private void traverseToLeaves(
     final PackageDependenciesNode treeNode,
     final StringBuffer denyRules,
     final StringBuffer allowRules) {
   final Enumeration enumeration = treeNode.breadthFirstEnumeration();
   while (enumeration.hasMoreElements()) {
     PsiElement childPsiElement =
         ((PackageDependenciesNode) enumeration.nextElement()).getPsiElement();
     if (myIllegalDependencies.containsKey(childPsiElement)) {
       final Map<DependencyRule, Set<PsiFile>> illegalDeps =
           myIllegalDependencies.get(childPsiElement);
       for (final DependencyRule rule : illegalDeps.keySet()) {
         if (rule.isDenyRule()) {
           if (denyRules.indexOf(rule.getDisplayText()) == -1) {
             denyRules.append(rule.getDisplayText());
             denyRules.append("\n");
           }
         } else {
           if (allowRules.indexOf(rule.getDisplayText()) == -1) {
             allowRules.append(rule.getDisplayText());
             allowRules.append("\n");
           }
         }
       }
     }
   }
 }
 public void actionPerformed(final AnActionEvent e) {
   @NonNls final String delim = "&nbsp;-&gt;&nbsp;";
   final StringBuffer buf = new StringBuffer();
   processDependencies(
       getSelectedScope(myLeftTree),
       getSelectedScope(myRightTree),
       new Processor<List<PsiFile>>() {
         public boolean process(final List<PsiFile> path) {
           if (buf.length() > 0) buf.append("<br>");
           buf.append(
               StringUtil.join(
                   path,
                   new Function<PsiFile, String>() {
                     public String fun(final PsiFile psiFile) {
                       return psiFile.getName();
                     }
                   },
                   delim));
           return true;
         }
       });
   final JEditorPane pane =
       new JEditorPane(UIUtil.HTML_MIME, "<html>" + buf.toString() + "</html>");
   pane.setForeground(Color.black);
   pane.setBackground(HintUtil.INFORMATION_COLOR);
   pane.setOpaque(true);
   final JScrollPane scrollPane = ScrollPaneFactory.createScrollPane(pane);
   final Dimension dimension = pane.getPreferredSize();
   scrollPane.setMinimumSize(new Dimension(dimension.width, dimension.height + 20));
   scrollPane.setPreferredSize(new Dimension(dimension.width, dimension.height + 20));
   JBPopupFactory.getInstance()
       .createComponentPopupBuilder(scrollPane, pane)
       .setTitle("Dependencies")
       .setMovable(true)
       .createPopup()
       .showInBestPositionFor(e.getDataContext());
 }