Alsing.Windows.Forms.SyntaxBox.Selection.Indent C# (CSharp) Method

        public void Indent()
        {
            if (!IsValid)
                return;

            Row xtr = null;
            var ActionGroup = new UndoBlockCollection();
            for (int i = LogicalBounds.FirstRow;
                 i <=
                 LogicalBounds.LastRow;
                 i++)
            {
                xtr = Control.Document[i];
                xtr.Text = "\t" + xtr.Text;
                var b = new UndoBlock();
                b.Action = UndoAction.InsertRange;
                b.Text = "\t";
                b.Position.X = 0;
                b.Position.Y = i;
                ActionGroup.Add(b);
            }
            if (ActionGroup.Count > 0)
                Control.Document.AddToUndoList(ActionGroup);
            Bounds = LogicalBounds;
            Bounds.FirstColumn = 0;
            Bounds.LastColumn = xtr.Text.Length;
            Control.Caret.Position.X = LogicalBounds.LastColumn;
            Control.Caret.Position.Y = LogicalBounds.LastRow;
        }