title: What is the meaning of removeCallbacks(Runnable r) in Handler in Android
body: <p>I want to know what is the exact meaning of removeCallbacks(Runnable r) in Handler. I gone through its <a href="http://developer.android.com/reference/android/os/Handler.html#removeCallbacks%28java.lang.Runnable%29" rel="noreferrer">documentation</a> and it simply says "Remove any pending posts of Runnable r that are in the message queue".</p>
  
  <p>Now my question is if my message has already been started processing by my handler and in between if I call <code>removeCallbacks</code>, will it stop processing my half completed message? Or even if I call <code>removeCallbacks</code> the message which has already started processing by my handler (when I call <code>post(Runnable r)</code>) will be executed?</p>