Check listing belongs to which CPT in preview

I want to add it conditionally. Let me explain.
I have restaurant CPT and Hospital CPT.
I also have 2 different banner images uploaded to media: one for Restaurant and one for Hospital

Now, when user add new restaurant listing and doesn’t select any image file, I want to show banner image of restaurant. I think I can display it on page when it’s published, but I can’t find any code that let me know that this listing that is being added is of which post type so I can conditionally show it in preview mode. (i.e. in listing preview page)

Is there any such codes to know if new listing belong to which CPT without being published?

Hello Alex,
Thank you for your suggestion. However, I already did all of that. I wasn’t looking for all the options that were present. They could only work once the listing is published(or maybe only in my case, I don’t know). I was asking for code that will let me know that new listing belongs to which CPT type. Maybe I wasn’t able to clarity that before. However, I finally found it.

geodir_action_geodir_set_preview_post();

I used it in following way and solved what I was trying to achieve:

global $post, $preview;  
    if ( $preview ) {
        geodir_action_geodir_set_preview_post(); //sets $post value when previewing post
        $post_type = $post->listing_type; 
    } else { 
        $post_type = $post->post_type; 
    }

    if( $post_type == "gd_restaurant" ) {
        $postbanner_img_url = "$defult_url/wp-content/uploads/restaurant-banner.jpg"; //this way the image is displayed on restaurant listing page no matter the post status is
    }