I have a IToolControl derived control which contains a c# TextBox. In the IToolControl::OnSetFocus function documentation, it states that you need to call ICompletionNotify::SetComplete() when it's finished to let the application know that the control should lose focus. On another IToolControl combobox control, I called the SetComplete function on the DropDownClosed event. On which TextBox event should I call ICompletionNotify.SetComplete?