SMART datagrid v.1 > Classes > ColumnGroup
Return previous Column object of column specified by parameter. If it is the column not being included or displayed in this group, or it is the first column, it will return null.
var idx = grid.focusedIndex();
var col = idx.column();
if (col && col.group()) {
col = col.group().prev();
if (col) {
grid.setFocusedIndex(grid.getIndex(idx.I(), col);
}
}