View.php

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

/**
 * Adminhtml billing agreement view
 *
 * @api
 * @since 100.0.2
 */
class View extends \Magento\Backend\Block\Widget\Form\Container
{
    /**
     * Core registry
     *
     * @var \Magento\Framework\Registry
     */
    protected $_coreRegistry = null;

    /**
     * @param \Magento\Backend\Block\Widget\Context $context
     * @param \Magento\Framework\Registry $registry
     * @param array $data
     */
    public function __construct(
        \Magento\Backend\Block\Widget\Context $context,
        \Magento\Framework\Registry $registry,
        array $data = []
    ) {
        $this->_coreRegistry = $registry;
        parent::__construct($context, $data);
    }

    /**
     * Initialize view container
     *
     * @return void
     */
    protected function _construct()
    {
        $this->_objectId = 'agreement';
        $this->_controller = 'adminhtml_billing_agreement';
        $this->_mode = 'view';
        $this->_blockGroup = 'Magento_Paypal';

        parent::_construct();

        if (!$this->_isAllowed('Magento_Paypal::actions_manage')) {
            $this->buttonList->remove('delete');
        }
        $this->buttonList->remove('reset');
        $this->buttonList->remove('save');
        $this->setId('billing_agreement_view');

        $this->buttonList->add(
            'back',
            [
                'label' => __('Back'),
                'onclick' => 'setLocation(\'' . $this->getBackUrl() . '\')',
                'class' => 'back'
            ],
            -1
        );

        $agreement = $this->_getBillingAgreement();
        if ($agreement && $agreement->canCancel() && $this->_isAllowed('Magento_Paypal::actions_manage')) {
            $confirmText = __('Are you sure you want to do this?');
            $this->buttonList->add(
                'cancel',
                [
                    'label' => __('Cancel'),
                    'onclick' => "confirmSetLocation(" . "'{$confirmText}', '{$this->_getCancelUrl()}'" . ")",
                    'class' => 'cancel'
                ],
                -1
            );
        }
    }

    /**
     * Retrieve header text
     *
     * @return \Magento\Framework\Phrase
     */
    public function getHeaderText()
    {
        return __('Billing Agreement #%1', $this->_getBillingAgreement()->getReferenceId());
    }

    /**
     * Retrieve cancel billing agreement url
     *
     * @return string
     */
    protected function _getCancelUrl()
    {
        return $this->getUrl('*/*/cancel', ['agreement' => $this->_getBillingAgreement()->getAgreementId()]);
    }

    /**
     * Retrieve billing agreement model
     *
     * @return \Magento\Paypal\Model\Billing\Agreement
     */
    protected function _getBillingAgreement()
    {
        return $this->_coreRegistry->registry('current_billing_agreement');
    }

    /**
     * Check current user permissions for specified action
     *
     * @param string $resourceId
     * @return bool
     */
    protected function _isAllowed($resourceId)
    {
        return $this->_authorization->isAllowed($resourceId);
    }
}