fix: select active element in toc

Author: deemp

docs/theme/pagetoc.js

@@ -2,19 +2,16 @@ function forEach(elems, fun) {
   Array.prototype.forEach.call(elems, fun);
 }
 
+function getPagetocElems() {
+  return document.getElementsByClassName("pagetoc")[0].children;
+}
+
 // Un-active everything when you click it
 function forPagetocElem(fun) {
-  forEach(document.getElementsByClassName("pagetoc")[0].children, fun);
+  forEach(getPagetocElems(), fun);
 }
 
-forPagetocElem(function (el) {
-  el.addEventHandler("click", function () {
-    forPagetocElem(function (el) {
-      el.classList.remove("active");
-    });
-    el.classList.add("active");
-  });
-});
+var activeHref = location.href;
 
 function getRect(element) {
   return element.getBoundingClientRect();
@@ -30,11 +27,23 @@ function overflowBottom(container, element) {
 
 var updateFunction = function () {
   var id = undefined;
+
+  if (location.href != activeHref) {
+    activeHref = location.href;
+    forPagetocElem(function (el) {
+      if (el.href == activeHref) {
+        id = el;
+      }
+    });
+  }
+
   var elements = document.getElementsByClassName("header");
+  let menuBottom = getRect(document.getElementById("menu-bar")).bottom;
   let contentCenter = window.innerHeight / 2;
   let margin = contentCenter / 3;
+
   forEach(elements, function (el, i, arr) {
-    if (id === undefined && getRect(el).top >= contentCenter - margin) {
+    if (id === undefined && getRect(el).bottom >= menuBottom) {
       if (getRect(el).top >= contentCenter + margin) {
         id = arr[Math.max(0, i - 1)];
       } else {
@@ -48,6 +57,7 @@ var updateFunction = function () {
   });
 
   if (!id) return;
+
   forPagetocElem(function (el) {
     if (id.href.localeCompare(el.href) == 0) {
       el.classList.add("active");