public static void initLafSync( JFrame frame ) {
		((JComponent)frame.getContentPane()).registerKeyboardAction(
			e -> enableDisableLafSync(),
			KeyStroke.getKeyStroke( "alt shift S" ),
			JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT );

		if( state.getBoolean( KEY_LAF_SYNC, false ) ) {
			System.out.println( "FlatLaf: theme sync enabled; use Alt+Shift+S to disable it" );
			listenToLafChange();
		}
	}
register Alt+Shift+F1, F2, ... F12 keys to change system scale factor
flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoPrefs.java