title: Correct way to start login activity
body: <p>I have an app that sometimes may require a login in the middle of execution, and I'm tyring to figure out how to pass around control.  There are quite a number of different things to do for authentication, so I have a utility class called Authenticator taking care of all that.</p>
  
  <p>In short, I want it so all activites in the app will be able to call some method like Authenticator.login() to present a login screen, and have Authenticator take care of everything.</p>
  
  <p>Here's what I've thought of so far for the login method:</p>
  
  <pre><code>public boolean login(Activity context)
  { 
      Intent intent = new Intent(context, Login.class);
      context.startActivityForResult(intent, LOGIN_ACTIVITY);
      return false;
  }
  </code></pre>
  
  <p>The problem I'm running into, though, is getting the result back from logging in.  I want to know if they pressed the cancel button or had an incorrect password BEFORE I pass control back to the Activity that called login().  </p>
  
  <p>There is the method onActivityResult(), but that is in class Activity, whereas Authenticator is not an activity.  Is there a way to start an activity for a result from inside a normal java class?</p>