code: private OnShowListener createOnShowListener() {
          return new OnShowListener() {
  
              @Override
              public void onShow(final DialogInterface dialog) {
                  decorator.showAnimated(getShowAnimation(), null);
  
                  if (onShowListener != null) {
                      onShowListener.onShow(dialog);
                  }
              }
  
          };
      }
docs: Creates and returns a listener, which allows to observe, when the dialog has been shown.
  
  @return The listener, which has been created, as an instance of the type {@link
  OnShowListener}