Alsing.SourceCode.SyntaxDocument.Redo C# (CSharp) Метод

        public TextPoint Redo()
        {
            if (UndoStep >= UndoBuffer.Count)
                return new TextPoint(-1, -1);

            UndoBlockCollection ActionGroup = UndoBuffer[UndoStep];
            UndoBlock undo = ActionGroup[0];
            for (int i = 0; i < ActionGroup.Count; i++)
            {
                undo = ActionGroup[i];

                switch (undo.Action)
                {
                    case UndoAction.InsertRange:
                        {
                            InsertText(undo.Text, undo.Position.X, undo.Position.Y, false);
                        }
                        break;
                    case UndoAction.DeleteRange:
                        {
                            TextRange r = GetRangeFromText(undo.Text, undo.Position.X, undo.Position.Y);
                            DeleteRange(r, false);
                        }
                        break;
                    default:
                        break;
                }
            }

            TextRange ran = GetRangeFromText(undo.Text, undo.Position.X, undo.Position.Y);
            UndoStep++;
            ResetVisibleRows();
            OnUndoBufferChanged();
            return new TextPoint(ran.LastColumn, ran.LastRow);
        }