Discard all messages except the last one in a Scala actor - scala

Question

I have a SwingWorker actor which computes a plot for display from a parameters object it gets send; then draws the plot on the EDT thread. Some GUI elements can tweak parameters for this plot. When they change I generate a new parameter object and send it to the worker.
This works so far.
Now when moving a slider many events are created and queue up in the worker's mailbox. But I only need to compute the plot for the very last set of parameters. Is there a way to drop all messages from the inbox; keep the last one and process only that?
Currently the code looks like this
val worker = new SwingWorker {
def act() {
while (true) {
receive {
case params: ExperimentParameters => {
//somehow expensive
val result = RunExperiments.generateExperimentData(params)
Swing.onEDT{ GuiElement.redrawWith(result) }
}
}
}
}
}

Answer 1

Meanwhile I have found a solution. You can check the mailbox size of the actor and simply skip the message if it is not 0.
val worker = new SwingWorker {
def act() {
while (true) {
receive {
case params: ExperimentParameters => {
if( mailboxSize == 0) {
//somehow expensive
val result = RunExperiments.generateExperimentData(params)
Swing.onEDT{ GuiElement.redrawWith(result) }
}
}
}
}
}
}

Answer 2

Remember the last event without processing it, have a very short timeout, process the last event when you get the timeout
could look like (not tested)
while(true) {
var lastReceived : Option[ExperimentParameters] = None
receive {case params : ExperimentParameters => lastReceived = Some(params)}
while (!lastReceived.isEmpty) {
receiveWithin(0) {
case params: ExperimentParameters => lastReceived = Some(params)
case TIMEOUT => do your job with lastReceived.get;
}
}
}