Creditmemo.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Sales\Block\Order;

use Magento\Customer\Model\Context;

/**
 * Sales order view block
 *
 * @api
 * @author      Magento Core Team <core@magentocommerce.com>
 * @since 100.0.2
 */
class Creditmemo extends \Magento\Sales\Block\Order\Creditmemo\Items
{
    /**
     * @var string
     */
    protected $_template = 'Magento_Sales::order/creditmemo.phtml';

    /**
     * @var \Magento\Framework\App\Http\Context
     */
    protected $httpContext;

    /**
     * @var \Magento\Payment\Helper\Data
     */
    protected $_paymentHelper;

    /**
     * @param \Magento\Framework\View\Element\Template\Context $context
     * @param \Magento\Framework\Registry $registry
     * @param \Magento\Framework\App\Http\Context $httpContext
     * @param \Magento\Payment\Helper\Data $paymentHelper
     * @param array $data
     */
    public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Magento\Framework\Registry $registry,
        \Magento\Framework\App\Http\Context $httpContext,
        \Magento\Payment\Helper\Data $paymentHelper,
        array $data = []
    ) {
        $this->_paymentHelper = $paymentHelper;
        $this->httpContext = $httpContext;
        parent::__construct($context, $registry, $data);
        $this->_isScopePrivate = true;
    }

    /**
     * @return void
     */
    protected function _prepareLayout()
    {
        $this->pageConfig->getTitle()->set(__('Order # %1', $this->getOrder()->getRealOrderId()));
        $infoBlock = $this->_paymentHelper->getInfoBlock($this->getOrder()->getPayment(), $this->getLayout());
        $this->setChild('payment_info', $infoBlock);
    }

    /**
     * @return string
     */
    public function getPaymentInfoHtml()
    {
        return $this->getChildHtml('payment_info');
    }

    /**
     * Retrieve current order model instance
     *
     * @return \Magento\Sales\Model\Order
     */
    public function getOrder()
    {
        return $this->_coreRegistry->registry('current_order');
    }

    /**
     * Return back url for logged in and guest users
     *
     * @return string
     */
    public function getBackUrl()
    {
        if ($this->httpContext->getValue(Context::CONTEXT_AUTH)) {
            return $this->getUrl('*/*/history');
        }
        return $this->getUrl('*/*/form');
    }

    /**
     * Return back title for logged in and guest users
     *
     * @return \Magento\Framework\Phrase
     */
    public function getBackTitle()
    {
        if ($this->httpContext->getValue(Context::CONTEXT_AUTH)) {
            return __('Back to My Orders');
        }
        return __('View Another Order');
    }

    /**
     * @param object $order
     * @return string
     */
    public function getInvoiceUrl($order)
    {
        return $this->getUrl('*/*/invoice', ['order_id' => $order->getId()]);
    }

    /**
     * @param object $order
     * @return string
     */
    public function getShipmentUrl($order)
    {
        return $this->getUrl('*/*/shipment', ['order_id' => $order->getId()]);
    }

    /**
     * @param object $order
     * @return string
     */
    public function getViewUrl($order)
    {
        return $this->getUrl('*/*/view', ['order_id' => $order->getId()]);
    }

    /**
     * @param object $creditmemo
     * @return string
     */
    public function getPrintCreditmemoUrl($creditmemo)
    {
        return $this->getUrl('*/*/printCreditmemo', ['creditmemo_id' => $creditmemo->getId()]);
    }

    /**
     * @param object $order
     * @return string
     */
    public function getPrintAllCreditmemosUrl($order)
    {
        return $this->getUrl('*/*/printCreditmemo', ['order_id' => $order->getId()]);
    }
}