GIGO: words unreadable aloud

Scala Swing example

Here (below) is an example of Scala interacting with the java Swing GUI library, to put up a real silly GUI window. It's neither a good example of Swing usage, nor a good example of how much more clearly Scala can express some things than Java can; it's more of a "how-to", to show a little of how scala interacts with Java libraries. It works and does almost the same thing on Solaris (2.8), Windows XP, and Mac OS X (10.2.4).

Somewhat interesting tidbits:

I renamed JButton to JSwJB upon import.
The variable exitButton is initialized with an underscore, which tells scala to give it a "default initialization value".
I use "this." a lot; I think it should be required. It is not required in Scala, just as it is not required in Java.
In the mkExitButton method, I omitted the outermost {curly} braces. I'm still not sure that it's a good idea to make them omittable.
In the sbwob.init method, the call to mkExitButton does not need "()".
In the next line, the anonymous instance of the inner class "goAway" was created without requiring me to say "new goAway". That's because I declared the goAway class to be a "case class".
"goAway with foo" is how you say that class goAway implements the Java interface named foo.

//
// Translated into Scala from the jython version seen at
//   http://www.eros-os.org/pipermail/e-lang/2002-April/006351.html ,
// which just happened to be a simple example at the top of
// the Google heap for "jython swing simple".
//
import javax.swing.{ JButton => JSwJB };
class sbwob extends javax.swing.JFrame {
    var exitButton : JSwJB = _;
    var paintCalls = 0;
    var buttonPresses = 0;
    override def paint (g: java.awt.Graphics) = {
        paintCalls = paintCalls + 1;
        Console.println( "sbwob paint calls " + this.paintCalls );
        g.setColor(java.awt.Color.black);
        g.drawString("hello", 10, 10);
        g.fillOval(10, 10, 100, 100);
    }
    def mkExitButton = exitButton = new JSwJB( "Get me Out" );
    def init = {
        Console.println( "sbwob frame thing" );
        this.setTitle( "sbwob frame thing" );
        this.setSize(256, 256);
        mkExitButton;
        exitButton.addActionListener(goAway());
        this.getContentPane().add( exitButton );
    }
    // Inner class to handle button presses
    //   Will exit only after 6 or more repaints.
    case class goAway with java.awt.event.ActionListener {
        def actionPerformed ( e: java.awt.event.ActionEvent ) = {
            buttonPresses = buttonPresses + 1;
            if( sbwob.this.paintCalls > 5 ) {
                Console.println( "Button pressed " +
                    sbwob.this.buttonPresses + " times.  Exiting." );
                System.exit(0);
            }
        }
    }
}
object sbw_main {
    def main ( args : Array[String] ) = {
        var myhr = new sbwob;
        myhr.init;
        myhr.setVisible(true);
        Thread.sleep(20000);
        /*
        catch {
            // How can I catch just the InterruptedException?
            case Throwable =>
                Console.println( "20-second sleep interrupted." );
        }
        */
        var m: String =
            if( myhr.buttonPresses == 0 ) "No button pressed.";
            else   "Button pressed " + myhr.buttonPresses +
                   " times.  Exiting.";
        Console.println( m + "  Ran out of patience." );
        System.exit( 0 );
    }
}

Updated: I removed all of the blank lines because Radio's renderer insists on putting three blank lines wherever I had a single blank line. Yecch. So I made a directory to hold the examples I come up with as I learn the language. It is here: http://dal.i.am/sw/scala-ex/ and this particular example is http://dal.i.am/sw/scala-ex/sbw_db8.scala

Further update: the comment at the start had the wrong message number from the e-lang list. Fixed now.
12:43:32 AM comment/