Swing/TreeNodeProgressBar のバックアップ(No.6)

class ProgressBarRenderer extends DefaultTreeCellRenderer {
  private int nodeWidth = 100;
  private static int barHeight = 4;
  private final JProgressBar b = new JProgressBar(0, 100) {
    @Override public Dimension getPreferredSize() {
      Dimension d = super.getPreferredSize();
      d.height = barHeight;
      d.width  = nodeWidth;
      return d;
    }

    @Override public void updateUI() {
      super.updateUI();
      setUI(new BasicProgressBarUI());
    }
  };
  private final JPanel p = new JPanel(new BorderLayout());

  public ProgressBarRenderer() {
    super();
    b.setOpaque(false);
    p.setOpaque(false);
    b.setStringPainted(true);
    b.setString("");
    b.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
  }

  @Override public Component getTreeCellRendererComponent(
      JTree tree, Object value, boolean selected, boolean expanded,
      boolean leaf, int row, boolean hasFocus) {
    Object o = ((DefaultMutableTreeNode) value).getUserObject();
    JComponent c = (JComponent) super.getTreeCellRendererComponent(
        tree, value, selected, expanded, leaf, row, hasFocus);
    if (!(o instanceof ProgressObject)) {
      return c;
    }
    ProgressObject n = (ProgressObject) o;
    int i = n.getValue();
    b.setValue(i);

    FontMetrics metrics = c.getFontMetrics(c.getFont());
    int ww = getX() + getIcon().getIconWidth() + getIconTextGap()
      + metrics.stringWidth(n.title);
    nodeWidth = ww;

    p.removeAll();
    p.add(c);
    p.add(i < 100 ? b : Box.createVerticalStrut(barHeight), BorderLayout.SOUTH);
    return p;
  }
}