Exemple #1
0
  /**
   * And now for a little assembly. Put together the buttons, progress bar and status text field.
   */
  Example1(String name) {
    setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.black), name));

    progressBar.setMaximum(NUMLOOPS);

    startButton = new JButton("Start");
    startButton.addActionListener(startListener);
    startButton.setEnabled(true);

    interruptButton = new JButton("Cancel");
    interruptButton.addActionListener(interruptListener);
    interruptButton.setEnabled(false);

    JComponent buttonBox = new JPanel();
    buttonBox.add(startButton);
    buttonBox.add(interruptButton);

    setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
    add(buttonBox);
    add(progressBar);
    add(statusField);
    statusField.setAlignmentX(CENTER_ALIGNMENT);

    buttonBox.setBorder(spaceBelow);
    Border pbBorder = progressBar.getBorder();
    progressBar.setBorder(BorderFactory.createCompoundBorder(spaceBelow, pbBorder));
  }
Exemple #2
0
class Example1 extends JPanel {
  JProgressBar progressBar = new JProgressBar();
  static int NUMLOOPS = 100;
  JLabel statusField = new JLabel("Click Start to begin", JLabel.CENTER);
  SwingWorker worker;
  JButton startButton;
  JButton interruptButton;
  Border spaceBelow = BorderFactory.createEmptyBorder(0, 0, 5, 0);

  JButton getStartButton() {
    return startButton;
  }

  /**
   * When the worker needs to update the GUI we do so by queuing a Runnable for the event
   * dispatching thread with SwingUtilities.invokeLater(). In this case we're just changing the
   * progress bars value.
   */
  void updateStatus(final int i) {
    Runnable doSetProgressBarValue =
        new Runnable() {
          public void run() {
            progressBar.setValue(i);
          }
        };
    SwingUtilities.invokeLater(doSetProgressBarValue);
  }

  /**
   * This method represents the application code that we'd like to run on a separate thread. It
   * simulates slowly computing a value, in this case just a string 'All Done'. It updates the
   * progress bar every half second to remind the user that we're still busy.
   */
  Object doWork() {
    try {
      for (int i = 0; i < NUMLOOPS; i++) {
        updateStatus(i);
        if (Thread.interrupted()) {
          throw new InterruptedException();
        }
        Thread.sleep(500);
      }
    } catch (InterruptedException e) {
      updateStatus(0);
      return "Interrupted"; // SwingWorker.get() returns this
    }
    return "All Done"; // or this
  }

  /**
   * This action listener, called by the "Start" button, effectively forks the thread that does the
   * work.
   */
  ActionListener startListener =
      new ActionListener() {
        public void actionPerformed(ActionEvent event) {
          startButton.setEnabled(false);
          interruptButton.setEnabled(true);
          statusField.setText("Working...");

          /* Constructing the SwingWorker() causes a new Thread
           * to be created that will call construct(), and then
           * finished().  Note that finished() is called even if
           * the worker is interrupted because we catch the
           * InterruptedException in doWork().
           */
          worker =
              new SwingWorker() {
                public Object construct() {
                  return doWork();
                }

                public void finished() {
                  startButton.setEnabled(true);
                  interruptButton.setEnabled(false);
                  statusField.setText(get().toString());
                }
              };
        }
      };

  /**
   * This action listener, called by the "Cancel" button, interrupts the worker thread which is
   * running this.doWork(). Note that the doWork() method handles InterruptedExceptions cleanly.
   */
  ActionListener interruptListener =
      new ActionListener() {
        public void actionPerformed(ActionEvent event) {
          interruptButton.setEnabled(false);
          worker.interrupt();
          startButton.setEnabled(true);
        }
      };

  /**
   * And now for a little assembly. Put together the buttons, progress bar and status text field.
   */
  Example1(String name) {
    setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.black), name));

    progressBar.setMaximum(NUMLOOPS);

    startButton = new JButton("Start");
    startButton.addActionListener(startListener);
    startButton.setEnabled(true);

    interruptButton = new JButton("Cancel");
    interruptButton.addActionListener(interruptListener);
    interruptButton.setEnabled(false);

    JComponent buttonBox = new JPanel();
    buttonBox.add(startButton);
    buttonBox.add(interruptButton);

    setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
    add(buttonBox);
    add(progressBar);
    add(statusField);
    statusField.setAlignmentX(CENTER_ALIGNMENT);

    buttonBox.setBorder(spaceBelow);
    Border pbBorder = progressBar.getBorder();
    progressBar.setBorder(BorderFactory.createCompoundBorder(spaceBelow, pbBorder));
  }

  Example1() {
    this("Example 1");
  }
}