Using region-odd and region-even

Carloyn:

This isn't something this module was designed to handle. You can achieve this at the theme layer using template_preprocess_block() to create a "counter" to track each block as it's themed.

Note that the blocks already contain a "zebra" value, which is added to the $variables array in Drupal core's implementation of template_preprocess_block() (same link as above). Here is the relevant code:

  static $block_counter = array();
  // All blocks get an independent counter for each region.
  if (!isset($block_counter[$variables['block']->region])) {
    $block_counter[$variables['block']->region] = 1;
  }
  // Same with zebra striping.
  $variables['block_zebra'] = ($block_counter[$variables['block']->region] % 2) ? 'odd' : 'even';
  $variables['block_id'] = $block_counter[$variables['block']->region]++;

The code above assigns a value of "odd" or "even" to $variables['block_zebra'], which can be accessed in the theme as $block_zebra. Try adding this line to your theme's block.tpl.php file(s) to see the output:

print $block_zebra;

More advanced stuff -- like multiple viewports and columns of blocks -- may require something more advanced than the "odd" or "even" classes inside $block_zebra. This will require some custom code in your theme.