private void updateRightTreeModel() {
   Set<PsiFile> deps = new HashSet<PsiFile>();
   Set<PsiFile> scope = getSelectedScope(myLeftTree);
   myIllegalsInRightTree = new HashSet<PsiFile>();
   for (PsiFile psiFile : scope) {
     Map<DependencyRule, Set<PsiFile>> illegalDeps = myIllegalDependencies.get(psiFile);
     if (illegalDeps != null) {
       for (final DependencyRule rule : illegalDeps.keySet()) {
         myIllegalsInRightTree.addAll(illegalDeps.get(rule));
       }
     }
     final Set<PsiFile> psiFiles = myDependencies.get(psiFile);
     if (psiFiles != null) {
       for (PsiFile file : psiFiles) {
         if (file != null && file.isValid()) {
           deps.add(file);
         }
       }
     }
   }
   deps.removeAll(scope);
   myRightTreeExpansionMonitor.freeze();
   myRightTree.setModel(buildTreeModel(deps, myRightTreeMarker));
   myRightTreeExpansionMonitor.restore();
   expandFirstLevel(myRightTree);
 }
 @Nullable
 private AnalysisScope getScope() {
   final Set<PsiFile> selectedScope = getSelectedScope(myRightTree);
   Set<PsiFile> result = new HashSet<PsiFile>();
   ((PackageDependenciesNode) myLeftTree.getModel().getRoot())
       .fillFiles(result, !mySettings.UI_FLATTEN_PACKAGES);
   selectedScope.removeAll(result);
   if (selectedScope.isEmpty()) return null;
   List<VirtualFile> files = new ArrayList<VirtualFile>();
   final ProjectFileIndex fileIndex = ProjectRootManager.getInstance(myProject).getFileIndex();
   for (PsiFile psiFile : selectedScope) {
     final VirtualFile file = psiFile.getVirtualFile();
     LOG.assertTrue(file != null);
     if (fileIndex.isInContent(file)) {
       files.add(file);
     }
   }
   if (!files.isEmpty()) {
     return new AnalysisScope(myProject, files);
   }
   return null;
 }