Importing with a seperate thread

The class used:
    private class ProcessFile(filename : String) extends Runnable {

The function to do the work in a separate thread:
        private def importQuotes() {
            val quotesFile = QFileDialog.getOpenFileName(this, "Citaten bestand", QDir.currentPath())

            if (quotesFile != "") {
                val processFile = new ProcessFile(quotesFile)
                val runner      = new QThread(processFile)

                importButton.setEnabled(false)
                runner.finished.connect(this, "enableImport()")
                runner.start
            }
        }