change_field_collection_in_field_collection_image_style.php

<?php

/**
 * Implements hook_entity_view_alter()
 *
 * Task: change child field_collection view mode depending on parent 
 *       field_block_layout value
 *
 * Solution: Screw that. Instead change the image style for 
 *   field_collection_imagecaption in the field_collection_content_block 
 *   when the layout is two columns.
 *
 * Notes: ds_get_field_settings() does not work. The child field_collection 
 *   fields view_modes need to be changed to the new view mode settings 
 *   in order for the whole thing to work. In our case, the image style is most
 *   important, so... will have to hard-coded it. :/
 */
function theming_fixes_entity_view_alter(&$build, $type) {
  if ($build['#bundle'] != 'field_collection_content_block') {
    return;
  }

  $entity = &$build['#entity'];
  $layout = $entity->field_block_layout[LANGUAGE_NONE][0]['value'];

  if (!in_array($layout, array('half-width-left', 'half-width-right'))) {
    return;
  }

  foreach ($build as $key => &$field) {
    if (strpos($key, 'field_collection') === FALSE) {
      continue;
    }

    foreach ($field['#items'] as $index => $collection_item) {
      $id = $collection_item['value'];
      $item = &$field[$index]['entity']['field_collection_item'][$id];

      if ($item['#bundle'] == 'field_collection_imagecaption') {
        $image = &$item['field_image_main'];
        $image['#view_mode'] = 'two_column_content';
        foreach(array_keys($image['#items']) as $image_index) {
          $image[$image_index]['#image_style'] = 'half_page_width_345px';
        }
      }
    }
  }
}