hash link highlighting & additional skippers

7 files changed, 266 insertions, 69 deletions

diff --git a/src/misc-templates.js b/src/misc-templates.js
index 1c6dda55..db97e536 100644
--- a/src/misc-templates.js
+++ b/src/misc-templates.js
@@ -916,6 +916,21 @@ function unbound_generateNavigationLinks(current, {
 
 // Sticky heading, ooooo
 
+function unbound_generateContentHeading({
+  html,
+
+  id,
+  title,
+}) {
+  return html.tag('p',
+    {
+      class: 'content-heading',
+      id,
+      tabindex: '0',
+    },
+    title);
+}
+
 function unbound_generateStickyHeadingContainer({
   getRevealStringFromArtTags,
   html,
@@ -1025,6 +1040,7 @@ export {
   unbound_generateInfoGalleryLinks as generateInfoGalleryLinks,
   unbound_generateNavigationLinks as generateNavigationLinks,
 
+  unbound_generateContentHeading as generateContentHeading,
   unbound_generateStickyHeadingContainer as generateStickyHeadingContainer,
 
   unbound_getFooterLocalizationLinks as getFooterLocalizationLinks,
diff --git a/src/page/track.js b/src/page/track.js
index b9038bac..7f0d1cf2 100644
--- a/src/page/track.js
+++ b/src/page/track.js
@@ -170,6 +170,7 @@ export function write(track, {wikiData}) {
       generateAdditionalFilesList,
       generateAdditionalFilesShortcut,
       generateChronologyLinks,
+      generateContentHeading,
       generateNavigationLinks,
       generateTrackListDividedByGroups,
       getAlbumStylesheet,
@@ -324,8 +325,10 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               !empty(otherReleases) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.alsoReleasedAs')),
+                generateContentHeading({
+                  id: 'also-released-as',
+                  title: language.$('releaseInfo.alsoReleasedAs'),
+                }),
 
                 html.tag('ul', otherReleases.map(track =>
                   html.tag('li', language.$('releaseInfo.alsoReleasedAs.item', {
@@ -336,8 +339,10 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               !empty(contributorContribs) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.contributors')),
+                generateContentHeading({
+                  id: 'contributors',
+                  title: language.$('releaseInfo.contributors'),
+                }),
 
                 html.tag('ul', contributorContribs.map(contrib =>
                   html.tag('li', getArtistString([contrib], {
@@ -348,20 +353,26 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               !empty(referencedTracks) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.tracksReferenced', {
-                    track: html.tag('i', track.name),
-                  })),
+                generateContentHeading({
+                  id: 'references',
+                  title:
+                    language.$('releaseInfo.tracksReferenced', {
+                      track: html.tag('i', track.name),
+                    }),
+                }),
 
                 html.tag('ul', referencedTracks.map(getTrackItem)),
               ]),
 
             ...html.fragment(
               !empty(referencedByTracks) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.tracksThatReference', {
-                    track: html.tag('i', track.name),
-                  })),
+                generateContentHeading({
+                  id: 'referenced-by',
+                  title:
+                    language.$('releaseInfo.tracksThatReference', {
+                      track: html.tag('i', track.name),
+                    }),
+                }),
 
                 generateTrackListDividedByGroups(referencedByTracks, {
                   getTrackItem,
@@ -371,20 +382,26 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               !empty(sampledTracks) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.tracksSampled', {
-                    track: html.tag('i', track.name),
-                  })),
+                generateContentHeading({
+                  id: 'samples',
+                  title:
+                    language.$('releaseInfo.tracksSampled', {
+                      track: html.tag('i', track.name),
+                    }),
+                }),
 
                 html.tag('ul', sampledTracks.map(getTrackItem)),
               ]),
 
             ...html.fragment(
               !empty(sampledByTracks) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.tracksThatSample', {
-                    track: html.tag('i', track.name),
-                  })),
+                generateContentHeading({
+                  id: 'sampled-by',
+                  title:
+                    language.$('releaseInfo.tracksThatSample', {
+                      track: html.tag('i', track.name),
+                    })
+                }),
 
                 html.tag('ul', sampledByTracks.map(getTrackItem)),
               ]),
@@ -392,10 +409,13 @@ export function write(track, {wikiData}) {
             ...html.fragment(
               wikiInfo.enableFlashesAndGames &&
               !empty(flashesThatFeature) && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.flashesThatFeature', {
-                    track: html.tag('i', track.name),
-                  })),
+                generateContentHeading({
+                  id: 'featured-in',
+                  title:
+                    language.$('releaseInfo.flashesThatFeature', {
+                      track: html.tag('i', track.name),
+                    }),
+                }),
 
                 html.tag('ul', flashesThatFeature.map(({flash, as}) =>
                   html.tag('li',
@@ -412,17 +432,20 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               track.lyrics && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.lyrics')),
+                generateContentHeading({
+                  id: 'lyrics',
+                  title: language.$('releaseInfo.lyrics'),
+                }),
 
                 html.tag('blockquote', transformLyrics(track.lyrics)),
               ]),
 
             ...html.fragment(
               hasSheetMusicFiles && [
-                html.tag('p',
-                  {id: 'sheet-music-files', class: ['content-heading']},
-                  language.$('releaseInfo.sheetMusicFiles.heading')),
+                generateContentHeading({
+                  id: 'sheet-music-files',
+                  title: language.$('releaseInfo.sheetMusicFiles.heading'),
+                }),
 
                 generateAlbumAdditionalFilesList(album, track.sheetMusicFiles, {
                   fileSize: false,
@@ -431,30 +454,34 @@ export function write(track, {wikiData}) {
 
             ...html.fragment(
               hasMidiProjectFiles && [
-                html.tag('p',
-                  {id: 'midi-project-files', class: ['content-heading']},
-                  language.$('releaseInfo.midiProjectFiles.heading')),
+                generateContentHeading({
+                  id: 'midi-project-files',
+                  title: language.$('releaseInfo.midiProjectFiles.heading'),
+                }),
 
                 generateAlbumAdditionalFilesList(album, track.midiProjectFiles),
               ]),
 
             ...html.fragment(
               hasAdditionalFiles && [
-                html.tag('p',
-                  {id: 'additional-files', class: ['content-heading']},
-                  language.$('releaseInfo.additionalFiles.heading', {
+                generateContentHeading({
+                  id: 'additional-files',
+                  title: language.$('releaseInfo.additionalFiles.heading', {
                     additionalFiles: language.countAdditionalFiles(numAdditionalFiles, {
                       unit: true,
                     }),
-                  })),
+                  })
+                }),
 
                 generateAlbumAdditionalFilesList(album, track.additionalFiles),
               ]),
 
             ...html.fragment(
               hasCommentary && [
-                html.tag('p', {class: ['content-heading']},
-                  language.$('releaseInfo.artistCommentary')),
+                generateContentHeading({
+                  id: 'artist-commentary',
+                  title: language.$('releaseInfo.artistCommentary'),
+                }),
 
                 html.tag('blockquote', generateCommentary({
                   link,
diff --git a/src/static/client.js b/src/static/client.js
index 87b74004..4eb1d2ba 100644
--- a/src/static/client.js
+++ b/src/static/client.js
@@ -452,6 +452,8 @@ function addHashLinkHandlers() {
   // This lets the scroll offset be consolidated where it makes sense, and
   // sets an appropriate offset when (re)loading a page with hash for free!
 
+  let wasHighlighted;
+
   for (const a of document.links) {
     const href = a.getAttribute('href');
     if (!href || !href.startsWith('#')) {
@@ -469,6 +471,17 @@ function addHashLinkHandlers() {
     const href = evt.target.getAttribute('href');
     const id = href.slice(1);
     const linked = document.getElementById(id);
+
+    if (!linked) {
+      return;
+    }
+
+    // Hide skipper box right away, so the layout is updated on time for the
+    // math operations coming up next.
+    const skipper = document.getElementById('skippers');
+    skipper.style.display = 'none';
+    setTimeout(() => skipper.style.display = '');
+
     const box = linked.getBoundingClientRect();
     const style = window.getComputedStyle(linked);
 
@@ -480,6 +493,27 @@ function addHashLinkHandlers() {
     evt.preventDefault();
     history.pushState({}, '', href);
     window.scrollTo({top: scrollY, behavior: 'smooth'});
+    linked.focus({preventScroll: true});
+
+    const maxScroll =
+        document.body.scrollHeight
+      - window.innerHeight;
+
+    if (scrollY > maxScroll && linked.classList.contains('content-heading')) {
+      if (wasHighlighted) {
+        wasHighlighted.classList.remove('highlight-hash-link');
+      }
+
+      wasHighlighted = linked;
+      linked.classList.add('highlight-hash-link');
+      linked.addEventListener('animationend', function handle(evt) {
+        if (evt.animationName === 'highlight-hash-link') {
+          linked.removeEventListener('animationend', handle);
+          linked.classList.remove('highlight-hash-link');
+          wasHighlighted = null;
+        }
+      });
+    }
   }
 }
 
diff --git a/src/static/site3.css b/src/static/site3.css
index 9128bd81..c522bc9d 100644
--- a/src/static/site3.css
+++ b/src/static/site3.css
@@ -208,7 +208,19 @@ body::before {
   box-shadow: 0 0 40px rgba(0, 0, 0, 0.5);
 }
 
-#skippers > .skipper:not(:last-child)::after {
+#skippers > * {
+  display: inline-block;
+}
+
+#skippers > .skipper-list:not(:last-child)::after {
+  display: inline-block;
+  content: "\00a0";
+  margin-left: 2px;
+  margin-right: -2px;
+  border-left: 1px dotted;
+}
+
+#skippers .skipper-list > .skipper:not(:last-child)::after {
   content: " \00b7 ";
   font-weight: 800;
 }
@@ -1137,6 +1149,37 @@ html[data-url-key="localized.home"] .carousel-container {
   margin-bottom: 0;
 }
 
+/* Custom hash links */
+
+.content-heading {
+  border-bottom: 3px double transparent;
+  margin-bottom: -3px;
+}
+
+.content-heading.highlight-hash-link {
+  animation: highlight-hash-link 4s;
+  animation-delay: 125ms;
+}
+
+/* This animation's name is referenced in JavaScript */
+@keyframes highlight-hash-link {
+  0% {
+    border-bottom-color: transparent;
+  }
+
+  10% {
+    border-bottom-color: white;
+  }
+
+  25% {
+    border-bottom-color: white;
+  }
+
+  100% {
+    border-bottom-color: transparent;
+  }
+}
+
 /* Sticky heading */
 
 #content [id] {
@@ -1145,7 +1188,7 @@ html[data-url-key="localized.home"] .carousel-container {
       74px /* Sticky heading */
     + 33px /* Sticky subheading */
     - 1em  /* One line of text (align bottom) */
-    - 4px  /* Padding for hanging letters */
+    - 12px /* Padding for hanging letters & focus ring */
   );
 }
 
diff --git a/src/strings-default.json b/src/strings-default.json
index 5d6935e1..97be1f02 100644
--- a/src/strings-default.json
+++ b/src/strings-default.json
@@ -181,11 +181,24 @@
   "misc.nav.gallery": "Gallery",
   "misc.pageTitle": "{TITLE}",
   "misc.pageTitle.withWikiName": "{TITLE} | {WIKI_NAME}",
-  "misc.skippers.skipToContent": "Skip to content",
-  "misc.skippers.skipToSidebar": "Skip to sidebar",
-  "misc.skippers.skipToSidebar.left": "Skip to sidebar (left)",
-  "misc.skippers.skipToSidebar.right": "Skip to sidebar (right)",
-  "misc.skippers.skipToFooter": "Skip to footer",
+  "misc.skippers.skipTo": "Skip to:",
+  "misc.skippers.content": "Content",
+  "misc.skippers.sidebar": "Sidebar",
+  "misc.skippers.sidebar.left": "Sidebar (left)",
+  "misc.skippers.sidebar.right": "Sidebar (right)",
+  "misc.skippers.header": "Header",
+  "misc.skippers.footer": "Footer",
+  "misc.skippers.contributors": "Contributors",
+  "misc.skippers.references": "References...",
+  "misc.skippers.referencedBy": "Referenced by...",
+  "misc.skippers.samples": "Samples...",
+  "misc.skippers.sampledBy": "Sampled by...",
+  "misc.skippers.featuredIn": "Featured in...",
+  "misc.skippers.lyrics": "Lyrics",
+  "misc.skippers.sheetMusicFiles": "Sheet music files",
+  "misc.skippers.midiProjectFiles": "MIDI/project files",
+  "misc.skippers.additionalFiles": "Additional files",
+  "misc.skippers.artistCommentary": "Commentary",
   "misc.socialEmbed.heading": "{WIKI_NAME} | {HEADING}",
   "misc.jumpTo": "Jump to:",
   "misc.jumpTo.withLinks": "Jump to: {LINKS}.",
diff --git a/src/write/bind-utilities.js b/src/write/bind-utilities.js
index 127afe2c..427111b4 100644
--- a/src/write/bind-utilities.js
+++ b/src/write/bind-utilities.js
@@ -19,6 +19,7 @@ import {
   generateAdditionalFilesList,
   generateAdditionalFilesShortcut,
   generateChronologyLinks,
+  generateContentHeading,
   generateCoverLink,
   generateInfoGalleryLinks,
   generateTrackListDividedByGroups,
@@ -192,6 +193,11 @@ export function bindUtilities({
     language,
   });
 
+  bound.generateContentHeading = bindOpts(generateContentHeading, {
+    [bindOpts.bindIndex]: 0,
+    html,
+  });
+
   bound.generateStickyHeadingContainer = bindOpts(generateStickyHeadingContainer, {
     [bindOpts.bindIndex]: 0,
     getRevealStringFromArtTags: bound.getRevealStringFromArtTags,
diff --git a/src/write/page-template.js b/src/write/page-template.js
index de369018..96036df2 100644
--- a/src/write/page-template.js
+++ b/src/write/page-template.js
@@ -401,6 +401,87 @@ export function generateDocumentHTML(pageInfo, {
     footerHTML,
   ].filter(Boolean).join('\n');
 
+  const processSkippers = skipperList =>
+    skipperList
+      .filter(Boolean)
+      .map(([href, stringSubkey]) =>
+        html.tag('span', {class: 'skipper'},
+          html.tag('a',
+            {href},
+            language.$(`misc.skippers.${stringSubkey}`))));
+
+  // Hilariously jank. Sorry!
+  const hasID = id => mainHTML.includes(`id="${id}"`);
+  const hasContributors = hasID('contributors');
+  const hasReferences = hasID('references');
+  const hasReferencedBy = hasID('referenced-by');
+  const hasSamples = hasID('samples');
+  const hasSampledBy = hasID('sampled-by');
+  const hasFeaturedIn = hasID('featured-in');
+  const hasLyrics = hasID('lyrics');
+  const hasSheetMusicFiles = hasID('sheet-music-files');
+  const hasMidiProjectFiles = hasID('midi-project-files');
+  const hasAdditionalFiles = hasID('additional-files');
+  const hasArtistCommentary = hasID('artist-commentary');
+
+  const skippersHTML =
+    mainHTML &&
+      html.tag('div', {id: 'skippers'}, [
+        html.tag('span', language.$('misc.skippers.skipTo')),
+        html.tag('div', {class: 'skipper-list'},
+          processSkippers([
+            ['#content', 'content'],
+            sidebarLeftHTML &&
+              [
+                '#sidebar-left',
+                sidebarRightHTML
+                  ? 'sidebar.left'
+                  : 'sidebar',
+              ],
+            sidebarRightHTML &&
+              [
+                '#sidebar-right',
+                sidebarLeftHTML
+                  ? 'sidebar.right'
+                  : 'sidebar',
+              ],
+            navHTML &&
+              ['#header', 'header'],
+            footerHTML &&
+              ['#footer', 'footer'],
+          ])),
+
+        html.tag('div',
+          {
+            [html.onlyIfContent]: true,
+            class: 'skipper-list'
+          },
+          processSkippers([
+            hasContributors &&
+              ['#contributors', 'contributors'],
+            hasReferences &&
+              ['#references', 'references'],
+            hasReferencedBy &&
+              ['#referenced-by', 'referencedBy'],
+            hasSamples &&
+              ['#samples', 'samples'],
+            hasSampledBy &&
+              ['#sampled-by', 'sampledBy'],
+            hasFeaturedIn &&
+              ['#featured-in', 'featuredIn'],
+            hasLyrics &&
+              ['#lyrics', 'lyrics'],
+            hasSheetMusicFiles &&
+              ['#sheet-music-files', 'sheetMusicFiles'],
+            hasMidiProjectFiles &&
+              ['#midi-project-files', 'midiProjectFiles'],
+            hasAdditionalFiles &&
+              ['#additional-files', 'additionalFiles'],
+            hasArtistCommentary &&
+              ['#artist-commentary', 'artistCommentary'],
+          ])),
+      ]);
+
   const infoCardHTML = html.tag('div', {id: 'info-card-container'},
     html.tag('div', {id: 'info-card-decor'},
       html.tag('div', {id: 'info-card'}, [
@@ -552,30 +633,7 @@ export function generateDocumentHTML(pageInfo, {
         [
           html.tag('div', {id: 'page-container'}, [
             mainHTML &&
-              html.tag('div', {id: 'skippers'},
-                [
-                  ['#content', language.$('misc.skippers.skipToContent')],
-                  sidebarLeftHTML &&
-                    [
-                      '#sidebar-left',
-                      sidebarRightHTML
-                        ? language.$('misc.skippers.skipToSidebar.left')
-                        : language.$('misc.skippers.skipToSidebar'),
-                    ],
-                  sidebarRightHTML &&
-                    [
-                      '#sidebar-right',
-                      sidebarLeftHTML
-                        ? language.$('misc.skippers.skipToSidebar.right')
-                        : language.$('misc.skippers.skipToSidebar'),
-                    ],
-                  footerHTML &&
-                    ['#footer', language.$('misc.skippers.skipToFooter')],
-                ]
-                  .filter(Boolean)
-                  .map(([href, title]) =>
-                    html.tag('span', {class: 'skipper'},
-                      html.tag('a', {href}, title)))),
+            skippersHTML,
             layoutHTML,
           ]),