int lo = 0, hi = list.Count - 1;
+			while (lo <= hi)
+			{
+				int mid = lo + ((hi - lo) >> 1);
+				int cmp = ((IComparer<Pair>)this).Compare(list[mid], value);
+				if (cmp == 0)
+					return mid;
+				if (cmp < 0)
+					lo = mid + 1;
+				else
+					hi = mid - 1;
+			}
+			return ~lo;
+		}
+	}
+}