/**
 * Implements hook_block_list_alter().
 */
function {{ machine_name }}_block_list_alter(&$blocks) {
  global $language, $theme_key;

  // This example shows how to achieve language specific visibility setting for
  // blocks.

  $result = db_query('SELECT module, delta, language FROM {my_table}');
  $block_languages = array();
  foreach ($result as $record) {
    $block_languages[$record->module][$record->delta][$record->language] = TRUE;
  }

  foreach ($blocks as $key => $block) {
    // Any module using this alter should inspect the data before changing it,
    // to ensure it is what they expect.
    if (!isset($block->theme) || !isset($block->status) || $block->theme != $theme_key || $block->status != 1) {
      // This block was added by a contrib module, leave it in the list.
      continue;
    }

    if (!isset($block_languages[$block->module][$block->delta])) {
      // No language setting for this block, leave it in the list.
      continue;
    }

    if (!isset($block_languages[$block->module][$block->delta][$language->language])) {
      // This block should not be displayed with the active language, remove
      // from the list.
      unset($blocks[$key]);
    }
  }
}