feat: show toc on mobile screens (#1964)

_javascript/modules/components/toc.js

@@ -1,15 +1,30 @@
-export function toc() {
-  if (document.querySelector('main h2, main h3')) {
-    // see: https://github.com/tscanlin/tocbot#usage
-    tocbot.init({
-      tocSelector: '#toc',
-      contentSelector: '.content',
-      ignoreSelector: '[data-toc-skip]',
-      headingSelector: 'h2, h3, h4',
-      orderedList: false,
-      scrollSmooth: false
-    });
+import { TocMobile as mobile } from './toc/toc-mobile';
+import { TocDesktop as desktop } from './toc/toc-desktop';
 
-    document.getElementById('toc-wrapper').classList.remove('d-none');
+const desktopMode = matchMedia('(min-width: 1200px)');
+
+function refresh(e) {
+  if (e.matches) {
+    mobile.hidePopup();
+    desktop.refresh();
+  } else {
+    mobile.refresh();
   }
 }
+
+function init() {
+  if (document.querySelector('main>article[data-toc="true"]') === null) {
+    return;
+  }
+
+  // Avoid create multiple instances of Tocbot. Ref: <https://github.com/tscanlin/tocbot/issues/203>
+  if (desktopMode.matches) {
+    desktop.init();
+  } else {
+    mobile.init();
+  }
+
+  desktopMode.onchange = refresh;
+}
+
+export { init as initToc };