add default filter for admin grid magento2

Question

I have created the custom table to join sales_order_item and sales order grid. I need to display the order with complete status by default instead of pending status order.

I have searched for the same and got the solution for magento1, http://inchoo.net/magento/prepared-filter-for-magento-admin-grids/. Could anyone help me to implement the same filter by default on magento2

Now I am getting,

But I need to get complete status order details by default.

Answer 1

Finally, I got the output,

In my xml that defines the grid, I replaced Magento\Backend\Block\Widget\Grid as Test\Custom\Block\Adminhtml\Custom

In my Grid.php

namespace Test\Custom\Block\Adminhtml\Custom;
use Magento\Backend\Block\Widget\Grid as WidgetGrid;
class Grid extends WidgetGrid
    {
        protected function _construct()
        {
            parent::_construct();
            $this->setSaveParametersInSession(true);        
            //for default filter
            if ($this->hasData('default_filter')){
                $this->setDefaultFilter($this->getData('default_filter'));
            }
        }
        protected function _prepareCollection()
        {
            //on clicking reset filter on Grid it will make 'complete' status as default:
            if(!$this->getParam($this->getVarNameFilter(), null)) {
                $this->getCollection()->addFieldToFilter('salesGrid.status', array('eq' => 'complete'));
                $data['status'] = 'complete';           
                $this->_setFilterValues($data);
            }
            parent::_prepareCollection();
        }
    }