progressbardemo2.java

通讯采集软件

package collector.gui.test;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/*
 * ProgressBarDemo2.java is a 1.4 application that requires these files:
 *   LongTask.java
 *   SwingWorker.java
 */
public class ProgressBarDemo2
    extends JPanel
    implements ActionListener {
  public final static int ONE_SECOND = 1000;

  private JProgressBar progressBar;
  private Timer timer;
  private JButton startButton;
  private LongTask task;
  private JTextArea taskOutput;
  private String newline = "\n";

  public ProgressBarDemo2() {
    super(new BorderLayout());
    task = new LongTask();

    //Create the demo's UI.
    startButton = new JButton("Start");
    startButton.setActionCommand("start");
    startButton.addActionListener(this);

    progressBar = new JProgressBar(0, task.getLengthOfTask());
    progressBar.setValue(0);

    //We call setStringPainted, even though we don't want the
    //string to show up until we switch to determinate mode,
    //so that the progress bar height stays the same whether
    //or not the string is shown.
    progressBar.setStringPainted(true); //get space for the string
    progressBar.setString(""); //but don't paint it

    taskOutput = new JTextArea(5, 20);
    taskOutput.setMargin(new Insets(5, 5, 5, 5));
    taskOutput.setEditable(false);

    JPanel panel = new JPanel();
    panel.add(startButton);
    panel.add(progressBar);

    add(panel, BorderLayout.PAGE_START);
    add(new JScrollPane(taskOutput), BorderLayout.CENTER);
    setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));

    //Create a timer.
    timer = new Timer(ONE_SECOND, new ActionListener() {
      public void actionPerformed(ActionEvent evt) {
        progressBar.setValue(task.getCurrent());
        String s = task.getMessage();
        if (s != null) {
          if (progressBar.isIndeterminate()) {
            progressBar.setIndeterminate(false);
            progressBar.setString(null); //display % string
          }
          taskOutput.append(s + newline);
          taskOutput.setCaretPosition(
              taskOutput.getDocument().getLength());
        }
        if (task.isDone()) {
          Toolkit.getDefaultToolkit().beep();
          timer.stop();
          startButton.setEnabled(true);
          progressBar.setValue(progressBar.getMinimum());
          progressBar.setString(""); //hide % string
        }
      }
    });
  }

  /**
   * Called when the user presses the start button.
   */
  public void actionPerformed(ActionEvent evt) {
    progressBar.setIndeterminate(true);
    startButton.setEnabled(false);
    task.go();
    timer.start();
  }

  public static void main(String[] args) {
    //Make sure we have nice window decorations.
    JFrame.setDefaultLookAndFeelDecorated(true);

    //Create and set up the window.
    JFrame frame = new JFrame("ProgressBarDemo2");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    //Create and set up the content pane.
    JComponent newContentPane = new ProgressBarDemo2();
    newContentPane.setOpaque(true); //content panes must be opaque
    frame.setContentPane(newContentPane);

    //Display the window.
    frame.pack();
    frame.setVisible(true);
  }
}