title: Calling methods on activity events
body: <p>I am writing a simple Android library. I have a couple of methods that I would like executed when certain activity events happen - like after activity got loaded or when the activity gets paused.</p>
  
  <p>One way I could think of was to create a class that extends activity, and write my methods there, and then have "target" activities extend that class. This was all methods get called</p>
  
  <p>But if the end user is extending some other activity already, this method won't work. Is there a better alternative?</p>