Allow ISmartTextOutput to set the title of the decompilation tab.

ILSpy/ISmartTextOutput.cs

@@ -38,6 +38,11 @@ namespace ICSharpCode.ILSpy
 
 		void BeginSpan(HighlightingColor highlightingColor);
 		void EndSpan();
+
+		/// <summary>
+		/// Gets/sets the title displayed in the document tab's header.
+		/// </summary>
+		string Title { get; set; }
 	}
 
 	public static class SmartTextOutputExtensions

ILSpy/TextView/AvalonEditTextOutput.cs

@@ -81,6 +81,8 @@ namespace ICSharpCode.ILSpy.TextView
 		bool needsIndent;
 
 		public string IndentationString { get; set; } = "\t";
+
+		public string Title { get; set; }
 		
 		internal readonly List<VisualLineElementGenerator> elementGenerators = new List<VisualLineElementGenerator>();
 		

ILSpy/TextView/DecompilerTextView.cs

@@ -629,6 +629,10 @@ namespace ICSharpCode.ILSpy.TextView
 				foldingStrategy.UpdateFoldings(foldingManager, textEditor.Document);
 				Debug.WriteLine("  Updating folding: {0}", w.Elapsed); w.Restart();
 			}
+
+			if (this.DataContext is PaneModel model) {
+				model.Title = textOutput.Title;
+			}
 		}
 		#endregion
 		
@@ -751,6 +755,9 @@ namespace ICSharpCode.ILSpy.TextView
 		void DecompileNodes(DecompilationContext context, ITextOutput textOutput)
 		{
 			var nodes = context.TreeNodes;
+			if (textOutput is ISmartTextOutput smartTextOutput) {
+				smartTextOutput.Title = string.Join(", ", nodes.Select(n => n.ToString()));
+			}
 			for (int i = 0; i < nodes.Length; i++) {
 				if (i > 0)
 					textOutput.WriteLine();