/**
  * Return the slide settings.
  *
  * @since 4.0.0
  * 
  * @return array The array of slide settings.
  */
 public static function getSlideSettings()
 {
     if (empty(self::$slide_settings)) {
         self::$slide_settings = array('content_type' => array('label' => __('Content Type', 'sliderpro'), 'type' => 'select', 'default_value' => 'custom', 'available_values' => array('custom' => __('Custom Content', 'sliderpro'), 'posts' => __('Content from posts', 'sliderpro'), 'gallery' => __('Images from post\'s gallery', 'sliderpro'), 'flickr' => __('Flickr images', 'sliderpro')), 'description' => ''), 'posts_post_types' => array('label' => __('Post Types', 'sliderpro'), 'type' => 'multiselect', 'default_value' => array('post'), 'description' => ''), 'posts_taxonomies' => array('label' => __('Taxonomies', 'sliderpro'), 'type' => 'multiselect', 'default_value' => array(), 'description' => ''), 'posts_relation' => array('label' => __('Match', 'sliderpro'), 'type' => 'select', 'default_value' => 'OR', 'available_values' => array('OR' => __('At least one', 'sliderpro'), 'AND' => __('All', 'sliderpro')), 'description' => ''), 'posts_operator' => array('label' => __('With selected', 'sliderpro'), 'type' => 'select', 'default_value' => 'IN', 'available_values' => array('IN' => __('Include', 'sliderpro'), 'NOT IN' => __('Exclude', 'sliderpro')), 'description' => ''), 'posts_order_by' => array('label' => __('Order By', 'sliderpro'), 'type' => 'select', 'default_value' => 'date', 'available_values' => array('date' => __('Date', 'sliderpro'), 'comment_count' => __('Comments', 'sliderpro'), 'title' => __('Title', 'sliderpro'), 'rand' => __('Random', 'sliderpro')), 'description' => ''), 'posts_order' => array('label' => __('Order', 'sliderpro'), 'type' => 'select', 'default_value' => 'DESC', 'available_values' => array('DESC' => __('Descending', 'sliderpro'), 'ASC' => __('Ascending', 'sliderpro')), 'description' => ''), 'posts_maximum' => array('label' => __('Limit', 'sliderpro'), 'type' => 'number', 'default_value' => 10, 'description' => ''), 'flickr_api_key' => array('label' => __('API Key', 'sliderpro'), 'type' => 'text', 'default_value' => '', 'description' => ''), 'flickr_load_by' => array('label' => __('Load By', 'sliderpro'), 'type' => 'select', 'default_value' => 'set_id', 'available_values' => array('set_id' => __('Set ID', 'sliderpro'), 'user_id' => __('User ID', 'sliderpro')), 'description' => ''), 'flickr_id' => array('label' => __('ID', 'sliderpro'), 'type' => 'text', 'default_value' => '', 'description' => ''), 'flickr_per_page' => array('label' => __('Limit', 'sliderpro'), 'type' => 'number', 'default_value' => 10, 'description' => ''));
         self::$slide_settings = apply_filters('sliderpro_default_slide_settings', self::$slide_settings);
     }
     return self::$slide_settings;
 }