Return the path to the current themed element.
It can point to the active theme or the module handling a themed implementation. For example, when invoked within the scope of a theming call it will depend on where the theming function is handled. If implemented from a module, it will point to the module. If implemented from the active theme, it will point to the active theme. When called outside the scope of a theming call, it will always point to the active theme.
function path_to_theme() {
global $theme_path;
if (!isset($theme_path)) {
drupal_theme_initialize();
}
return $theme_path;
}