sketchy.rb

#!/usr/bin/env ruby

require 'optparse'
require 'pathname'
require 'tmpdir'

libraries = %w|/Applications/Processing.app/Contents/Resources/Java/core.jar|
compiler = 'scalac'
OptionParser.new {|opt|
  opt.on('-w', '--watch') { compiler = 'fsc' }
}.parse!(ARGV)

template = DATA.read
sources = ARGV.map {|s| Pathname.new(s).expand_path }

compile_and_run = lambda {
  File.open('Sketch.scala', 'w') {|f|
    f << template % sources.map {|s| s.read }.join("\n")
  }

  begin
    env = { 'CLASSPATH' => libraries.join(':') + ':.' }
    pid = spawn(env, compiler, 'Sketch.scala')
    puts 'Compiling...'
    if Process.detach(pid).value.success?
      pid = spawn(env, 'scala', 'Sketch')
      puts 'Run!'
      Process.waitpid(pid)
    end
    pid = nil
  ensure
    Process.kill(:INT, pid) if pid
  end
}

Dir.mktmpdir do |dir|
  Dir.chdir(dir)

  case compiler
  when 'scalac'
    compile_and_run.call
  when 'fsc'
    Signal.trap(:INT) { exit }

    thread = nil
    t = Time.at(0)
    loop do
      if sources.any? {|s| s.file? && s.mtime > t }
        t = Time.now
        thread.kill if thread
        thread = Thread.new(&compile_and_run)
      end

      sleep 1
    end
  end
end

__END__
import processing.core._
import PConstants._
import PApplet._

object Sketch {
    def main(args:Array[String]) {
        PApplet.main(Array("--location=5,25", classOf[Sketch].getName))
    }
}

class Sketch extends PApplet {
    lazy val proxy = new Proxy(this) {
        %s
    }

    override def setup() { proxy.setup() }
    override def draw() { proxy.draw() }

    override def mousePressed() { proxy.mousePressed() }
    override def mouseReleased() { proxy.mouseReleased() }
    override def mouseClicked() { proxy.mouseClicked() }
    override def mouseDragged() { proxy.mouseDragged() }
    override def mouseMoved() { proxy.mouseMoved() }

    abstract class Proxy(val applet:PApplet) {
        def setup() {}
        def draw()

        def mousePressed() {}
        def mouseReleased() {}
        def mouseClicked() {}
        def mouseDragged() {}
        def mouseMoved() {}

        def mouseX = applet.mouseX
        def mouseY = applet.mouseY
        def isMousePressed:Boolean = applet.mousePressed
        def isKeyPressed:Boolean = applet.keyPressed
    }

    implicit def double2float(x:Double):Float = x.toFloat
}