Updating GUI: Runnables vs Messages

I would say there is little difference between using a Message vs a Runnable. It’ll mostly boil down to personal preference. Why? Looking at the source code you’ll find that posting a Runnable uses the same exact messaging mechanism. It simply attaches the Runnable to a Message and sends that.

4.4.2 Source Code

public final boolean post(Runnable r) {
    return  sendMessageDelayed(getPostMessage(r), 0);
}

private static Message getPostMessage(Runnable r) {
    Message m = Message.obtain();
    m.callback = r;
    return m;
}

Ref: Grep Code – Handler