title: 3-pane looping scrolling panel -- suggestions
body: <p>I have a UI implementation challenge (at least for me). The desire is for a scrolling view of 3 panes that loops endlessly: when the user swipes right from pane2 to pane3, they should be able to keep scrolling right to pane1 and on through the panes, repeating endlessly. One and only one full pane is shown at a time--there's no hanging edge.</p>
  
  <p>Something like this:
  <img src="https://i.stack.imgur.com/K8w9F.png" alt="3 pane panorama"></p>
  
  <p>All the examples I've found are very elaborate, with databinding and viewmodels, generally based on ListBoxes/views. We don't need anything that sophisticated: our 3 panes aren't dynamic and there are always 3.</p>
  
  <p>Our current implementation, which scrolls only back and forth between pane1 and pane3 (which met the previous requirement), follows the MSDN WinRT controls example:</p>
  
  <pre><code>&lt;ScrollViewer&gt;
    &lt;StackPanel&gt;
      &lt;Grid /&gt; &lt;!-- pane1 --&gt;
      &lt;Grid /&gt; &lt;!-- pane2 --&gt;
      &lt;Grid /&gt; &lt;!-- pane3 --&gt;
    &lt;/StackPanel&gt;
  &lt;/ScrollViewer&gt;
  </code></pre>
  
  <p>This works fine so far as it goes, as we have the touch experience, and the content follows the user's finger and is visible while they scroll.</p>
  
  <p>My thinking so far is:</p>
  
  <ul>
  <li>add another grid on the 'start' and 'end'  </li>
  <li>figuring out the horizontal offset while scrolling</li>
  <li>once halfway through a panel, copy/insert the 'last' pane contents into the 'next' pane</li>
  </ul>
  
  <p>But I don't know if this will work, and overall am not sure how to go about it. We are looking for something very simple just to get the point across and for usability testing, but it must really work in C#/XAML (a Windows Store app). So I am asking wiser people for suggestions. </p>