PowerArgs.Cli.Grid.PageUp C# (CSharp) Method

        public void PageUp()
        {
            if(SelectedIndex > visibleRowOffset)
            {
                SelectedIndex = visibleRowOffset;
            }
            else
            {
                visibleRowOffset -= NumRowsInView - 1;
                if (visibleRowOffset < 0) visibleRowOffset = 0;

                this.query.Skip = visibleRowOffset;
                DataView = DataSource.GetDataView(query);
            }

            if (SelectedIndex - visibleRowOffset < DataView.Items.Count)
            {
                SelectedItem = DataView.Items[SelectedIndex - visibleRowOffset];
            }
        }