The QCloseEvent class contains parameters that describe a close event. ... void  accept  ()  . ... Close events are sent to widgets that the user wants to close, usually by choosing "Close" from the window menu. They are also sent when you call QWidget::close () to close a widget from inside the program. Close events contain a special accept flag which tells whether the receiver wants the widget to be closed. ... The event handler QWidget::closeEvent () receives close events. ...