MDL-70196 theme_boost: New navbar renderer for navbar alterations

- Part of: MDL-69588

theme/boost/classes/boostnavbar.php

@@ -0,0 +1,179 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace theme_boost;
+
+/**
+ * Creates a navbar for boost that allows easy control of the navbar items.
+ *
+ * @package    theme_boost
+ * @copyright  2021 Adrian Greeve <adrian@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class boostnavbar implements \renderable {
+
+    /** @var array The individual items of the navbar. */
+    protected $items = [];
+
+    /**
+     * Takes a navbar object and picks the necessary parts for display.
+     *
+     * @param \navbar $navbar The navigation bar.
+     */
+    public function __construct(\navbar $navbar) {
+        foreach ($navbar->get_items() as $item) {
+            $this->items[] = $item;
+        }
+        $this->prepare_nodes_for_boost();
+    }
+
+    /**
+     * Prepares the navigation nodes for use with boost.
+     */
+    protected function prepare_nodes_for_boost(): void {
+        // Don't display the navbar if we are in the site navigation.
+        if (!is_null($this->get_item('root'))) {
+            $this->clear_items();
+            return;
+        }
+
+        $this->remove('myhome'); // Dashboard.
+        $this->remove('home');
+
+        // Set the designated one path for courses.
+        $mycoursesnode = $this->get_item('mycourses');
+        if (!is_null($mycoursesnode)) {
+            $url = new \moodle_url('/mycourses/');
+            $mycoursesnode->action = $url;
+            $mycoursesnode->text = get_string('courses');
+        }
+
+        $this->remove_no_link_items();
+
+        // Don't display the navbar if there is only one item. Apparently this is bad UX design.
+        if ($this->item_count() <= 1) {
+            $this->clear_items();
+            return;
+        }
+
+        // Make sure that the last item is not a link. Not sure if this is always a good idea.
+        $this->remove_last_item_action();
+    }
+
+    /**
+     * Get all the boostnavbaritem elements.
+     *
+     * @return boostnavbaritem[] Boost navbar items.
+     */
+    public function get_items(): array {
+        return $this->items;
+    }
+
+    /**
+     * Removes all navigation items out of this boost navbar
+     */
+    protected function clear_items(): void {
+        $this->items = [];
+    }
+
+    /**
+     * Retrieve a single navbar item.
+     *
+     * @param  string|int $key The identifier of the navbar item to return.
+     * @return \breadcrumb_navigation_node|null The navbar item.
+     */
+    protected function get_item($key): ?\breadcrumb_navigation_node {
+        foreach ($this->items as $item) {
+            if ($key === $item->key) {
+                return $item;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Counts all of the navbar items.
+     *
+     * @return int How many navbar items there are.
+     */
+    protected function item_count(): int {
+        return count($this->items);
+    }
+
+    /**
+     * Remove a boostnavbaritem from the boost navbar.
+     *
+     * @param  string|int $itemkey An identifier for the boostnavbaritem
+     */
+    protected function remove($itemkey): void {
+
+        $itemfound = false;
+        foreach ($this->items as $key => $item) {
+            if ($item->key === $itemkey) {
+                unset($this->items[$key]);
+                $itemfound = true;
+                break;
+            }
+        }
+        if (!$itemfound) {
+            return;
+        }
+
+        $itemcount = $this->item_count();
+        if ($itemcount <= 0) {
+            return;
+        }
+
+        $this->items = array_values($this->items);
+        // Set the last item to last item if it is not.
+        $lastitem = $this->items[$itemcount - 1];
+        if (!$lastitem->is_last()) {
+            $lastitem->set_last(true);
+        }
+    }
+
+    /**
+     * Removes the action from the last item of the boostnavbaritem.
+     */
+    protected function remove_last_item_action(): void {
+        $item = end($this->items);
+        $item->action = null;
+        reset($this->items);
+    }
+
+    /**
+     * Returns the second last navbar item. This is for use in the mobile view where we are showing just the second
+     * last item in the breadcrumb navbar.
+     *
+     * @return breakcrumb_navigation_node|null The second last navigation node.
+     */
+    public function get_penultimate_item(): ?\breadcrumb_navigation_node {
+        $number = $this->item_count() - 2;
+        return ($number >= 0) ? $this->items[$number] : null;
+    }
+
+    /**
+     * Remove items that are categories or have no actions associated with them.
+     */
+    protected function remove_no_link_items(): void {
+        foreach ($this->items as $key => $value) {
+            if (!$value->has_action() || $value->type == \navigation_node::TYPE_SECTION) {
+                unset($this->items[$key]);
+            }
+        }
+        $this->items = array_values($this->items);
+    }
+}

theme/boost/classes/output/core_renderer.php

@@ -42,4 +42,13 @@ class core_renderer extends \core_renderer {
         return $this->render_single_button($button);
     }
 
+    /**
+     * Renders the "breadcrumb" for all pages in boost.
+     *
+     * @return string the HTML for the navbar.
+     */
+    public function navbar(): string {
+        $newnav = new \theme_boost\boostnavbar($this->page->navbar);
+        return $this->render_from_template('core/navbar', $newnav);
+    }
 }

theme/boost/version.php

@@ -24,6 +24,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2021052500;
+$plugin->version   = 2021052503;
 $plugin->requires  = 2021052500;
 $plugin->component = 'theme_boost';