// makeNewComponent: func(Component) -> Component

//                   or Component

// returns new component

static Component awtReplaceComponent(final Component c, fO makeNewComponent) {

  if (c == null) null;

  ret (Component) swing(func { 

    Container parent = c.getParent();

    if (parent == null) null;

    Component[] l = parent.getComponents();

    LayoutManager layout = parent.getLayout();

    if (!(layout instanceof BorderLayout || layout instanceof ViewportLayout))

      warn("awtReplaceComponent only tested for BorderLayout/ViewportLayout. Have: " + layout);

    int idx = indexOf(l, c);

    if (idx < 0) fail("component not found in parent");

    //print("idx: " + idx);

    //print("Parent: " + parent);

    O constraints = callOpt(layout, "getConstraints", c);

    //print("Constraints: " + constraints);

    // remove

    parent.remove(c);

    // add new component  

    Component newComponent = (Component) (makeNewComponent instanceof Component ? makeNewComponent :  callF(makeNewComponent, c));

    parent.add(newComponent, constraints, idx);

    validateFrame(parent);

    ret newComponent;

  });

}