Function XPUDefocusKeyboard 

pub unsafe extern "C" fn XPUDefocusKeyboard(
    inMessage: XPWidgetMessage,
    inWidget: XPWidgetID,
    inParam1: isize,
    inParam2: isize,
    inEatClick: c_int,
) -> c_int

XPUDefocusKeyboard

This causes the widget to send keyboard focus back to X-Plane. This stops editing of any text fields, etc.