bootstrap_theme_toggler-2.0.0/js/colormodes.js

/*!
 * Color mode toggler for Bootstrap's docs (https://getbootstrap.com/)
 * Copyright 2011-2023 The Bootstrap Authors
 * Licensed under the Creative Commons Attribution 3.0 Unported License.
 */

(() => {
  // Using 'use strict' considered unecessary inside of Drupal modules
  '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' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
      document.documentElement.setAttribute('data-bs-theme', 'dark');
    } 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') ? document.querySelector('#bd-theme-text') : false;

    const activeThemeIcon = document.querySelector('.theme-icon-active use') ? document.querySelector('.theme-icon-active use') : false;

    const btnToActive = document.querySelector(`[data-bs-theme-value="${theme}"]`) ? document.querySelector(`[data-bs-theme-value="${theme}"]`) : false;

    const svgOfActiveBtn = (btnToActive && btnToActive.querySelector('svg use')) ? btnToActive.querySelector('svg use').getAttribute('href') : false;

    document.querySelectorAll('[data-bs-theme-value]').forEach(element => {
      element.classList.remove('active');
      element.setAttribute('aria-pressed', 'false');
    })

    if (btnToActive) {
        btnToActive.classList.add('active');
        btnToActive.setAttribute('aria-pressed', 'true');
      if (activeThemeIcon) {
        activeThemeIcon.setAttribute('href', svgOfActiveBtn);
      }
      if (themeSwitcherText) {
        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);
        })
      })
  })
})()