protected void notifyCancelListeners() {
		Runnable r = () -> {
			for (CancelledListener mcl : listeners) {
				mcl.cancelled();
			}
		};
		Swing.runLater(r);
	}
Sets the visibility of the progress icon

@param visible if true, display the progress icon
Ghidra/Framework/Docking/src/main/java/ghidra/util/task/TaskMonitorComponent.java