fix #300: Implement 'Link Mode' (Script.Link)

src/AddIns/BackendBindings/CSharpBinding/Project/Src/Refactoring/EditorScript.cs

@@ -30,6 +30,7 @@ using System.Windows.Threading;
 using ICSharpCode.AvalonEdit;
 using ICSharpCode.AvalonEdit.Editing;
 using ICSharpCode.AvalonEdit.Rendering;
+using ICSharpCode.AvalonEdit.Snippets;
 using CSharpBinding.Parser;
 using ICSharpCode.AvalonEdit.Document;
 using ICSharpCode.NRefactory;
@@ -82,12 +83,31 @@ namespace CSharpBinding.Refactoring
 			editor.Select(startOffset, endOffset - startOffset);
 		}
 		
-		static readonly Task completedTask = Task.FromResult<object>(null);
-		
 		public override Task Link(params AstNode[] nodes)
 		{
-			// TODO
-			return completedTask;
+			var segs = nodes.Select(node => GetSegment(node)).ToArray();
+			InsertionContext c = new InsertionContext(editor.GetRequiredService<TextArea>(), segs.Min(seg => seg.Offset));
+			c.InsertionPosition = segs.Max(seg => seg.EndOffset);
+			
+			var tcs = new TaskCompletionSource<bool>();
+			c.Deactivated += (sender, e) => tcs.SetResult(true);
+			
+			if (segs.Length > 0) {
+				// try to use node in identifier context to avoid the code completion popup.
+				var identifier = nodes.OfType<Identifier>().FirstOrDefault();
+				ISegment first;
+				if (identifier == null)
+					first = segs[0];
+				else
+					first = GetSegment(identifier);
+				c.Link(first, segs.Except(new[]{first}).ToArray());
+				c.RaiseInsertionCompleted(EventArgs.Empty);
+			} else {
+				c.RaiseInsertionCompleted(EventArgs.Empty);
+				c.Deactivate(new SnippetEventArgs(DeactivateReason.NoActiveElements));
+			}
+			
+			return tcs.Task;
 		}
 		
 		public override Task<Script> InsertWithCursor(string operation, InsertPosition defaultPosition, IList<AstNode> nodes)

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Snippets/InsertionContext.cs

@@ -278,5 +278,25 @@ namespace ICSharpCode.AvalonEdit.Snippets
 			}
 			return false;
 		}
+		
+		/// <summary>
+		/// Adds existing segments as snippet elements.
+		/// </summary>
+		public void Link(ISegment mainElement, ISegment[] boundElements)
+		{
+			var main = new SnippetReplaceableTextElement { Text = Document.GetText(mainElement) };
+			RegisterActiveElement(main, new ReplaceableActiveElement(this, mainElement.Offset, mainElement.EndOffset));
+			foreach (var boundElement in boundElements) {
+				var bound = new SnippetBoundElement { TargetElement = main };
+				var start = Document.CreateAnchor(boundElement.Offset);
+				start.MovementType = AnchorMovementType.BeforeInsertion;
+				start.SurviveDeletion = true;
+				var end = Document.CreateAnchor(boundElement.EndOffset);
+				end.MovementType = AnchorMovementType.BeforeInsertion;
+				end.SurviveDeletion = true;
+				
+				RegisterActiveElement(bound, new BoundActiveElement(this, main, bound, new AnchorSegment(start, end)));
+			}
+		}
 	}
 }