Color-mode / dark-mode support

assets/js/color-mode.js

@@ -0,0 +1,80 @@
+/*!
+ * Color mode toggler for Bootstrap's docs (https://getbootstrap.com/)
+ * Copyright 2011-2024 The Bootstrap Authors
+ * Licensed under the Creative Commons Attribution 3.0 Unported License.
+ */
+
+(() => {
+  'use strict'
+
+  const getStoredTheme = () => localStorage.getItem('theme')
+  const setStoredTheme = theme => localStorage.setItem('theme', theme)
+
+  const getPreferredTheme = () => {
+    const storedTheme = getStoredTheme()
+    if (storedTheme) {
+      return storedTheme
+    }
+
+    return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'
+  }
+
+  const setTheme = theme => {
+    if (theme === 'auto') {
+      document.documentElement.setAttribute('data-bs-theme', (window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'))
+    } else {
+      document.documentElement.setAttribute('data-bs-theme', theme)
+    }
+  }
+
+  setTheme(getPreferredTheme())
+
+  const showActiveTheme = (theme, focus = false) => {
+    const themeSwitcher = document.querySelector('#bd-theme')
+
+    if (!themeSwitcher) {
+      return
+    }
+
+    const themeSwitcherText = document.querySelector('#bd-theme-text')
+    const activeThemeIcon = document.querySelector('.theme-icon-active use')
+    const btnToActive = document.querySelector(`[data-bs-theme-value="${theme}"]`)
+    const svgOfActiveBtn = btnToActive.querySelector('svg use').getAttribute('href')
+
+    document.querySelectorAll('[data-bs-theme-value]').forEach(element => {
+      element.classList.remove('active')
+      element.setAttribute('aria-pressed', 'false')
+    })
+
+    btnToActive.classList.add('active')
+    btnToActive.setAttribute('aria-pressed', 'true')
+    activeThemeIcon.setAttribute('href', svgOfActiveBtn)
+    const themeSwitcherLabel = `${themeSwitcherText.textContent} (${btnToActive.dataset.bsThemeValue})`
+    themeSwitcher.setAttribute('aria-label', themeSwitcherLabel)
+
+    if (focus) {
+      themeSwitcher.focus()
+    }
+  }
+
+  window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', () => {
+    const storedTheme = getStoredTheme()
+    if (storedTheme !== 'light' && storedTheme !== 'dark') {
+      setTheme(getPreferredTheme())
+    }
+  })
+
+  window.addEventListener('DOMContentLoaded', () => {
+    showActiveTheme(getPreferredTheme())
+
+    document.querySelectorAll('[data-bs-theme-value]')
+      .forEach(toggle => {
+        toggle.addEventListener('click', () => {
+          const theme = toggle.getAttribute('data-bs-theme-value')
+          setStoredTheme(theme)
+          setTheme(theme)
+          showActiveTheme(theme, true)
+        })
+      })
+  })
+})()

assets/scss/_nav.scss

@@ -57,7 +57,7 @@
   // For .td-search__input styling, see _search.scss
 
   .dropdown {
-    min-width: 100px;
+    min-width: 50px;
   }
 
   @include media-breakpoint-up(md) {

layouts/partials/navbar.html

@@ -4,6 +4,18 @@
 -}}
 {{ $baseURL := urls.Parse $.Site.Params.Baseurl -}}
 
+<style>
+  .bi {
+    width: 1em;
+    height: 1em;
+    vertical-align: -.125em;
+    fill: currentcolor;
+  }
+  .td-navbar .dropdown-menu .active .bi {
+    display: block !important
+  }
+</style>
+
 <nav class="td-navbar js-navbar-scroll
             {{- if $cover }} td-navbar-cover {{- end }}" data-bs-theme="dark">
 <div class="container-fluid flex-column flex-md-row">
@@ -57,6 +69,11 @@
         {{ partial "navbar-lang-selector.html" . -}}
       </li>
       {{ end -}}
+      {{ if .Site.Params.ui.colorModeEnabled -}}
+      <li class="nav-item dropdown">
+        {{ partial "theme-toggler" . }}
+      </li>
+      {{ end -}}
     </ul>
   </div>
   <div class="d-none d-lg-block">

layouts/partials/scripts.html

@@ -73,6 +73,10 @@
 {{- partial "scripts/mermaid.html" . -}}
 {{ end -}}
 
+{{ if .Site.Params.ui.colorModeEnabled -}}
+  {{ $jsArray = $jsArray | append (resources.Get "js/color-mode.js") -}}
+{{ end -}}
+
 {{ $js := $jsArray | resources.Concat "js/main.js" -}}
 {{ if hugo.IsProduction -}}
   {{ $js := $js | minify | fingerprint -}}

layouts/partials/theme-toggler.html

@@ -0,0 +1,54 @@
+{{/* Adapted from: https://github.com/twbs/bootstrap/blob/main/site/layouts/partials/icons.html */ -}}
+
+<svg xmlns="http://www.w3.org/2000/svg" class="d-none">
+  <symbol id="check2" viewBox="0 0 16 16">
+    <path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z"/>
+  </symbol>
+  <symbol id="circle-half" viewBox="0 0 16 16">
+    <path d="M8 15A7 7 0 1 0 8 1v14zm0 1A8 8 0 1 1 8 0a8 8 0 0 1 0 16z"/>
+  </symbol>
+  <symbol id="moon-stars-fill" viewBox="0 0 16 16">
+    <path d="M6 .278a.768.768 0 0 1 .08.858 7.208 7.208 0 0 0-.878 3.46c0 4.021 3.278 7.277 7.318 7.277.527 0 1.04-.055 1.533-.16a.787.787 0 0 1 .81.316.733.733 0 0 1-.031.893A8.349 8.349 0 0 1 8.344 16C3.734 16 0 12.286 0 7.71 0 4.266 2.114 1.312 5.124.06A.752.752 0 0 1 6 .278z"/>
+    <path d="M10.794 3.148a.217.217 0 0 1 .412 0l.387 1.162c.173.518.579.924 1.097 1.097l1.162.387a.217.217 0 0 1 0 .412l-1.162.387a1.734 1.734 0 0 0-1.097 1.097l-.387 1.162a.217.217 0 0 1-.412 0l-.387-1.162A1.734 1.734 0 0 0 9.31 6.593l-1.162-.387a.217.217 0 0 1 0-.412l1.162-.387a1.734 1.734 0 0 0 1.097-1.097l.387-1.162zM13.863.099a.145.145 0 0 1 .274 0l.258.774c.115.346.386.617.732.732l.774.258a.145.145 0 0 1 0 .274l-.774.258a1.156 1.156 0 0 0-.732.732l-.258.774a.145.145 0 0 1-.274 0l-.258-.774a1.156 1.156 0 0 0-.732-.732l-.774-.258a.145.145 0 0 1 0-.274l.774-.258c.346-.115.617-.386.732-.732L13.863.1z"/>
+  </symbol>
+  <symbol id="sun-fill" viewBox="0 0 16 16">
+    <path d="M8 12a4 4 0 1 0 0-8 4 4 0 0 0 0 8zM8 0a.5.5 0 0 1 .5.5v2a.5.5 0 0 1-1 0v-2A.5.5 0 0 1 8 0zm0 13a.5.5 0 0 1 .5.5v2a.5.5 0 0 1-1 0v-2A.5.5 0 0 1 8 13zm8-5a.5.5 0 0 1-.5.5h-2a.5.5 0 0 1 0-1h2a.5.5 0 0 1 .5.5zM3 8a.5.5 0 0 1-.5.5h-2a.5.5 0 0 1 0-1h2A.5.5 0 0 1 3 8zm10.657-5.657a.5.5 0 0 1 0 .707l-1.414 1.415a.5.5 0 1 1-.707-.708l1.414-1.414a.5.5 0 0 1 .707 0zm-9.193 9.193a.5.5 0 0 1 0 .707L3.05 13.657a.5.5 0 0 1-.707-.707l1.414-1.414a.5.5 0 0 1 .707 0zm9.193 2.121a.5.5 0 0 1-.707 0l-1.414-1.414a.5.5 0 0 1 .707-.707l1.414 1.414a.5.5 0 0 1 0 .707zM4.464 4.465a.5.5 0 0 1-.707 0L2.343 3.05a.5.5 0 1 1 .707-.707l1.414 1.414a.5.5 0 0 1 0 .708z"/>
+  </symbol>
+</svg>
+
+{{/* Adapted from: https://github.com/twbs/bootstrap/blob/main/site/layouts/partials/theme-toggler.html */ -}}
+
+{{ $isExamples := eq .Layout "examples" -}}
+<button class="btn {{ if $isExamples }}btn-bd-primary{{ else }}btn-link nav-link px-0 px-lg-2{{ end }} py-2 dropdown-toggle d-flex align-items-center"
+        id="bd-theme"
+        type="button"
+        aria-expanded="false"
+        data-bs-toggle="dropdown"
+        {{ if not $isExamples }}data-bs-display="static"{{ end }}
+        aria-label="Toggle theme (auto)">
+  <svg class="bi my-1 theme-icon-active"><use href="#circle-half"></use></svg>
+  <span class="{{ if $isExamples }}visually-hidden{{ else }}d-lg-none ms-2{{ end }}" id="bd-theme-text">Toggle theme</span>
+</button>
+<ul class="dropdown-menu dropdown-menu-end{{ if $isExamples }} shadow{{ end }}" aria-labelledby="bd-theme-text">
+  <li>
+    <button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="light" aria-pressed="false">
+      <svg class="bi me-2 opacity-50"><use href="#sun-fill"></use></svg>
+      Light
+      <svg class="bi ms-auto d-none"><use href="#check2"></use></svg>
+    </button>
+  </li>
+  <li>
+    <button type="button" class="dropdown-item d-flex align-items-center" data-bs-theme-value="dark" aria-pressed="false">
+      <svg class="bi me-2 opacity-50"><use href="#moon-stars-fill"></use></svg>
+      Dark
+      <svg class="bi ms-auto d-none"><use href="#check2"></use></svg>
+    </button>
+  </li>
+  <li>
+    <button type="button" class="dropdown-item d-flex align-items-center active" data-bs-theme-value="auto" aria-pressed="true">
+      <svg class="bi me-2 opacity-50"><use href="#circle-half"></use></svg>
+      Auto
+      <svg class="bi ms-auto d-none"><use href="#check2"></use></svg>
+    </button>
+  </li>
+</ul>

userguide/hugo.yaml

@@ -71,6 +71,7 @@ params:
   search:
     # algolia:
   ui:
+    colorModeEnabled: true
     sidebar_cache_limit: 10
     sidebar_menu_compact: true
     sidebar_menu_foldable: false