1 files changed, 140 insertions, 0 deletions
diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Editor.Extension/BlockStructureFoldingTextEditorExtension.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Editor.Extension/BlockStructureFoldingTextEditorExtension.cs
new file mode 100644
index 0000000000..6727ea5c80
--- /dev/null
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Editor.Extension/BlockStructureFoldingTextEditorExtension.cs
@@ -0,0 +1,140 @@
+//
+// BlockStructureFoldingTextEditorExtension.cs
+//
+// Author:
+//       Mike Krüger <mikkrg@microsoft.com>
+//
+// Copyright (c) 2018 Microsoft Corporation. All rights reserved.
+//
+// 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 System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using Gtk;
+using MonoDevelop.Core;
+using MonoDevelop.Core.Text;
+using MonoDevelop.Ide.Editor.Highlighting;
+using MonoDevelop.Ide.TypeSystem;
+using Microsoft.CodeAnalysis.Structure;
+using System.Collections.Immutable;
+
+namespace MonoDevelop.Ide.Editor.Extension
+{
+	class BlockStructureFoldingTextEditorExtension : TextEditorExtension
+	{
+		CancellationTokenSource src = new CancellationTokenSource ();
+		bool isDisposed;
+
+		protected override void Initialize ()
+		{
+			DocumentContext.DocumentParsed += DocumentContext_DocumentParsed;
+		}
+
+		public override void Dispose ()
+		{
+			if (isDisposed)
+				return;
+			isDisposed = true;
+			CancelDocumentParsedUpdate ();
+			DocumentContext.DocumentParsed -= DocumentContext_DocumentParsed;
+			base.Dispose ();
+		}
+
+		void CancelDocumentParsedUpdate ()
+		{
+			src.Cancel ();
+			src = new CancellationTokenSource ();
+		}
+
+		async void DocumentContext_DocumentParsed (object sender, EventArgs e)
+		{
+			CancelDocumentParsedUpdate ();
+			var analysisDocument = DocumentContext.AnalysisDocument;
+			if (analysisDocument == null || !Editor.Options.ShowFoldMargin)
+				return;
+			var caretLocation = Editor.CaretOffset;
+
+			var outliningService = BlockStructureService.GetService (analysisDocument);
+			if (outliningService == null)
+				return;
+			var token = src.Token;
+			var blockStructure = await outliningService.GetBlockStructureAsync (analysisDocument, token).ConfigureAwait (false);
+			UpdateFoldings (Editor, blockStructure.Spans, caretLocation, false, token);
+		}
+
+		static void UpdateFoldings (TextEditor Editor, ImmutableArray<BlockSpan> spans, int caretOffset, bool firstTime = false, CancellationToken token = default (CancellationToken))
+		{
+			try {
+				var foldSegments = new List<IFoldSegment> ();
+
+				foreach (var blockSpan in spans) {
+					if (token.IsCancellationRequested)
+						return;
+					if (!blockSpan.IsCollapsible)
+						continue;
+					var type = FoldingType.Unknown;
+					switch (blockSpan.Type) {
+					case BlockTypes.Member:
+						type = FoldingType.TypeMember;
+						break;
+					case BlockTypes.Type:
+						type = FoldingType.TypeDefinition;
+						break;
+					case BlockTypes.Comment:
+						type = FoldingType.Comment;
+						break;
+					default:
+						type = FoldingType.Unknown;
+						break;
+					}
+					var start = blockSpan.TextSpan.Start;
+					var end = blockSpan.TextSpan.End;
+					var marker = Editor.CreateFoldSegment (start, end - start);
+					if (marker == null)
+						continue;
+					foldSegments.Add (marker);
+					marker.CollapsedText = blockSpan.BannerText;
+					marker.FoldingType = type;
+					//and, if necessary, set its fold state
+					if (firstTime) {
+						// only fold on document open, later added folds are NOT folded by default.
+						marker.IsCollapsed = blockSpan.IsDefaultCollapsed;
+						continue;
+					}
+					if (blockSpan.TextSpan.Contains (caretOffset))
+						marker.IsCollapsed = false;
+				}
+				if (firstTime) {
+					Editor.SetFoldings (foldSegments);
+				} else {
+					Application.Invoke ((o, args) => {
+						if (!token.IsCancellationRequested)
+							Editor.SetFoldings (foldSegments);
+					});
+				}
+			} catch (OperationCanceledException) {
+			} catch (Exception ex) {
+				LoggingService.LogError ("Unhandled exception in ParseInformationUpdaterWorkerThread", ex);
+			}
+		}
+	}
+}
+\ No newline at end of file