private static void applySystemScaleFactor( JFrame frame, String scaleFactor ) {
		if( JOptionPane.showConfirmDialog( frame,
				"Change system scale factor to "
				+ (scaleFactor != null ? scaleFactor : "default")
				+ " and exit?",
				frame.getTitle(), JOptionPane.YES_NO_OPTION ) != JOptionPane.YES_OPTION )
			return;

		if( scaleFactor != null )
			state.put( KEY_SYSTEM_SCALE_FACTOR, scaleFactor );
		else
			state.remove( KEY_SYSTEM_SCALE_FACTOR );

		System.exit( 0 );
	}
register Alt+Shift+F1, F2, ... F12 keys to change system scale factor
flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoPrefs.java