[Java] Domanda stupida su class

[rob_santini]

Salve a tutti.
Sono un neofita di java e avrei una domanda banale.
Sto creando una piccola applicazione con NetBeans e nel codice sorgente ho incollato questa classe:

class Example3  {

   //--- Private instances declarations
   private final static int POINTS_PER_INCH = 72;

   
   /**
    * Constructor: Example3 


    *
    */
   public Example3 () {
      
      //--- Create a new PrinterJob object
      PrinterJob printJob = PrinterJob.getPrinterJob ();

      //--- Create a new book to add pages to
      Book book = new Book ();

      //--- Add the cover page using the default page format for this print job
      book.append (new IntroPage (), printJob.defaultPage ());

      //--- Add the document page using a landscape page format
      PageFormat documentPageFormat = new PageFormat ();
      documentPageFormat.setOrientation (PageFormat.LANDSCAPE);
      book.append (new Document (), documentPageFormat);         

      //--- Add a third page using the same painter
      book.append (new Document (), documentPageFormat);         

      //--- Tell the printJob to use the book as the pageable object
      printJob.setPageable (book); 

      //--- Show the print dialog box. If the user click the 
      //--- print button we then proceed to print else we cancel
      //--- the process.
      if (printJob.printDialog()) {
         try {
            printJob.print();  
         } catch (Exception PrintException) {
            PrintException.printStackTrace();
         }
      }

   }

   /**
    * Class: IntroPage 


    * 
    * This class defines the painter for the cover page by implementing the
    * Printable interface. 


    *
    * @author Jean-Pierre Dube <jpdube@videotron.ca>
    * @version 1.0
    * @since 1.0
    * @see Printable
    */
   private class IntroPage implements Printable {


      /**
       * Method: print 


       *
       * @param g a value of type Graphics
       * @param pageFormat a value of type PageFormat
       * @param page a value of type int
       * @return a value of type int
       */
      public int print (Graphics g, PageFormat pageFormat, int page) {

         //--- Create the Graphics2D object
         Graphics2D g2d = (Graphics2D) g;

         //--- Translate the origin to 0,0 for the top left corner
         g2d.translate (pageFormat.getImageableX (), pageFormat.getImageableY ());

         //--- Set the default drawing color to black
         g2d.setPaint (Color.black);

         //--- Draw a border arround the page
         Rectangle2D.Double border = new Rectangle2D.Double (0, 
                                                             0, 
                                                             pageFormat.getImageableWidth (),
                                                             pageFormat.getImageableHeight ());
         g2d.draw (border);

         //--- Print the title
         String titleText = "Printing in Java Part 2";
         Font titleFont = new Font ("helvetica", Font.BOLD, 36);
         g2d.setFont (titleFont);

         //--- Compute the horizontal center of the page
         FontMetrics fontMetrics = g2d.getFontMetrics ();
         double titleX = (pageFormat.getImageableWidth () / 2) - (fontMetrics.stringWidth (titleText) / 2);
         double titleY = 3 * POINTS_PER_INCH;
         g2d.drawString (titleText, (int) titleX, (int) titleY);

         return (PAGE_EXISTS);
      }
   }



   /**
    * Class: Document 


    *
    * This class is the painter for the document content.


    *
    *
    * @author Jean-Pierre Dube <jpdube@videotron.ca>
    * @version 1.0
    * @since 1.0
    * @see Printable
    */
   private class Document implements Printable {


      /**
       * Method: print 


       *
       * @param g a value of type Graphics
       * @param pageFormat a value of type PageFormat
       * @param page a value of type int
       * @return a value of type int
       */
      public int print (Graphics g, PageFormat pageFormat, int page) {


         //--- Create the Graphics2D object
         Graphics2D g2d = (Graphics2D) g;

         //--- Translate the origin to 0,0 for the top left corner
         g2d.translate (pageFormat.getImageableX (), pageFormat.getImageableY ());

         //--- Set the drawing color to black
         g2d.setPaint (Color.black);

         //--- Draw a border arround the page using a 12 point border
         g2d.setStroke (new BasicStroke (12));
         Rectangle2D.Double border = new Rectangle2D.Double (0, 
                                                             0, 
                                                             pageFormat.getImageableWidth (),
                                                             pageFormat.getImageableHeight ());

         g2d.draw (border);


         //--- Print page 1
         if (page == 1) {
            //--- Print the text one inch from the top and laft margins
            g2d.drawString ("This the content page of page: " + page, POINTS_PER_INCH, POINTS_PER_INCH);
            return (PAGE_EXISTS);
         }

         //--- Print page 2
         else if (page == 2) {
            //--- Print the text one inch from the top and laft margins
            g2d.drawString ("This the content of the second page: " + page, POINTS_PER_INCH, POINTS_PER_INCH);
            return (PAGE_EXISTS);
         }
         

         //--- Validate the page
         return (NO_SUCH_PAGE);

      }
   }
   
} // Example3

Come faccio a richiamarla di un pulsante JButton?
grazie in anticipo dell'aiuto

[Alex'87]

Originariamente inviato da rob_santini
Come faccio a richiamarla di un pulsante JButton?
grazie in anticipo dell'aiuto

Aggiungi un ActionListener al tuo pulsante:

myButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        // istanzia qui la tua classe
    }
});