ContextMenu with mutually exclusive behaviour (group/ungroup)

[Borralis]

Hi,

In a ContextMenu how do I make this:

- Show only "Group" option when the column is ungrouped (not for all the column, just for the column that is ungrouped).

- Show only "Ungroup" option when the column is grouped.

 

 

I tried this:

But this hides both (group/ungroup options)

void HeaderContextMenu_GroupsChanging(object sender, GridGroupsChangingEventArgs e)
{
    if (e.Action == GridGroupsChangingAction.Group)
           this.MasterTableView.GetColumn(e.Expression.GroupByFields[0].FieldName).Groupable = ...;
    else if (e.Action == GridGroupsChangingAction.Ungroup)
        this.MasterTableView.GetColumnSafe(e.Expression.GroupByFields[0].FieldName).Groupable = ...;
}

Any help?