title: How to hide layouts / views programmatically in Android
body: <p>I have just started learning Android. Few confusions I have regarding layouts in XML</p>
  
  <ol>
  <li><p>Are all views that I define in my layout are essentially inflated or they are optional? Suppose I have two different views in a view-group but I want to 
  use only first or only second conditionally. Is it possible?</p></li>
  <li><p>How dynamically created views deal with layout.XML
  file? </p></li>
  <li><p>If I want received messages to be shown in red and sent messages in black how can I do that?</p></li>
  </ol>