internal void ExtendSelection(
GridPanel panel, GridContainer endItem, bool extend)
{
int startIndex = panel.SelectionRowAnchor.GridIndex;
int endIndex = endItem.GridIndex;
panel.NormalizeIndices(false, 0, ref startIndex, ref endIndex);
if (panel.OnlyRowsSelected(startIndex, endIndex) == false)
{
if (extend == false)
panel.ClearAllSelected();
else
panel.ClearAll(false);
panel.SetSelectedRows(startIndex, endIndex - startIndex + 1, true);
GridContainer row = GetLastProcessedRow(panel);
if (extend == true && row != null)
startIndex = row.GridIndex;
InvalidateRows(panel, startIndex, endIndex, extend);
}
}