JavaFX and iOS - it will remain a dream

[Niklas Therning]

> > > after many days trying to really build iOS apps with JavaFX and RoboVM
> or
> > > Avian I’m very frustrated because of the following things:
> > >
> > > Based on RoboVM, JavaFX on iOS runs unacceptable slow - I don’t know
> the
> > > reason - maybe it’s the rendering model of JavaFX - maybe it’s the
> > > currently unoptimized RoboVM
> > > One big problem of RoboVM is it’s dependence of the Android library, it
> > > does not support the OpenJDK. That’s a big reason for many many
> problems
> > > when using JavaFX. So currently it’s not possible to use fxml files
> > > (FXMLoader) because of the missing Stax xml parser and classes like
> > > XMLInputFactory in the android library…
>

There's now a compatibility library for the jfx78 backport which includes
the missing sun.* classes from OpenJDK [1]. So that will not be a problem
when running on RoboVM/Android. Daniel Zwolenski is working on getting this
into Maven which will make it nice and easy to develop with RoboVM+OpenJFX.

FXMLLoader relies an StAX and the Java Scripting API. Those can both be
made to work on RoboVM/Android. The POM of the compat project [1] contains
optional dependencies on the StAX API and JSR 223 API. For StAX you'll also
need a StAX provider [2][3]. For scripting you'll need a JSR 223
implementation of the scripting language you're using, like Rhino for
JavaScript [4][5]. Please note that I haven't tested FXML but it should
work (in theory at least ;-) ). Please give it a go. It will be a great
blog story if you can make it work on iOS.

As for the performance issues with RoboVM+OpenJFX: those WILL be addressed!
You can either wait for it to happen or you can help out. One way to do
that would be sample code that exercises the code paths that need to be
optimized (e.g. the button rendering you posted about earlier). Preferably
the sample should run repeatedly without user interaction. You should then
be able to run Apple's Instruments application to profile this sample. This
will help us determine what needs to be optimized.

/Niklas

[1] https://github.com/robovm/robovm-jfx78-compat
[2] https://github.com/FasterXML/aalto-xml
[3] http://woodstox.codehaus.org/
[4] https://developer.mozilla.org/en-US/docs/Rhino
[5]
https://java.net/projects/scripting/sources/svn/show/trunk/engines/javascript?rev=236