sclass StackLayouter extends F1<Container, Dimension> {
  Map<Component, Int> heights = weakHashMap();
  int gap = 5;
  //int defaultHeight = 50;
  int preferredWidth = 300;
  
  Dimension get(Container parent) {
    Insets insets = parent.getInsets();
    Dimension size = parent.getSize();
    int y = insets.top;
    int width = size.width-insets.left-insets.right;
    L<Component> l = getComponents(parent);
    for (Component c : l) {
      Component c = l.get(i);
      bool big = contains(bigOnes, i);
      double H = heights.get(c);
      double h = H != null ? H : c.getPreferredSize().height;
      c.setBounds(insets.left, y, width, h);
      y += h+gap;
    }
    
    // return preferred size (hm.)
    ret new Dimension(preferredWidth, y+insets.bottom);
  };
}