JTabbedPaneのタブスクロールボタンで連続スクロールを実行する

class ActionRepeatHandler extends MouseAdapter implements ActionListener {
  // BasicScrollBarUI scrollSpeedThrottle
  private final static int scrollSpeedThrottle = 60; // delay in milli seconds
  private final Timer timer;
  private final Action action;
  private JButton button;

  protected ActionRepeatHandler(Action action) {
    super();
    this.action = action;
    timer = new Timer(scrollSpeedThrottle, this);
    timer.setInitialDelay(300);
  }

  @Override public void actionPerformed(ActionEvent e) {
    Object o = e.getSource();
    if (o instanceof Timer && button != null) {
      if (!button.getModel().isPressed() && timer.isRunning()) {
        timer.stop();
        button = null;
      } else {
        Component c = SwingUtilities.getAncestorOfClass(JTabbedPane.class, button);
        action.actionPerformed(new ActionEvent(c,
            ActionEvent.ACTION_PERFORMED, null,
            e.getWhen(), e.getModifiers()));
      }
    }
  }

  @Override public void mousePressed(MouseEvent e) {
    if (SwingUtilities.isLeftMouseButton(e) && e.getComponent().isEnabled()) {
      button = (JButton) e.getComponent();
      timer.start();
    }
  }

  @Override public void mouseReleased(MouseEvent e) {
    timer.stop();
    button = null;
  }

  @Override public void mouseExited(MouseEvent e) {
    if (timer.isRunning()) {
      timer.stop();
    }
  }
}