public void invoke()

in src/org/intellij/grammar/refactor/BnfIntroduceRuleHandler.java [65:119]
52 lines of code
10 McCabe index (conditional complexity)

  public void invoke(@NotNull Project project, Editor editor, PsiFile file, @Nullable DataContext dataContext) {
    if (!(file instanceof BnfFileImpl)) return;

    BnfFile bnfFile = (BnfFileImpl)file;
    SelectionModel selectionModel = editor.getSelectionModel();
    int[] starts = selectionModel.getBlockSelectionStarts();
    int[] ends = selectionModel.getBlockSelectionEnds();
    if (starts.length == 0) return;

    int startOffset = starts[0];
    int endOffset = ends[ends.length-1];
    BnfRule currentRule = PsiTreeUtil.getParentOfType(file.findElementAt(startOffset), BnfRule.class);
    BnfExpression parentExpression = currentRule != null ? findParentExpression(bnfFile, startOffset, endOffset) : null;
    if (parentExpression == null) {
      CommonRefactoringUtil.showErrorHint(project, editor, RefactoringBundle.message("refactoring.introduce.context.error"), "Error", null);
      return;
    }

    if (!selectionModel.hasSelection()) {
      List<BnfExpression> expressions = new ArrayList<>();
      while (parentExpression != null) {
        expressions.add(parentExpression);
        parentExpression = PsiTreeUtil.getParentOfType(parentExpression, BnfExpression.class);
      }
      if (expressions.size() == 1) {
        invokeIntroduce(project, editor, file, currentRule, expressions);
      }
      else {
        if (myPopupVariantsHandler != null) {
          invokeIntroduce(project, editor, file, currentRule, Collections.singletonList(myPopupVariantsHandler.fun(expressions)));
        }
        else {
          IntroduceTargetChooser.showChooser(
            editor, expressions,
            new Pass<>() {
              @Override
              public void pass(BnfExpression bnfExpression) {
                invokeIntroduce(project, editor, file, currentRule,
                                Collections.singletonList(bnfExpression));
              }
            }, RENDER_FUNCTION, "Expressions"
          );
        }
      }
    }
    else {
      List<BnfExpression> selectedExpression = findSelectedExpressionsInRange(parentExpression, new TextRange(startOffset, endOffset));
      if (selectedExpression.isEmpty()) {
        CommonRefactoringUtil.showErrorHint(project, editor,
                                             RefactoringBundle.message("refactoring.introduce.selection.error"), "Error", null);
        return;
      }
      invokeIntroduce(project, editor, file, currentRule, selectedExpression);
    }
  }