question: private void enableActions ( ) { restoreAction . setEnabled ( frame . isMaximum ( ) || frame . isIcon ( ) ) ; maximizeAction . setEnabled ( ( frame . isMaximizable ( ) && ! frame . isMaximum ( ) && ! frame . isIcon ( ) ) || ( frame . isMaximizable ( ) && frame . isIcon ( ) ) ) ; iconifyAction . setEnabled ( frame . isIconifiable ( ) && ! frame . isIcon ( ) ) ; closeAction . setEnabled ( frame . isClosable ( ) ) ; sizeAction . setEnabled ( false ) ; moveAction . setEnabled ( false ) ; }
target:  Set the enable/disabled state for the buttons.