Event that is emitted on a particular UI component when it requests focus for itself or a sibling component; handled by the component renderer if possible. Should not be propagated.
Note: This event is emitted by the
UIComponent.requestFocusmethod, and is usually not emitted directly by the application.
<TSource extends UIComponent>(source: TSource, direction?: UIFocusRequestType): UIFocusRequestEvent<TSource>
Event source UI component.