title: make Android Textview or EditText selectable
body: <p>I want to make <code>EditText</code> or <code>Textview</code> selectable in my android project .
  project is for android 4.0+ . I add this : <code>txtView.setTextIsSelectable(true)</code> and also : <code>txtView.setCustomSelectionActionModeCallback(new myCallback());</code>
  to make my custom selection menu .
  but this error happend when i want to select the text .</p>
  
  <pre><code>W/TextView﹕ TextView does not support text selection. Action mode cancelled.
  </code></pre>
  
  <p>i searched about the error but didn't find the solution .what should i do ?</p>