private static boolean isEnabled(DataContext dataContext) {
    Project project = CommonDataKeys.PROJECT.getData(dataContext);
    if (project == null
        || EditorGutter.KEY.getData(dataContext) != null
        || Boolean.TRUE.equals(dataContext.getData(CommonDataKeys.EDITOR_VIRTUAL_SPACE))) {
      return false;
    }

    Editor editor = CommonDataKeys.EDITOR.getData(dataContext);
    if (editor == null) {
      UsageTarget[] target = UsageView.USAGE_TARGETS_KEY.getData(dataContext);
      return target != null && target.length > 0;
    } else {
      PsiFile file = PsiDocumentManager.getInstance(project).getPsiFile(editor.getDocument());
      if (file == null) {
        return false;
      }

      Language language = PsiUtilBase.getLanguageInEditor(editor, project);
      if (language == null) {
        language = file.getLanguage();
      }
      return !(LanguageFindUsages.INSTANCE.forLanguage(language)
          instanceof EmptyFindUsagesProvider);
    }
  }
  @Nullable
  private static Commenter findCommenter(PsiFile file, Editor editor, Caret caret) {
    final FileType fileType = file.getFileType();
    if (fileType instanceof AbstractFileType) {
      return ((AbstractFileType) fileType).getCommenter();
    }

    Language lang = PsiUtilBase.getLanguageInEditor(caret, file.getProject());

    return getCommenter(file, editor, lang, lang);
  }
 private static void addCompletionChar(
     Project project,
     CompletionAssertions.WatchingInsertionContext context,
     LookupElement item,
     Editor editor,
     CompletionProgressIndicator indicator,
     char completionChar) {
   int tailOffset = context.getTailOffset();
   if (tailOffset < 0) {
     LOG.info(
         "tailOffset<0 after inserting "
             + item
             + " of "
             + item.getClass()
             + "; invalidated at: "
             + context.invalidateTrace
             + "\n--------");
   } else {
     editor.getCaretModel().moveToOffset(tailOffset);
   }
   if (context.getCompletionChar() == Lookup.COMPLETE_STATEMENT_SELECT_CHAR) {
     final Language language = PsiUtilBase.getLanguageInEditor(editor, project);
     if (language != null) {
       for (SmartEnterProcessor processor : SmartEnterProcessors.INSTANCE.forKey(language)) {
         if (processor.processAfterCompletion(editor, indicator.getParameters().getOriginalFile()))
           break;
       }
     }
   } else if (!editor
       .getCaretModel()
       .supportsMultipleCarets()) { // this will be done outside of runForEach caret context
     DataContext dataContext =
         DataManager.getInstance().getDataContext(editor.getContentComponent());
     EditorActionManager.getInstance()
         .getTypedAction()
         .getHandler()
         .execute(editor, completionChar, dataContext);
   }
 }