!7

import javax.swing.tree.*;

p-substance {
  DefaultMutableTreeNode rootNode = new("root");
  rootNode.add(new DefaultMutableTreeNode("dummy"));
  //rootNode.setAllowsChildren(true);
  JTree tree = new JTree(rootNode);
  //tree.setRootVisible(true);
  tree.setShowsRootHandles(true);
  tree.collapseRow(0);
  
  //tree.addTreeExpansionListener(this);
  
  tree.addTreeWillExpandListener(new TreeWillExpandListener {
    public void treeWillCollapse(TreeExpansionEvent e) {}
    public void treeWillExpand(TreeExpansionEvent e) throws ExpandVetoException {
      print("treeWillExpand");
    }
  });
  
  showFrame(jscroll(tree));
}