Display read only info on admin, custom post page

add_action( 'edit_form_after_title', 'my_edit_form_after_title');
function my_edit_form_after_title($post) {
  $post_types = array( 'page' ); // post type / s
  $templates = array( 'template-custom.php' ); // not edit :D
  if( !in_array( $post->post_type,         $post_types) ) return;
  if( !in_array( get_page_template_slug(), $templates) ) return;

  global $_wp_post_type_features;

  foreach ($post_types  as $post_type) {
    if( isset($_wp_post_type_features[ $post_type ]['editor']) ) {
       unset($_wp_post_type_features[ $post_type ]['editor']); // we remove the "editor" if supported in this post type
    }
  }

  ?><p><?php echo $post->post_content; ?></p><?php // custom print post_content :D 
}