void (@NotNull Project project, Editor editor, PsiFile file, DataContext dataContext) { editor.getScrollingModel().scrollToCaret(ScrollType.MAKE_VISIBLE); final PsiElement targetMember = findTargetMember(element); if (targetMember == null) { final ChangeSignatureHandler handler = getChangeSignatureHandler(file); if (handler != null) { final String notFoundMessage = handler.getTargetNotFoundMessage(); if (notFoundMessage != null) { CommonRefactoringUtil.showErrorHint(project, editor, notFoundMessage, RefactoringBundle .message("changeSignature.refactoring.name"), null); } } return; } final ChangeSignatureHandler handler = getChangeSignatureHandler(targetMember); if (handler == null) return; handler.invoke(project, new PsiElement[]{targetMember}, dataContext); }