How to use Action interface?

Question

Hello,
I haven't been programming in JAVA for very long, just over a month. I understand that intefaces are just method signatures and variables that can be used by a class wich implements them and redefines the methods and/or variables. I know that much.. I think.
My Question:
I want to use the Action interface for multiple buttons, I just don't know exactly how. dubwai, is the one who suggested the concept to me. Does anyone have any implementation or code wich utilizes the Action interface?
Thanks very much,
Bruce

Answer 1

What you need to do is write a class that extends AbstractAction. I did one for a FileAction class. I have included the code for this below as a reference:
     class FileAction extends AbstractAction
          // Handles file actions
          FileAction(String name)
               //Constructor
               super(name);
               String iconFileName = "images/" + name + ".gif";
               if(new File(iconFileName).exists())
                    putValue(SMALL_ICON, new ImageIcon(iconFileName));
          FileAction(String name, String tooltip)
               //Constructor
               this(name);                                             // Call the other constructor
               if(tooltip != null)                                   // If there is tooltip text...
                    putValue(SHORT_DESCRIPTION, tooltip);     // store it.
          public void actionPerformed(ActionEvent e)
               String name = (String)getValue(NAME);
               if(name.equals(saveAction.getValue(NAME)))
                    // code to handle file Save operation
                    saveOperation();
               else if(name.equals(saveAsAction.getValue(NAME)))
                    // code to handle file Save As operation
                    File file = showDialog(
                         "Save Sketch As",
                         "Save",
                         "Save the Sketch",
                         's',
                         modelFile == null ? new File(files.getCurrentDirectory(), filename) : modelFile);
                    if (file != null)
                         if (file.exists() && ! file.equals(modelFile))
                              if (JOptionPane.NO_OPTION ==      //Overwrite warning
                                   JOptionPane.showConfirmDialog(
                                   SketchFrame.this,
                                   file.getName() + " exists. Overwrite?",
                                   "Confirm Save As",
                                   JOptionPane.YES_NO_OPTION,
                                   JOptionPane.WARNING_MESSAGE))
                              return;     // no file selected
                         saveSketch(file);
                    return;
               else if(name.equals(openAction.getValue(NAME)))
                    // code to handle file Open operation
                    checkForSave();
                    File file = showDialog("Open Sketch File",     // dialog window title
                         "Open",                                             // button lable
                         "Read a sketch from a file",               // button tooltip text
                         'o',                                             // shortcut character
                         null);                                             // no file selected
                    if (file != null)                                   // if a file was selected
                         openSketch(file);                              // then read it
               else if(name.equals(newAction.getValue(NAME)))
                    // code to handle file New operation
                    checkForSave();
                    theApp.insertModel(new SketchModel());          // insert new empty sketch
                    modelFile = null;                                   // no file for it
                    filename = DEFAULT_FILENAME;                    // default name
                    setTitle(frameTitle
                         + files.getCurrentDirectory()
                         + "\\"
                         + filename);
                    sketchChanged = false;                              // not changed yet
               else if(name.equals(exitAction.getValue(NAME)))
                    // code to handle file Exit operation
                    checkForSave();
                    System.exit(0);
               else if(name.equals(printAction.getValue(NAME)))
                    // code to handle file Print operation
                    PrinterJob printJob = PrinterJob.getPrinterJob();     // get a printing object
                    printJob.setPageable(theApp.getView());     // the view is the page source
                    if(printJob.printDialog())     // display print dialog
                         try
                              printJob.print();     // then print
                         catch(PrinterException pe)
                              System.out.println(pe);
                              JOptionPane.showMessageDialog(SketchFrame.this,
                                   "Error printing a sketch.",
                                   "Printer Error",
                                   JOptionPane.ERROR_MESSAGE);
     }The good thing about Actions is that you can put them in a menu or on a toolbar using the same code.
Garry.