Another JavaFX Application Thread

[Mike Hearn]

That seems like a roundabout way to do things.

The web tells me:  "The asciidoctor.js project is a direct port of
Asciidoctor from Ruby to JavaScript using the Opal Ruby-to-JavaScript cross
compiler"

Why don't you use JRuby and run the original Asciidoctor code directly in a
background thread? That way, no webview is needed and it can all be done in
the background.