def METHOD_NAME(self, screen_id):
    if (screen_id >= 0):
        screen_size = self.slm.getScreenSize(screen_id)
        self.ui.screenLabel.setText("Displaying on screen " + str(screen_id + 1) + " (" + str(screen_size[0]) + " x " + str(screen_size[1]) + ")")
        self.ui.thumbnailWidget.setScreenSize(screen_size)
    else:
        self.ui.screenLabel.setText("Not displayed")
    # Reset to black.
    self.ui.patternComboBox.setCurrentIndex(0)