Why should some methods be invoked only from the main application thread?
<p>I read about <a href="http://developer.android.com/reference/android/speech/SpeechRecognizer.html" rel="nofollow">this class</a>:</p>

<blockquote>
  <p>Do not instantiate this class directly, instead, call
  createSpeechRecognizer(Context). This class's methods must be invoked
  only from the main application thread.</p>
</blockquote>

<p>I suppose that the main application thread is the main Activity of an Android application...
Why should this class's methods be invoked only from the main application thread?</p>
