Is there any way to show a button upon file open if and only if the PDF reader opening the file supports interactivity? That is, there's no point showing the button if the end user can't do anything with it.
It would be fine if the button showed if and only if the PDF reader opening the file is an Adobe product, but it's not a requirement.
Steps:
1. Open file
Expected result: If interactivity is supported (or if the reader is an Adobe product, doesn't matter), show the button.
The button is not part of a form, but rather is used to show and hide layers. It is okay if the expected result requires JavaScript, as if they have JavaScript disabled, they would get the same result as if they had no interactivity.
You could define an invisible button and have JavaScript to make it visible on open. Not guaranteed (because who knows what all PDF viewers will do) but worth trying.