sub load_image {
   ...
   .... 
   .... 
    $vp->add( $image );

# add event watcher
   $image->signal_connect(
      event => sub {
         my ( $item, $event ) = @_;
         warn "event " . $event->type . "\n";
         return 0;    #return 1 prevents window from closing

# return 0 lets the signal thru
      }
   );
  ..... 
  .....
}