File Chooser in JRuby

Having convinced myself that the vanilla processing selectInput is a piece of crap (yet more reflection nonsense) I though I had better come up with an alternative for ruby processing, here is such an example (yielded by my good friend google and a bit of imagination, works for me):-

require 'rbconfig'
require 'pathname'

System = Java::JavaLang::System
JFile = Java::JavaIo::File
JXChooser = Java::javax::swing::JFileChooser

class ImageFilter < Java::javax::swing::filechooser::FileFilter
  def accept fobj
    return [".png",".jpg"].include? File.extname(fobj.to_s).downcase
    return fobj.isDirectory
  end

  def getDescription
    "Image Files"
  end
end


# Detect OS
OS = case RbConfig::CONFIG['host_os']
  when /darwin/      then :mac
  when /mswin|mingw/ then :windows
else
  :unix
end

# Asks the user to choose an editor.
# Returns either a Pathname object or nil (if canceled)
def pickImage
  # Create a FileChooser
  fc = JXChooser.new("Image Chooser")
  fc.set_dialog_title("Please select an image")
  fc.setFileFilter ImageFilter.new

  if :mac == OS
    fc.setCurrentDirectory(JFile.new(System.getProperty("user.home") << "/Pictures"))
  elsif :windows == OS
    fc.setCurrentDirectory(JFile.new(System.getProperty("user.dir")))
  else
    fc.setCurrentDirectory(JFile.new(System.getProperty("user.home")))
  end

  success = fc.show_open_dialog(nil)
  if success == JXChooser::APPROVE_OPTION
    return Pathname.new(fc.get_selected_file.get_absolute_path)
  else
    nil
  end
end

puts "The user picked: #{pickImage}"

# EOF

This would be the wrapper for ruby-processing?

def select_input(*args, &block)
  if block_given?
    # code using FileChooser output?
  else
    raise ArgumentError, "select_input must be called with a block" , caller
  end
end