The QButton class is the abstract base class of button widgets, providing functionality common to buttons. ... void  toggle  ()  . ... QButton provides both push and toggle buttons. ... Only toggle buttons can be switched on and off (see below). isEnabled () determines whether the button can be pressed by the user. setAutoRepeat () determines whether the button will auto-repeat if the user holds it down. setToggleButton () determines whether the button is a toggle button or not. ... Draws the button. ...