Dialogs are something everyone wants, and also something most people
seem to have an opinion on! JavaFX 8u40 will have dialogs, but what form
they take (API-wise) is not yet defined. I've posted a relatively long
discussion on this over at FX Experience  and your feedback is highly
welcome. As I note in the blog post, the Jira issue for this feature is
RT-12643. If you have any thoughts, please do post them there (rather
than spam the many good people subscribed to openjfx-dev).