@NotNull
  public Change[] getSelectedChanges() {
    Set<Change> changes = new LinkedHashSet<Change>();

    final TreePath[] paths = getSelectionPaths();
    if (paths == null) {
      return new Change[0];
    }

    for (TreePath path : paths) {
      ChangesBrowserNode<?> node = (ChangesBrowserNode) path.getLastPathComponent();
      changes.addAll(node.getAllChangesUnder());
    }

    if (changes.isEmpty()) {
      final List<VirtualFile> selectedModifiedWithoutEditing = getSelectedModifiedWithoutEditing();
      if (selectedModifiedWithoutEditing != null && !selectedModifiedWithoutEditing.isEmpty()) {
        for (VirtualFile file : selectedModifiedWithoutEditing) {
          AbstractVcs vcs = ProjectLevelVcsManager.getInstance(myProject).getVcsFor(file);
          if (vcs == null) continue;
          final VcsCurrentRevisionProxy before =
              VcsCurrentRevisionProxy.create(file, myProject, vcs.getKeyInstanceMethod());
          if (before != null) {
            ContentRevision afterRevision = new CurrentContentRevision(new FilePathImpl(file));
            changes.add(new Change(before, afterRevision, FileStatus.HIJACKED));
          }
        }
      }
    }

    return changes.toArray(new Change[changes.size()]);
  }
    @Override
    public void calcData(final DataKey key, final DataSink sink) {
      Node node = getSelectedNode();

      if (key == PlatformDataKeys.PROJECT) {
        sink.put(PlatformDataKeys.PROJECT, myProject);
      } else if (key == USAGE_VIEW_KEY) {
        sink.put(USAGE_VIEW_KEY, UsageViewImpl.this);
      } else if (key == PlatformDataKeys.NAVIGATABLE_ARRAY) {
        sink.put(PlatformDataKeys.NAVIGATABLE_ARRAY, getNavigatablesForNodes(getSelectedNodes()));
      } else if (key == PlatformDataKeys.EXPORTER_TO_TEXT_FILE) {
        sink.put(PlatformDataKeys.EXPORTER_TO_TEXT_FILE, myTextFileExporter);
      } else if (key == USAGES_KEY) {
        final Set<Usage> selectedUsages = getSelectedUsages();
        sink.put(
            USAGES_KEY,
            selectedUsages != null
                ? selectedUsages.toArray(new Usage[selectedUsages.size()])
                : null);
      } else if (key == USAGE_TARGETS_KEY) {
        sink.put(USAGE_TARGETS_KEY, getSelectedUsageTargets());
      } else if (key == PlatformDataKeys.VIRTUAL_FILE_ARRAY) {
        final Set<Usage> usages = getSelectedUsages();
        Usage[] ua = usages != null ? usages.toArray(new Usage[usages.size()]) : null;
        VirtualFile[] data = UsageDataUtil.provideVirtualFileArray(ua, getSelectedUsageTargets());
        sink.put(PlatformDataKeys.VIRTUAL_FILE_ARRAY, data);
      } else if (key == PlatformDataKeys.HELP_ID) {
        sink.put(PlatformDataKeys.HELP_ID, HELP_ID);
      } else if (key == PlatformDataKeys.COPY_PROVIDER) {
        sink.put(PlatformDataKeys.COPY_PROVIDER, this);
      } else if (node != null) {
        Object userObject = node.getUserObject();
        if (userObject instanceof TypeSafeDataProvider) {
          ((TypeSafeDataProvider) userObject).calcData(key, sink);
        } else if (userObject instanceof DataProvider) {
          DataProvider dataProvider = (DataProvider) userObject;
          Object data = dataProvider.getData(key.getName());
          if (data != null) {
            sink.put(key, data);
          }
        }
      }
    }
  private Change[] getLeadSelection() {
    final Set<Change> changes = new LinkedHashSet<Change>();

    final TreePath[] paths = getSelectionPaths();
    if (paths == null) return new Change[0];

    for (TreePath path : paths) {
      ChangesBrowserNode node = (ChangesBrowserNode) path.getLastPathComponent();
      if (node instanceof ChangesBrowserChangeNode) {
        changes.add(((ChangesBrowserChangeNode) node).getUserObject());
      }
    }

    return changes.toArray(new Change[changes.size()]);
  }
  @NotNull
  private ChangeList[] getSelectedChangeLists() {
    Set<ChangeList> lists = new HashSet<ChangeList>();

    final TreePath[] paths = getSelectionPaths();
    if (paths == null) return new ChangeList[0];

    for (TreePath path : paths) {
      ChangesBrowserNode node = (ChangesBrowserNode) path.getLastPathComponent();
      final Object userObject = node.getUserObject();
      if (userObject instanceof ChangeList) {
        lists.add((ChangeList) userObject);
      }
    }

    return lists.toArray(new ChangeList[lists.size()]);
  }
  @Nullable
  private UsageTarget[] getSelectedUsageTargets() {
    TreePath[] selectionPaths = myTree.getSelectionPaths();
    if (selectionPaths == null) return null;

    Set<UsageTarget> targets = new THashSet<UsageTarget>();
    for (TreePath selectionPath : selectionPaths) {
      Object lastPathComponent = selectionPath.getLastPathComponent();
      if (lastPathComponent instanceof UsageTargetNode) {
        UsageTargetNode usageTargetNode = (UsageTargetNode) lastPathComponent;
        UsageTarget target = usageTargetNode.getTarget();
        if (target != null && target.isValid()) {
          targets.add(target);
        }
      }
    }

    return targets.isEmpty() ? null : targets.toArray(new UsageTarget[targets.size()]);
  }
 private void rulesChanged() {
   ApplicationManager.getApplication().assertIsDispatchThread();
   final ArrayList<UsageState> states = new ArrayList<UsageState>();
   captureUsagesExpandState(new TreePath(myTree.getModel().getRoot()), states);
   final List<Usage> allUsages = new ArrayList<Usage>(myUsageNodes.keySet());
   Collections.sort(allUsages, USAGE_COMPARATOR);
   final Set<Usage> excludedUsages = getExcludedUsages();
   reset();
   myBuilder.setGroupingRules(getActiveGroupingRules(myProject));
   myBuilder.setFilteringRules(getActiveFilteringRules(myProject));
   ApplicationManager.getApplication()
       .runReadAction(
           new Runnable() {
             @Override
             public void run() {
               for (Usage usage : allUsages) {
                 if (!usage.isValid()) {
                   continue;
                 }
                 if (usage instanceof MergeableUsage) {
                   ((MergeableUsage) usage).reset();
                 }
                 appendUsage(usage);
               }
             }
           });
   excludeUsages(excludedUsages.toArray(new Usage[excludedUsages.size()]));
   if (myCentralPanel != null) {
     setupCentralPanel();
   }
   SwingUtilities.invokeLater(
       new Runnable() {
         @Override
         public void run() {
           if (isDisposed) return;
           restoreUsageExpandState(states);
           updateImmediately();
         }
       });
 }