admin_post_thumbnail_size │ filter-hook │ WP 4.4.0

Filters the size used to display the post thumbnail image in the 'Featured image' meta box.

Note: When a theme adds 'post-thumbnail' support, a special 'post-thumbnail' image size is registered, which differs from the 'thumbnail' image size managed via the Settings > Media screen.

Usage

add_filter( 'admin_post_thumbnail_size', 'wp_kama_admin_post_thumbnail_size_filter', 10, 3 );

/**
 * Function for `admin_post_thumbnail_size` filter-hook.
 * 
 * @param string|int[] $size         Requested image size. Can be any registered image size name, or an array of width and height values in pixels (in that order).
 * @param int          $thumbnail_id Post thumbnail attachment ID.
 * @param WP_Post      $post         The post object associated with the thumbnail.
 *
 * @return string|int[]
 */
function wp_kama_admin_post_thumbnail_size_filter( $size, $thumbnail_id, $post ){

	// filter...
	return $size;
}

$size(string|int[])

Requested image size. Can be any registered image size name, or an array of width and height values in pixels (in that order).

$thumbnail_id(int)

Post thumbnail attachment ID.

$post(WP_Post)

The post object associated with the thumbnail.

Changelog

Where the hook is called

$size = apply_filters( 'admin_post_thumbnail_size', $size, $thumbnail_id, $post );

Where the hook is used in WordPress