AvalonStudio.TextEditor.Document.LineManager.Remove C# (CSharp) Method

		public void Remove(int offset, int length)
		{
			Debug.Assert(length >= 0);
			if (length == 0) return;
			var startLine = documentLineTree.GetByOffset(offset);
			var startLineOffset = startLine.Offset;

			Debug.Assert(offset < startLineOffset + startLine.TotalLength);
			if (offset > startLineOffset + startLine.Length)
			{
				Debug.Assert(startLine.DelimiterLength == 2);
				// we are deleting starting in the middle of a delimiter

				// remove last delimiter part
				SetLineLength(startLine, startLine.TotalLength - 1);
				// remove remaining text
				Remove(offset, length - 1);
				return;
			}

			if (offset + length < startLineOffset + startLine.TotalLength)
			{
				// just removing a part of this line
				//startLine.RemovedLinePart(ref deferredEventList, offset - startLineOffset, length);
				SetLineLength(startLine, startLine.TotalLength - length);
				return;
			}
			// merge startLine with another line because startLine's delimiter was deleted
			// possibly remove lines in between if multiple delimiters were deleted
			var charactersRemovedInStartLine = startLineOffset + startLine.TotalLength - offset;
			Debug.Assert(charactersRemovedInStartLine > 0);
			//startLine.RemovedLinePart(ref deferredEventList, offset - startLineOffset, charactersRemovedInStartLine);


			var endLine = documentLineTree.GetByOffset(offset + length);
			if (endLine == startLine)
			{
				// special case: we are removing a part of the last line up to the
				// end of the document
				SetLineLength(startLine, startLine.TotalLength - length);
				return;
			}
			var endLineOffset = endLine.Offset;
			var charactersLeftInEndLine = endLineOffset + endLine.TotalLength - (offset + length);
			//endLine.RemovedLinePart(ref deferredEventList, 0, endLine.TotalLength - charactersLeftInEndLine);
			//startLine.MergedWith(endLine, offset - startLineOffset);

			// remove all lines between startLine (excl.) and endLine (incl.)
			var tmp = startLine.NextLine;
			DocumentLine lineToRemove;
			do
			{
				lineToRemove = tmp;
				tmp = tmp.NextLine;
				RemoveLine(lineToRemove);
			} while (lineToRemove != endLine);

			SetLineLength(startLine, startLine.TotalLength - charactersRemovedInStartLine + charactersLeftInEndLine);
		}

        private void DoReplace(int offset, int length, ITextSource newText, OffsetChangeMap offsetChangeMap)
        {
            if (length == 0 && newText.TextLength == 0)
            {
                return;
            }

            // trying to replace a single character in 'Normal' mode?
            // for single characters, 'CharacterReplace' mode is equivalent, but more performant
            // (we don't have to touch the anchorTree at all in 'CharacterReplace' mode)
            if (length == 1 && newText.TextLength == 1 && offsetChangeMap == null)
            {
                offsetChangeMap = OffsetChangeMap.Empty;
            }

            ITextSource removedText;

            if (length == 0)
            {
                removedText = StringTextSource.Empty;
            }
            else if (length < 100)
            {
                removedText = new StringTextSource(rope.ToString(offset, length));
            }
            else
            {
                // use a rope if the removed string is long
                removedText = new RopeTextSource(rope.GetRange(offset, length));
            }
            var args = new DocumentChangeEventArgs(offset, removedText, newText, offsetChangeMap);

            // fire DocumentChanging event
            if (Changing != null)
            {
                Changing(this, args);
            }
            if (textChanging != null)
            {
                textChanging(this, args);
            }

            undoStack.Push(this, args);

            cachedText      = null; // reset cache of complete document text
            fireTextChanged = true;
            var delayedEvents = new DelayedEvents();

            lock (lockObject)
            {
                // create linked list of checkpoints
                versionProvider.AppendChange(args);

                // now update the textBuffer and lineTree
                if (offset == 0 && length == rope.Length)
                {
                    // optimize replacing the whole document
                    rope.Clear();
                    var newRopeTextSource = newText as RopeTextSource;
                    if (newRopeTextSource != null)
                    {
                        rope.InsertRange(0, newRopeTextSource.GetRope());
                    }
                    else
                    {
                        rope.InsertText(0, newText.Text);
                    }
                    lineManager.Rebuild();
                }
                else
                {
                    rope.RemoveRange(offset, length);
                    lineManager.Remove(offset, length);
#if DEBUG
                    lineTree.CheckProperties();
#endif
                    var newRopeTextSource = newText as RopeTextSource;
                    if (newRopeTextSource != null)
                    {
                        rope.InsertRange(offset, newRopeTextSource.GetRope());
                    }
                    else
                    {
                        rope.InsertText(offset, newText.Text);
                    }
                    lineManager.Insert(offset, newText);
#if DEBUG
                    lineTree.CheckProperties();
#endif
                }
            }

            // update text anchors
            if (offsetChangeMap == null)
            {
                anchorTree.HandleTextChange(args.CreateSingleChangeMapEntry(), delayedEvents);
            }
            else
            {
                foreach (var entry in offsetChangeMap)
                {
                    anchorTree.HandleTextChange(entry, delayedEvents);
                }
            }

            lineManager.ChangeComplete(args);

            // raise delayed events after our data structures are consistent again
            delayedEvents.RaiseEvents();

            // fire DocumentChanged event
            if (Changed != null)
            {
                Changed(this, args);
            }
            if (textChanged != null)
            {
                textChanged(this, args);
            }
        }