class ToolbarHooks

class ToolbarHooks {
    
    /**
     * Implements hook_help().
     */
    public function help($route_name, RouteMatchInterface $route_match) {
        switch ($route_name) {
            case 'help.page.toolbar':
                $output = '<h2>' . t('About') . '</h2>';
                $output .= '<p>' . t('The Toolbar module provides a toolbar for site administrators, which displays tabs and trays provided by the Toolbar module itself and other modules. For more information, see the <a href=":toolbar_docs">online documentation for the Toolbar module</a>.', [
                    ':toolbar_docs' => 'https://www.drupal.org/docs/8/core/modules/toolbar',
                ]) . '</p>';
                $output .= '<h4>' . t('Terminology') . '</h4>';
                $output .= '<dl>';
                $output .= '<dt>' . t('Tabs') . '</dt>';
                $output .= '<dd>' . t('Tabs are buttons, displayed in a bar across the top of the screen. Some tabs execute an action (such as starting Edit mode), while other tabs toggle which tray is open.') . '</dd>';
                $output .= '<dt>' . t('Trays') . '</dt>';
                $output .= '<dd>' . t('Trays are usually lists of links, which can be hierarchical like a menu. If a tray has been toggled open, it is displayed either vertically or horizontally below the tab bar, depending on the browser width. Only one tray may be open at a time. If you click another tab, that tray will replace the tray being displayed. In wide browser widths, the user has the ability to toggle from vertical to horizontal, using a link at the bottom or right of the tray. Hierarchical menus only have open/close behavior in vertical mode; if you display a tray containing a hierarchical menu horizontally, only the top-level links will be available.') . '</dd>';
                $output .= '</dl>';
                return $output;
        }
    }
    
    /**
     * Implements hook_theme().
     */
    public function theme($existing, $type, $theme, $path) : array {
        $items['toolbar'] = [
            'render element' => 'element',
        ];
        $items['menu__toolbar'] = [
            'base hook' => 'menu',
            'variables' => [
                'menu_name' => NULL,
                'items' => [],
                'attributes' => [],
            ],
        ];
        return $items;
    }
    
    /**
     * Implements hook_page_top().
     *
     * Add admin toolbar to the top of the page automatically.
     */
    public function pageTop(array &$page_top) {
        $page_top['toolbar'] = [
            '#type' => 'toolbar',
            '#access' => \Drupal::currentUser()->hasPermission('access toolbar'),
            '#cache' => [
                'keys' => [
                    'toolbar',
                ],
                'contexts' => [
                    'user.permissions',
                ],
            ],
        ];
    }
    
    /**
     * Implements hook_toolbar().
     */
    public function toolbar() {
        // The 'Home' tab is a simple link, with no corresponding tray.
        $items['home'] = [
            '#type' => 'toolbar_item',
            'tab' => [
                '#type' => 'link',
                '#title' => t('Back to site'),
                '#url' => Url::fromRoute('<front>'),
                '#attributes' => [
                    'title' => t('Return to site content'),
                    'class' => [
                        'toolbar-icon',
                        'toolbar-icon-escape-admin',
                    ],
                    'data-toolbar-escape-admin' => TRUE,
                ],
            ],
            '#wrapper_attributes' => [
                'class' => [
                    'home-toolbar-tab',
                ],
            ],
            '#attached' => [
                'library' => [
                    'toolbar/toolbar.escapeAdmin',
                ],
            ],
            '#weight' => -20,
        ];
        // To conserve bandwidth, we only include the top-level links in the HTML.
        // The subtrees are fetched through a JSONP script that is generated at the
        // toolbar_subtrees route. We provide the JavaScript requesting that JSONP
        // script here with the hash parameter that is needed for that route.
        // @see toolbar_subtrees_jsonp()
        [
            $hash,
            $hash_cacheability,
        ] = _toolbar_get_subtrees_hash();
        $subtrees_attached['drupalSettings']['toolbar'] = [
            'subtreesHash' => $hash,
        ];
        // The administration element has a link that is themed to correspond to
        // a toolbar tray. The tray contains the full administrative menu of the site.
        $items['administration'] = [
            '#type' => 'toolbar_item',
            'tab' => [
                '#type' => 'link',
                '#title' => t('Manage'),
                '#url' => Url::fromRoute('system.admin'),
                '#attributes' => [
                    'title' => t('Admin menu'),
                    'class' => [
                        'toolbar-icon',
                        'toolbar-icon-menu',
                    ],
                    // A data attribute that indicates to the client to defer loading of
                    // the admin menu subtrees until this tab is activated. Admin menu
                    // subtrees will not render to the DOM if this attribute is removed.
                    // The value of the attribute is intentionally left blank. Only the
                    // presence of the attribute is necessary.
'data-drupal-subtrees' => '',
                ],
            ],
            'tray' => [
                '#heading' => t('Administration menu'),
                '#attached' => $subtrees_attached,
                'toolbar_administration' => [
                    '#pre_render' => [
                        [
                            ToolbarController::class,
                            'preRenderAdministrationTray',
                        ],
                    ],
                    '#type' => 'container',
                    '#attributes' => [
                        'class' => [
                            'toolbar-menu-administration',
                        ],
                    ],
                ],
            ],
            '#weight' => -15,
        ];
        $hash_cacheability->applyTo($items['administration']);
        return $items;
    }

}