Gform_delete_entry - how to conditionally block action using php

As I understand it, if someone clicks the delete button for an entry, the gform_delete_entry action fires before the entry is deleted. Is there a way to block the delete from proceeding? I want to use some php to check if the user can delete that particular entry and if the answer is no, block the delete, ideally with some sort of error message.

Another option would be a way to hide/disable the delete button when the form is loaded, again using some logic in php to determine when to hide the delete button. This is actually the preferred primary option although it would be good to also block the delete as I described above. I could handle most of hiding the delete button with Javascript and jQuery but need to know how to target the delete button in the same way that you can target form fields to add cssClasses, set default values and so on.