void
ewl_widget_appearance_set(Ewl_Widget *w, char *appearance)
{
  DENTER_FUNCTION(DLEVEL_STABLE);
  DCHECK_PARAM_PTR("w", w);
  DCHECK_PARAM_PTR("appearance", appearance);
  DCHECK_TYPE("w", w, EWL_WIDGET_TYPE);
  
  /* make sure we have something to do */
  if (w->appearance && !strcmp(appearance, w->appearance))
    DLEAVE_FUNCTION(DLEVEL_STABLE);

  /*
   * The base appearance is used for determining the theme key of the
   * widget. Intentionally lose a reference to the ecore string to keep a
   * reference cached for later re-use.
   */
  w->appearance = ecore_string_instance(appearance);
  if (!w->appearance)
    DRETURN(DLEVEL_STABLE);

  /*
   * Recreate the visible components of the widget if necessary.
   */
  if (REALIZED(w)) {
    ewl_widget_unrealize(w);
    ewl_widget_realize(w);
  }

  DLEAVE_FUNCTION(DLEVEL_STABLE);
}