1 files changed, 123 insertions, 0 deletions
diff --git a/main/src/addins/MonoDevelop.SourceEditor2/Mono.TextEditor/Gui/TextViewMargin.SpanUpdateListener.cs b/main/src/addins/MonoDevelop.SourceEditor2/Mono.TextEditor/Gui/TextViewMargin.SpanUpdateListener.cs
new file mode 100644
index 0000000000..f0700ee6ee
--- /dev/null
+++ b/main/src/addins/MonoDevelop.SourceEditor2/Mono.TextEditor/Gui/TextViewMargin.SpanUpdateListener.cs
@@ -0,0 +1,123 @@
+//
+// TextViewMargin.SpanUpdateListener.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.Linq;
+using System.Collections.Generic;
+using System.Text;
+using System.Runtime.InteropServices;
+
+using Mono.TextEditor.Highlighting;
+
+using MonoDevelop.Components.AtkCocoaHelper;
+
+using Gdk;
+using Gtk;
+using System.Timers;
+using System.Diagnostics;
+using MonoDevelop.Components;
+using MonoDevelop.Core;
+using MonoDevelop.Core.Text;
+using MonoDevelop.Ide.Editor;
+using MonoDevelop.Ide.Editor.Highlighting;
+using System.Collections.Immutable;
+using System.Threading;
+using MonoDevelop.Ide;
+using System.Threading.Tasks;
+
+namespace Mono.TextEditor
+{
+	partial class TextViewMargin
+	{
+		internal class SpanUpdateListener : IDisposable
+		{
+			readonly MonoTextEditor textEditor;
+
+			public bool HasUpdatedMultilineSpan { get; set; }
+
+			public SpanUpdateListener (MonoTextEditor textEditor)
+			{
+				this.textEditor = textEditor;
+				textEditor.Document.TextChanged += Document_TextChanged;
+				textEditor.Document.TextChanging += Document_TextChanging;
+			}
+
+			public void Dispose()
+			{
+				textEditor.Document.TextChanged -= Document_TextChanged;
+				textEditor.Document.TextChanging -= Document_TextChanging;
+			}
+
+			List<HighlightedLine> lines = new List<HighlightedLine> ();
+
+			void Document_TextChanging (object sender, TextChangeEventArgs e)
+			{
+				HasUpdatedMultilineSpan = false;
+				foreach (var change in e.TextChanges) {
+					var layout = textEditor.TextViewMargin.GetLayout (textEditor.GetLineByOffset (change.Offset));
+					lines.Add (layout.HighlightedLine);
+				}
+			}
+
+			void Document_TextChanged (object sender, TextChangeEventArgs e)
+			{
+				int i = 0;
+
+				foreach (var change in e.TextChanges) {
+					if (i >= lines.Count)
+						break; // should never happen
+					var oldHighlightedLine = lines [i++];
+					var curLine = textEditor.GetLineByOffset (change.Offset);
+					var curLayout = textEditor.TextViewMargin.GetLayout (curLine);
+					if (!UpdateLineHighlight (curLine.LineNumber, oldHighlightedLine, curLayout.HighlightedLine))
+						break;
+				}
+				lines.Clear ();
+			}
+
+			bool UpdateLineHighlight (int lineNumber, HighlightedLine oldLine, HighlightedLine newLine)
+			{
+				if (oldLine != null && ShouldUpdateSpan (oldLine, newLine)) {
+					textEditor.TextViewMargin.PurgeLayoutCacheAfter (lineNumber);
+					textEditor.QueueDraw ();
+					HasUpdatedMultilineSpan = true;
+					return false;
+				}
+				return true;
+			}
+
+			static bool ShouldUpdateSpan (HighlightedLine line1, HighlightedLine line2)
+			{
+				if (line1.IsContinuedBeyondLineEnd != line2.IsContinuedBeyondLineEnd)
+					return true;
+				if (line1.IsContinuedBeyondLineEnd == true) {
+					return line1.Segments.Last ().ScopeStack.Peek () != line2.Segments.Last ().ScopeStack.Peek ();
+				}
+				return false;
+			}
+		}
+	}
+}
+\ No newline at end of file