After yet another inspiring presentation by Romain Guy at last year’s JavaPolis, I’ve taken more interest in programming Swing. I programmed desktop applications for many years, using mostly Delphi. Now, after some years of web application development, discovering Swing is like finding back a long-lost friend. Why oh why did we ever turn our backs on desktop programming and open this Pandora’s box of browser incompatibilities, stylesheet hacking, a multitude of web frameworks, html files full of JavaScript, JSP files full of scriptlets, back-button-workarounds etcetera etcetera?[1] Fortunately for me, after about ten years of existence, Swing finally has a decent GUI builder as well: Matisse–even if I have to endure NetBeans to use it. At the moment, I’m working on a Swing-based variant of Picasa‘s auto-collage function (which is a nice idea but only has limited functionality).

You will probably know that Swing GUIs can be programmed as well as designed with a GUI builder. That is generally not a very pleasant activity: the code is verbose and you don’t see what you get right away. Following the ancient principle of “use the best programming language for the job, and if there isn’t one, invent a new language”, Chris Oliver developed F3, a Java-based declarative language for GUI development. In other words, a fine example of a Domain Specific Language. So maybe it was only a matter of time before someone took Ruby (great for implementing DSLs), JRuby and F3, connected the dots, and created an Ruby implementation of F3 for the Java platform. That someone is Jean Lazarou, and he named his creation Swiby. Swiby looks something like this:

require 'swiby'

class HelloWorldModel
  attr_accessor :saying
end

model = HelloWorldModel.new
model.saying = "Hello World"

Frame {
  title "Hello World F3"
  width 200
  content {
    Label {
      text bind(model, :saying)
    }
  }
  visible true
}

The question remains what you would use this for. For designing GUIs, I would still want to use a GUI builder like Matisse rather than having to code everything myself. Maybe the GUI builder could be made to generate F3/Swiby instead of spitting out endless lines of badly formatted Java gibberish. Maybe it could be made to work with a Ruby GUI library, for fast prototyping. Or maybe the Swiby code could even be used to generate… a web application?

[1] I’m not serious here, of course. I really love the browser and everything that comes with it.