The default implementation does nothing; the processing of accepted close events remains in the QWidget::event handler, so that subclasses don't have to call the super class in order to free window system resources and emit lastWindowClosed signals. QWidgetWindow::event is reimplemented to handle QEvent::Close as well, calling QWidgetPrivate::close_helper, which then delivers a separate QCloseEvent to the widget. The order of execution for widgets is after this change: 1) QWidgetWindow::event 2) QWidgetWindow::handleCloseEvent (calls QWidget::event/closeEvent) 3) QWindow::event 4) QWindow::closeEvent <- does nothing, not overridden 5) default cleanup handling in QWindow::event and for Qt Quick after the corresponding change in qtdeclarative: 1) QQuickWindow::event 2) QWindow::event 3) QQuickWindow::closeEvent <- emits closed 4) default cleanup handling in QWindow::event [ChangeLog][QtGui][QWindow] closeEvent has been added as a virtual function. Task-number: QTBUG-31019 Change-Id: I201f5ee9c6a73b949986648e3bd288d2c7898f28 Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io> Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>