The QWidget class is the base class of all user interface objects. ... To force those keys to be processed by your widget, you must override QWidget::event (). focusInEvent() - called when the widget gains keyboard focus (assuming you have called setFocusPolicy(), of course). ... Returns QWidget::TabFocus if the widget accepts focus by tabbing, QWidget::ClickFocus if the widget accepts focus by clicking, QWidget::StrongFocus if it accepts both and QWidget::NoFocus if it does not accept focus at all. ...