Only put the last visible TOC item as the tab stop.

The code to find the last item in the TOC to put in the tabbing order
was including items under collapsed subgroups.

This changes the list to only look at items visible in the sidebar.

chirun/themes/default/static/customisation.js

@@ -245,6 +245,27 @@ function treeview(element) {
         e.preventDefault();
     });
 
+    const all_items = [];
+
+    function get_children(el) {
+        const group = el.querySelector('[role="group"]');
+        return group ? group.children : [];
+    }
+
+    function find_all_items(el) {
+        const treeitem = el.querySelector('[role="treeitem"]');
+
+        all_items.push(treeitem);
+
+        if(treeitem.ariaExpanded == 'true') {
+            for(let child of get_children(el)) {
+                find_all_items(child);
+            }
+        }
+    }
+    find_all_items(element);
+
+
     element.addEventListener('keydown', e => {
         const modifier = e.altKey || e.ctrlKey || e.metaKey || e.shiftKey;
 
@@ -261,26 +282,6 @@ function treeview(element) {
         const siblings = Array.from(el.parentElement.children);
         const i = siblings.indexOf(el);
 
-        const all_items = [];
-
-        function find_all_items(el) {
-            const treeitem = el.querySelector('[role="treeitem"]');
-
-            all_items.push(treeitem);
-
-            if(treeitem.ariaExpanded == 'true') {
-                for(let child of get_children(el)) {
-                    find_all_items(child);
-                }
-            }
-        }
-        find_all_items(element);
-
-        function get_children(el) {
-            const group = el.querySelector('[role="group"]');
-            return group ? group.children : [];
-        }
-
         function next_item(el) {
             const treeitem = el.querySelector('[role="treeitem"]');
             const children = get_children(el);
@@ -469,7 +470,7 @@ function treeview(element) {
             }
         }
 
-        const visible_items = element.querySelectorAll('.visible[role="treeitem"]');
+        const visible_items = all_items.filter(item => item.classList.contains('visible'));
         if(visible_items.length) {
             visible_items[visible_items.length-1].tabIndex = 0;
         }