Added support for focusable code blocks on overflow

material/assets/manifest.json

@@ -1,6 +1,6 @@
 {
-  "assets/javascripts/bundle.js": "assets/javascripts/bundle.4e2bfc5d.min.js",
-  "assets/javascripts/bundle.js.map": "assets/javascripts/bundle.4e2bfc5d.min.js.map",
+  "assets/javascripts/bundle.js": "assets/javascripts/bundle.ff925e8b.min.js",
+  "assets/javascripts/bundle.js.map": "assets/javascripts/bundle.ff925e8b.min.js.map",
   "assets/javascripts/vendor.js": "assets/javascripts/vendor.809e24aa.min.js",
   "assets/javascripts/vendor.js.map": "assets/javascripts/vendor.809e24aa.min.js.map",
   "assets/javascripts/worker/search.js": "assets/javascripts/worker/search.f6ebf1dc.min.js",

material/base.html

@@ -179,7 +179,7 @@
     </div>
     {% block scripts %}
       <script src="{{ 'assets/javascripts/vendor.809e24aa.min.js' | url }}"></script>
-      <script src="{{ 'assets/javascripts/bundle.4e2bfc5d.min.js' | url }}"></script>
+      <script src="{{ 'assets/javascripts/bundle.ff925e8b.min.js' | url }}"></script>
       {%- set translations = {} -%}
       {%- for key in [
         "clipboard.copy",

src/assets/javascripts/index.ts

@@ -86,6 +86,7 @@ import {
   SearchIndex
 } from "integrations"
 import {
+  patchCodeBlocks,
   patchTables,
   patchDetails,
   patchScrollfix,
@@ -178,6 +179,7 @@ export function initialize(config: unknown) {
 
   const keyboard$ = setupKeyboard()
 
+  patchCodeBlocks({ document$, viewport$ })
   patchDetails({ document$, hash$ })
   patchScripts({ document$ })
   patchSource({ document$ })

src/assets/javascripts/patches/code/index.ts

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2016-2020 Martin Donath <martin.donath@squidfunk.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+import { Observable, combineLatest } from "rxjs"
+import { distinctUntilKeyChanged, map } from "rxjs/operators"
+
+import { Viewport, getElements } from "browser"
+
+/* ----------------------------------------------------------------------------
+ * Helper types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Mount options
+ */
+interface MountOptions {
+  document$: Observable<Document>      /* Document observable */
+  viewport$: Observable<Viewport>      /* Viewport observable */
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Patch all `code` elements
+ *
+ * This function will make overflowing code blocks focusable via keyboard, so
+ * they can be scrolled without a mouse.
+ *
+ * @param options - Options
+ */
+export function patchCodeBlocks(
+  { document$, viewport$ }: MountOptions
+): void {
+  const els$ = document$
+    .pipe(
+      map(() => getElements<HTMLTableElement>("pre > code"))
+    )
+
+  /* Observe viewport size only */
+  const size$ = viewport$
+    .pipe(
+      distinctUntilKeyChanged("size")
+    )
+
+  /* Make overflowing elements focusable */
+  combineLatest([els$, size$])
+    .subscribe(([els]) => {
+      for (const el of els) {
+        if (el.scrollWidth > el.clientWidth)
+          el.setAttribute("tabindex", "0")
+        else
+          el.removeAttribute("tabindex")
+      }
+    })
+}

src/assets/javascripts/patches/index.ts

@@ -20,6 +20,7 @@
  * IN THE SOFTWARE.
  */
 
+export * from "./code"
 export * from "./details"
 export * from "./script"
 export * from "./scrollfix"