title: How can I slide a view in and out of a window in a Cocoa program
body: <p>I want to have a view on a window and in response to a message (button click or menu) I want to have another view slide down above it, and have the first view resize.</p>
  
  <p>I want to go from this:</p>
  
  <pre><code>**********************************
  *                                *
  *--------------------------------*
  *|                              |*
  *|        view 1                |*
  *|                              |*
  *--------------------------------*
  *                                *
  **********************************
  </code></pre>
  
  <p>to this:</p>
  
  <pre><code>**********************************
  *                                *
  *--------------------------------*
  *|        view 2                |*
  *--------------------------------*
  *--------------------------------*
  *|        view 1                |*
  *--------------------------------*
  *                                *
  **********************************
  </code></pre>
  
  <p>I'm not necessarily looking for code, an idea of where to start would be appreciated.</p>
  
  <p>This is for a desktop app.</p>