question: public void actionPerformed ( ActionEvent e ) { File nextPage = null ; for ( Iterator iter = testFiles . iterator ( ) ; iter . hasNext ( ) ; ) { File f = ( File ) iter . next ( ) ; if ( f . equals ( currentDisplayed ) ) { if ( iter . hasNext ( ) ) { nextPage = ( File ) iter . next ( ) ; break ; } } } if ( nextPage == null ) { Iterator iter = testFiles . iterator ( ) ; nextPage = ( File ) iter . next ( ) ; } try { switchPage ( nextPage , false ) ; } catch ( Exception ex ) { ex . printStackTrace ( ) ; } }
target:  Invoked when an action occurs.