sclass SingleComponentPanel extends JPanel {
  *() { super(new BorderLayout); }

  *(Component component) {
    this();
    if (component != null) setComponent(component);
  }

  void setComponent(final Component component) {
    swing {
      removeAll();
      if (component != null)
        add(BorderLayout.CENTER, wrap(component));
      _revalidate(SingleComponentPanel.this);
    }
  }
  
  // Sometimes we need this?
  void setComponentAndRevalidateParent(Component component) {
    setComponent(component);
    main.revalidate(main.getParent(this));
  }
  
  void noComponent() { setComponent(null); }
  
  Component getComponent() {
    ret getComponentCount() == 0 ? null : getComponent(0);
  }
}