title: How to get file read line by line
body: <p>I have a file containing text in separate line.<br>
  I want to display line first, and then if I press a button, the second line should be displayed in the <code>TextView</code> and the first line should disappear. Then, if I press it again, the third line should be displayed and so on.</p>
  
  <p>Should I have to use <code>TextSwitcher</code> or anything else? 
  How can I do that?</p>