question: public void updateActions ( ) { String text ; Action a = RTextArea . getAction ( RTextArea . UNDO_ACTION ) ; if ( canUndo ( ) ) { a . setEnabled ( true ) ; text = getUndoPresentationName ( ) ; a . putValue ( Action . NAME , text ) ; a . putValue ( Action . SHORT_DESCRIPTION , text ) ; } else { if ( a . isEnabled ( ) ) { a . setEnabled ( false ) ; text = cantUndoText ; a . putValue ( Action . NAME , text ) ; a . putValue ( Action . SHORT_DESCRIPTION , text ) ; } } a = RTextArea . getAction ( RTextArea . REDO_ACTION ) ; if ( canRedo ( ) ) { a . setEnabled ( true ) ; text = getRedoPresentationName ( ) ; a . putValue ( Action . NAME , text ) ; a . putValue ( Action . SHORT_DESCRIPTION , text ) ; } else { if ( a . isEnabled ( ) ) { a . setEnabled ( false ) ; text = cantRedoText ; a . putValue ( Action . NAME , text ) ; a . putValue ( Action . SHORT_DESCRIPTION , text ) ; } } }
target:  Ensures that undo/redo actions are enabled appropriately and have descriptive text at all times.