title: setDisplayHomeAsUpEnabled() + Up Arrow?
body: <p>We can use the <code>setDisplayHomeAsUpEnabled()</code> method on an activity to display the "up" arrow on the action bar.</p>
  
  <p>If I understand correctly, we're only really supposed to show the up arrow if we're not the root activity.</p>
  
  <p>Clicking the "up" arrow should take us to the root activity. Is that all there is to it? I should then add this call to all my activities like so:</p>
  
  <pre><code>class RootActivity {
      public void onCreate() {
          setDisplayHomeAsUpEnabled(false);
      }
  }
  
  class AppleActivity {
      public void onCreate() {
          setDisplayHomeAsUpEnabled(true);
      }
  }
  
  class OrangeActivity {
      public void onCreate() {
          setDisplayHomeAsUpEnabled(true);
      }
  }
  
  ...
  </code></pre>