XPTable.Models.Table.GetNewIndexFromPageUp C# (CSharp) Method

        private int GetNewIndexFromPageUp()
        {
            int i;
            if (!this.VScroll)
            {
                // Not enough data to scroll, so go to the top row
                i = 0;
            }
            else
            {
                int x = topIndex;
                int y = this.vScrollBar.Value - (this.vScrollBar.LargeChange - 1);

                if (this.FocusedCell.Row > topIndex && this.TableModel[topIndex, this.FocusedCell.Column].Enabled)
                {
                    // Focus is not on the topmost visible row, so without scrolling, put focus on the topmost row
                    i = topIndex;
                }
                else
                {
                    // We are already on the topmost visible row, so scroll up by a page
                    i = Math.Max(-1, this.vScrollBar.Value - (this.vScrollBar.LargeChange - 1));
                }
            }
            return i;
        }