This may have been hidden somewhere in the docs, but I don’t remember seeing it:
Assuming everything is running on the same thread, would an activity callback, or any kind of callback for that matter, interrupt a runnable , or even some other callback, executing on the thread, or are they posted sequentially by time of occurance as messages similar to runnables?
It certainly doesn’t interrupt execution, at least in the UI thread. For instance, say that you have a Button, and you place a Thread.sleep(10000) in its onClick callback. Well, as soon as you press the button the entire UI will freeze. This wouldn’t happen if the onClick callback interrupted the UI thread’s execution.