I’ve actually spent a great deal of time researching this question: how
does one build a GUI app with Ruby? To answer your question here, there
are
basically two roads, in MRI (that’s Matz’s Ruby Implementation, the
non-java ruby) there are a handful of GUI libraries, all of them binding
to
one of the C/C++ toolkits: Gnome/GTK, QT, Wx, Gosu(for games) etc. The
second option is to use JRuby, and either work directly with one of the
Java toolkits (Swing, SWT, JavaFX) , or use one of the libraries that
wraps/abstacts/builds on top of those toolkits (Monkeybars, Rubeus,
Limelight, JRubyFX). Shoes has also been mentioned. It is undergoing a
rewrite that will use JRuby to provide a wrapper around SWT.
Your suggestion of using one of the MRI GUI libraries, from JRuby, would
make a lot of sense (portability of code, etc) except that all of those
libraries bind to various C libraries, and support for that in JRuby is,
well, currently unsupported. C-Ext support was offered as an experiment,
in
a previous version of JRuby (to the best of my understanding) but (again
to
the best of my understanding), it was buggy, difficult to maintain, and
essentially working against the tool. I believe it is still possible to
invoke JRuby with C-Extension support enabled, but I think for something
as
complex as a GUI toolkit, you’d have a hard time getting it working. You
could possibly bind to one of those libraries via JNI/FFI support, but
again, at this point you are basically working against the tool,
creating a
lot of trouble for yourself, to get something working which would never
really be a good fit for each other. And quite possibly you would end up
writing far, far more java code than had you just written your app using
one of those Java GUI toolkits you seem to want to avoid.
So, after all this research, what have I chosen for my projects going
forward? JRubyFX, 100%. One, JavaFX is a really nice, modern GUI
toolkit,
with a lot of manhours being poured into improving it. It uses CSS for
styling, has a great GUI builder (SceneBuilder), which produces FXML
(which
is quite readable/writable on its own), it performs well, and I could go
on
and on. It’s really easy to create your own widgets, components, etc in
JavaFX (or JRubyFX), and there’s tons of great documentation, blog
posts,
and other info easily available for it. Two, JRubyFX provides a very
ruby-ish wrapper around this, and its getting better all the time as
byteit101 has been putting a ton of work into making it a top-notch
framework. Three, efforts are currently underway to get JavaFX running
on
iOS and Android (it’s been done in Oracle’s lab, and they’ve opensourced
their proto-types). This means, it may eventually be possible to write
JRubyFX apps targeting those devices as well (This one’s a big maybe, of
course, but Android, at least, should be a very real possibility. This
stuff about the mobile stuff is just speculation on my part, nobody from
JRubyFX is doing any work on this stuff at the moment, or looking at it,
that I know of, but it’s something I am personally very intrigued by).
Four, javafx provides some really slick packaging tools for easily
building
native installers for Windows, Linux and OSX. We’ve already integrated
that
support (in basic form, with information on how to customize it
available)
into JRubyFX. Finally, Oracle themselves have stated that JavaFX is the
replacement for Swing, and that they will be phasing Swing out in favor
of
FX.
Hope that helped answer your questions, and I hope I’ve convinced you to
go
checkout JRubyFX. It’s awesome-sauce.