How to handle file open requests on MacOS

[Mike Hearn]

What is Application.getApplication() here? The JavaFX Application class
does not have a setOpenFileHandler method. Is that a Mac-specific API?

It's too bad that 8u40 won't have this. Being able to easily open double
clicked files is pretty basic. Perhaps post 8u40 the JFX team could go
through Scene Builder and identify everywhere it relies on internal APIs or
custom magic and suck it into the core API, as then you'd have confidence
that an app of real complexity can be done entirely with documented stuff.