class RetinaHelper {
 
   /**
    * Returns true if the device is a retina device
    * 
    **/
 
   function is_retina_device() 
   {
      // Check if a cookie is set
      $cookie_value = false;
      if (isset($_COOKIE['devicePixelRatio'])) {
         $cookie_value = intval($_COOKIE['devicePixelRatio']);
      }
 
      // Check if DPR is high enough to warrant retina image
      if ($cookie_value !== false && $cookie_value > 1) {
         // Check if retina image exists
         return true;
      }
 
      else {
         return false;
      }
   }
 
 
}
 

 
<?php 
defined('C5_EXECUTE') or die("Access Denied.");
$rssUrl = $showRss ? $controller->getRssUrl($b) : '';
$th = Loader::helper('text');
$rth = Loader::helper('retina'); // Load retina helper
$ih = Loader::helper('image'); //<--uncomment this line if displaying image attributes (see below)
//Note that $nh (navigation helper) is already loaded for us by the controller (for legacy reasons)
?>
 
<div class="ccm-page-list">
 
   <?php  foreach ($pages as $page):
 
      // Prepare data for each page being listed...
      $title = $th->entities($page->getCollectionName());
      $url = $nh->getLinkToCollection($page);
      $target = ($page->getCollectionPointerExternalLink() != '' && $page->openCollectionPointerExternalLinkInNewWindow()) ? '_blank' : $page->getAttribute('nav_target');
      $target = empty($target) ? '_self' : $target;
      $description = $page->getCollectionDescription();
      $description = $controller->truncateSummaries ? $th->shorten($description, $controller->truncateChars) : $description;
      $description = $th->entities($description);   
 
      //Other useful page data...
      //$date = date('F j, Y', strtotime($page->getCollectionDatePublic()));
      //$last_edited_by = $page->getVersionObject()->getVersionAuthorUserName();
      //$original_author = Page::getByID($page->getCollectionID(), 1)->getVersionObject()->getVersionAuthorUserName();
 
      /* CUSTOM ATTRIBUTE EXAMPLES:
       * $example_value = $page->getAttribute('example_attribute_handle');
       *
       * HOW TO USE IMAGE ATTRIBUTES:
       * 1) Uncomment the "$ih = Loader::helper('image');" line up top.
       * 2) Put in some code here like the following 2 lines:
       *      $img = $page->getAttribute('example_image_attribute_handle');
       *      $thumb = $ih->getThumbnail($img, 64, 9999, false);
       *    (Replace "64" with max width, "9999" with max height. The "9999" effectively means "no maximum size" for that particular dimension.)
       *    (Change the last argument from false to true if you want thumbnails cropped.)
       * 3) Output the image tag below like this:
       *      <img src="<?php  echo $thumb->src ?>" width="<?php  echo $thumb->width ?>" height="<?php  echo $thumb->height ?>" alt="" />
       *
       * ~OR~ IF YOU DO NOT WANT IMAGES TO BE RESIZED:
       * 1) Put in some code here like the following 2 lines:
       *        $img_src = $img->getRelativePath();
       *        list($img_width, $img_height) = getimagesize($img->getPath());
       * 2) Output the image tag below like this:
       *        <img src="<?php  echo $img_src ?>" width="<?php  echo $img_width ?>" height="<?php  echo $img_height ?>" alt="" />
       */
 
      /* End data preparation. */
 
      ?>
      <div class="col3">
 
      <h3 class="ccm-page-list-title">
         <a href="<?php  echo $url ?>" target="<?php  echo $target ?>"><?php  echo $title ?></a>
      </h3>
 
      <?
       // Load retina ready image from the attr
       $img = $page->getAttribute('thumbnail');
 
       // Not a retina device? Make a thumbnail
       if($rth->is_retina_device()==false)
       {
          $thumb = $ih->getThumbnail($img, 309, 9999, false);
          echo '<img src="'.$thumb->src.'" alt="" />';
       }
       // Retina device? Serve the original file
       else
       {
          $img_src = $img->getRelativePath();
          list($img_width, $img_height) = getimagesize($img->getPath());
          echo '<img src="'.$img_src.'" alt="" />';
       }
 
      /* The HTML from here through "endforeach" is repeated for every item in the list... */ ?>
 
      <div class="ccm-page-list-description">
         <?php  echo $description ?>
      </div>
 
      </div>
 
   <?php  endforeach; ?>
 
 
   <?php  if ($showRss): ?>
      <div class="ccm-page-list-rss-icon">
         <a href="<?php  echo $rssUrl ?>" target="_blank"><img src="<?php  echo $rssIconSrc ?>" width="14" height="14" alt="<?php  echo t('RSS Icon') ?>" title="<?php  echo t('RSS Feed') ?>" /></a>
      </div>
      <link href="<?php  echo BASE_URL.$rssUrl ?>" rel="alternate" type="application/rss+xml" title="<?php  echo $rssTitle; ?>" />
   <?php  endif; ?>
 
</div><!-- end .ccm-page-list -->
 
 
<?php  if ($showPagination): ?>
   <div id="pagination">
      <div class="ccm-spacer"></div>
      <div class="ccm-pagination">
         <span class="ccm-page-left"><?php  echo $paginator->getPrevious('« ' . t('Previous')) ?></span>
         <?php  echo $paginator->getPages() ?>
         <span class="ccm-page-right"><?php  echo $paginator->getNext(t('Next') . ' »') ?></span>
      </div>
   </div>
<?php  endif; ?>