[scala] Swing (event-thread) actors

[Victor Rodriguez]

Hello,

The subject of Scala actors that perform their body in the event
dispatch thread of Swing (AWT, really) has come up before, but
apparantely with no conclusion.

The following sketches a possible solution.  Will it work?  Or am I
missing something that makes this approach unworkable?

abstract class SwingActor extends Actor {
  override def react( f : PartialFunction[Any, Unit] ) : Nothing =
    super.react( new DispatchThreadPartialFunction( f ) )

  // need to override reactWithin, receive, receiveWithin..

  class DispatchThreadPartialFunction( f : PartialFunction[Any, Unit]
) extends PartialFunction[Any, Unit] {
    import java.awt.EventQueue

    def isDefinedAt( x : Any ) = f.isDefinedAt( x )

    def apply( x : Any ) : Unit =
      EventQueue.invokeLater {
        new Runnable() { def run() = f( x ) }
      }
  }
}


Best Regards,

Victor Rodriguez.

[Philipp Haller-2]

Hi Victor,

Victor Rodriguez wrote:
> The subject of Scala actors that perform their body in the event
> dispatch thread of Swing (AWT, really) has come up before, but
> apparantely with no conclusion.

With Scala 2.7.2 this is now very easy to do, thanks to overridable
schedulers:

  abstract class SwingActor extends Actor {
    override val scheduler = new SchedulerAdapter {
      def execute(fun: => Unit) {
        EventQueue.invokeLater {
          new Runnable() { def run() = fun }
        }
      }
    }
  }

Cheers,
Philipp