Merge 27a70e4c12 into 97ea67198b

Long sidebars did not scroll to show the selected entry. This made
working with such long sidebars quite confusing.

assets/js/sidebar.js

@@ -1,4 +1,9 @@
 document.addEventListener("DOMContentLoaded", function () {
+  scrollToActiveItem();
+  enableCollapsibles();
+});
+
+function enableCollapsibles() {
   const buttons = document.querySelectorAll(".hextra-sidebar-collapsible-button");
   buttons.forEach(function (button) {
     button.addEventListener("click", function (e) {
@@ -9,4 +14,23 @@ document.addEventListener("DOMContentLoaded", function () {
       }
     });
   });
-});
+}
+
+function scrollToActiveItem() {
+  const sidebarScrollbar = document.querySelector("aside.sidebar-container > .hextra-scrollbar");
+  const activeItems = document.querySelectorAll(".sidebar-active-item");
+  const visibleActiveItem = Array.from(activeItems).find(function (activeItem) {
+    return activeItem.getBoundingClientRect().height > 0;
+  });
+
+  if (!visibleActiveItem) {
+    return;
+  }
+
+  const yOffset = visibleActiveItem.clientHeight;
+  const yDistance = visibleActiveItem.getBoundingClientRect().top - sidebarScrollbar.getBoundingClientRect().top;
+  sidebarScrollbar.scrollTo({
+    behavior: "instant",
+    top: yDistance - yOffset
+  });
+}

layouts/partials/components/giscus.html

@@ -1,4 +1,26 @@
-{{- $lang := site.Language.LanguageCode | default `en` -}}
+{{ $default_chinese := "zh-CN" }}
+
+{{ $sl := site.Language }}
+{{ $giscus_lang := $sl.Lang | default `en` }}
+
+{{/* 
+  Special case for Chinese.
+  Giscus uses the geophraphical language code for these.
+  See: https://github.com/giscus/giscus/tree/main/locales
+  */}}
+{{ if eq $giscus_lang "zh" }}
+  {{/* Create a code formatted for Giscus: zh-CN or zn-TW. */}}
+  {{ $code := lower $sl.LanguageCode }}
+  
+  {{ if (hasSuffix $code "-cn") }}
+    {{ $giscus_lang = "zh-CN" }}
+  {{ else if (hasSuffix $code "-tw") }}
+    {{ $giscus_lang = "zh-TW" }}
+  {{ else }}
+    {{ $giscus_lang = $default_chinese }}
+  {{ end }}
+{{ end }}
+
 
 {{- with site.Params.comments.giscus -}}
 <script>
@@ -38,7 +60,7 @@
       "data-emit-metadata": "{{ (string .emitMetadata) | default 0 }}",
       "data-input-position": "{{ .inputPosition | default `top` }}",
       "data-theme": getGiscusTheme(),
-      "data-lang": "{{ .lang | default $lang }}",
+      "data-lang": "{{ .lang | default $giscus_lang }}",
       "crossorigin": "anonymous",
       "async": "",
     };