boolean function ( ) { return ( history . getLastCommand ( ) != null ) ; }
returns true , if the last executed command can be undone . concode_field_sep CommandHistory history concode_elem_sep Document document concode_elem_sep List<CommandListener> listeners concode_field_sep void undoMultipleSteps concode_elem_sep void undo concode_elem_sep void removeCommandListener concode_elem_sep Document getDocument concode_elem_sep void addCommandListener concode_elem_sep void redo concode_elem_sep void execute concode_elem_sep boolean isRedoPossible