The QKeyEvent class contains parameters that describe a key event. ... QKeyEvent  ( int type, int key, int ascii, int state )  . ... void  accept  ()  . ... Key events occur when a key is pressed or released when a widget has keyboard input focus. A key event contains a special accept flag which tells whether the receiver wants the key. ... Constructs a key event object. ... Sets the accept flag of the key event object. ... Clears the accept flag parameter of the key event object. ...