What's Android Equivalent of iOS's Post Notification and Delegate function?
<p>I find the Post notification and delegate function are very useful in iOS.  Once I finish a task I can notify other piece of code to do something, I am sending out notices for others to do the work.</p>

<p>Post Notification is when you sending notice right away, whereas delegate is sometime down the line, it will send a notice.</p>

<p>In Android, I know there's event Listener, but that's only passive listening, what about me ctively sending notices. </p>

<p>Does Android has that in equivalent?</p>
