1 files changed, 80 insertions, 0 deletions
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Editing/TextSegmentReadOnlySectionProvider.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Editing/TextSegmentReadOnlySectionProvider.cs
new file mode 100644
index 000000000..c582301d4
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Editing/TextSegmentReadOnlySectionProvider.cs
@@ -0,0 +1,80 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+using Tango.Scripting.Editors.Document;
+
+namespace Tango.Scripting.Editors.Editing
+{
+	/// <summary>
+	/// Implementation for <see cref="IReadOnlySectionProvider"/> that stores the segments
+	/// in a <see cref="TextSegmentCollection{T}"/>.
+	/// </summary>
+	public class TextSegmentReadOnlySectionProvider<T> : IReadOnlySectionProvider where T : TextSegment
+	{
+		readonly TextSegmentCollection<T> segments;
+		
+		/// <summary>
+		/// Gets the collection storing the read-only segments.
+		/// </summary>
+		public TextSegmentCollection<T> Segments {
+			get { return segments; }
+		}
+		
+		/// <summary>
+		/// Creates a new TextSegmentReadOnlySectionProvider instance for the specified document.
+		/// </summary>
+		public TextSegmentReadOnlySectionProvider(TextDocument textDocument)
+		{
+			segments = new TextSegmentCollection<T>(textDocument);
+		}
+		
+		/// <summary>
+		/// Creates a new TextSegmentReadOnlySectionProvider instance using the specified TextSegmentCollection.
+		/// </summary>
+		public TextSegmentReadOnlySectionProvider(TextSegmentCollection<T> segments)
+		{
+			if (segments == null)
+				throw new ArgumentNullException("segments");
+			this.segments = segments;
+		}
+		
+		/// <summary>
+		/// Gets whether insertion is possible at the specified offset.
+		/// </summary>
+		public virtual bool CanInsert(int offset)
+		{
+			foreach (TextSegment segment in segments.FindSegmentsContaining(offset)) {
+				if (segment.StartOffset < offset && offset < segment.EndOffset)
+					return false;
+			}
+			return true;
+		}
+		
+		/// <summary>
+		/// Gets the deletable segments inside the given segment.
+		/// </summary>
+		public virtual IEnumerable<ISegment> GetDeletableSegments(ISegment segment)
+		{
+			if (segment == null)
+				throw new ArgumentNullException("segment");
+			
+			int readonlyUntil = segment.Offset;
+			foreach (TextSegment ts in segments.FindOverlappingSegments(segment)) {
+				int start = ts.StartOffset;
+				int end = start + ts.Length;
+				if (start > readonlyUntil) {
+					yield return new SimpleSegment(readonlyUntil, start - readonlyUntil);
+				}
+				if (end > readonlyUntil) {
+					readonlyUntil = end;
+				}
+			}
+			int endOffset = segment.EndOffset;
+			if (readonlyUntil < endOffset) {
+				yield return new SimpleSegment(readonlyUntil, endOffset - readonlyUntil);
+			}
+		}
+	}
+}