Add new custom post to query

Hi all, I have new trouble for custom post. I create new custom post is “ebookstore” and use pre_get_posts filter hook to add new custom post like code below:

// $this->type = "ebookstore"
if(!is_admin()){
                add_filter('pre_get_posts',array(&$this,'changes_query'));
            }
function changes_query($query){
            if(!is_admin()){
                $query->set('post_type',array($this->type,'post','page'));
            }

            return $query;
        }

And if i create a new custom post, i have to write more like this:

$query->set('post_type',array($this->type,'post','page','ebookstore'));

And if i create an additional 100 new postypes.I had to write how for this case.

Thank you