Pager toolbar in custom module in magento - magento

Question

I use this tutorial and display products on the basis of multiple categories but now I am getting in issue is that the pager tool bar not working on that.
My block code is :
<reference name="content">
<block name="mymodule" type="mymodule/product_listcategories" template="catalog/product/list.phtml">
<action method="setCategories">
<ids>2,3,4</ids>
</action>
</block>
</reference>
I also add this code with above
<block type="catalog/product_list_toolbar" name="product_list_toolbar" template="catalog/product/list/toolbar.phtml">
<block type="page/html_pager" name="product_list_toolbar_pager"/>
</block>
<action method="setToolbarBlockName"><name>product_list_toolbar</name></action>
</block>
It display toolbar but the toolbar is not working (limit,orderby).
My block code is
class Mymodule_Block_Product_Listcategories extends Mage_Catalog_Block_Product_List
{
protected function _getProductCollection()
{
$this->_productCollection = Mage::getModel('catalog/product')->getCollection();
$this->_productCollection->addAttributeToSelect('*');
if($this->getCategories()!="")
$this->_productCollection->addCategoriesFilter($this->getCategories());
return $this->_productCollection;
}
}
}
Does anyone know where is the problem? I think I'm missing some code for the pager? Thanks in advance

Answer 1

After search so much i got a solution.I didn't know whether it right or wrong way but it solve my problem.On my block i create intance of
$cpBlock = $this->getLayout()->getBlockSingleton('Mage_Catalog_Block_Product_List_Toolbar');
and access the pager core function like $this->_itemPerPage = $cpBlock->getLimit(); .In the above code itemperpage is the total no of items to be displayed on listing page.This code work if you create custom module and extend you block from list block.Thanks