Paint a JProgressBar with indeterminate progress status in a cell of a JTable

• download example.jar
• download src.zip
• repository

Code

private final JTable table = new JTable(model) {
  @Override public void updateUI() {
    super.updateUI();
    removeColumn(getColumnModel().getColumn(3));
    JProgressBar progress = new JProgressBar();
    TableCellRenderer renderer = new DefaultTableCellRenderer();
    TableColumn tc = getColumnModel().getColumn(2);
    tc.setCellRenderer((tbl, value, isSelected, hasFocus, row, column) -> {
      Component c;
      if (value instanceof JProgressBar) {
        c = (JProgressBar) value;
      } else if (value instanceof Integer) {
        progress.setValue((int) value);
        c = progress;
      } else {
        c = renderer.getTableCellRendererComponent(
            tbl, Objects.toString(value), isSelected, hasFocus, row, column);
      }
      return c;
    });
  }
};

class IndeterminateProgressBarUI extends BasicProgressBarUI {
  @Override public void incrementAnimationIndex() {
    super.incrementAnimationIndex();
  }
}

class BackgroundTask extends SwingWorker<Integer, Object> {
  private final Random rnd = new Random();

  @Override protected Integer doInBackground() throws InterruptedException {
    int lengthOfTask = calculateTaskSize();
    int current = 0;
    int total = 0;
    while (current <= lengthOfTask && !isCancelled()) {
      publish(100 * current / lengthOfTask);
      total += doSomething();
      current++;
    }
    return total;
  }

  private int calculateTaskSize() throws InterruptedException {
    int total = 0;
    JProgressBar indeterminate = new JProgressBar() {
      @Override public void updateUI() {
        super.updateUI();
        setUI(new IndeterminateProgressBarUI());
      }
    };
    indeterminate.setIndeterminate(true);
    // Indeterminate loop:
    for (int i = 0; i < 200; i++) {
      int iv = rnd.nextInt(50) + 1;
      Thread.sleep(iv);
      ProgressBarUI ui = indeterminate.getUI()
      ((IndeterminateProgressBarUI) ui).incrementAnimationIndex();
      publish(indeterminate);
      total += iv;
    }
    return 1 + total / 100;
  }

  private int doSomething() throws InterruptedException {
    int iv = rnd.nextInt(50) + 1;
    Thread.sleep(iv);
    return iv;
  }
}

References

• Java Swing Tips: JProgressBar in JTable Cell
• Paint a JProgressBar with indeterminate progress status in a cell of a JTable(Japanese)