In order to fulfill,your require,
- Need to create a custom controller
- On dropdown changes,it will hit this controller's an action.
- On this action,the selected theme will be selected and back you last
page
If you want apply a theme to custom frontend ui then try this:
Mage::getSingleton('core/design_package')
->setPackageName($package)
->setTheme($theme);
This concept is like currency change.
controller code seems to like :
<?php
class Amit_Custommodule_IndexController extends Mage_Core_Controller_Front_Action{
public function indexAction(){
$package=$this->getRequest()->getParam('package');
$theme=$this->getRequest()->getParam('theme');
Mage::getSingleton('core/design_package')
->setPackageName($package)
->setTheme($theme);
// this code is redirec to you last page/same page
$this->_redirectUrl($this->_getRefererUrl());
}
}