title: How to change a TextView's style at runtime
body: <p>I have an android app on which, when the user taps a <code>TextView</code>, I would like to apply a defined style.</p>
  
  <p>I thought to find a <code>textview.setStyle()</code> but it doesn't exists. I tried </p>
  
  <pre><code>textview.setTextAppearance();
  </code></pre>
  
  <p>but it does not work.</p>