Merge commit '8be91ee3d9' as 'themes/tabi-lean'

themes/tabi-lean/static/js/themeSwitcher.js

@@ -0,0 +1,74 @@
+// Get the theme switcher button elements.
+const themeSwitcher = document.querySelector('.theme-switcher');
+const themeResetter = document.querySelector('.theme-resetter');
+const defaultTheme = document.documentElement.getAttribute('data-default-theme');
+
+function getSystemThemePreference() {
+    return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+}
+
+// Determine the initial theme.
+let currentTheme =
+    localStorage.getItem('theme') ||
+    document.documentElement.getAttribute('data-theme') ||
+    getSystemThemePreference();
+
+function setTheme(theme, saveToLocalStorage = false) {
+    document.documentElement.setAttribute('data-theme', theme);
+    currentTheme = theme;
+    themeSwitcher.setAttribute('aria-pressed', theme === 'dark');
+
+    if (saveToLocalStorage) {
+        localStorage.setItem('theme', theme);
+        themeResetter.classList.add('has-custom-theme');
+    } else {
+        localStorage.removeItem('theme');
+        themeResetter.classList.remove('has-custom-theme');
+    }
+
+    // Dispatch a custom event for comment systems.
+    window.dispatchEvent(new CustomEvent('themeChanged', { detail: { theme } }));
+}
+
+function resetTheme() {
+    setTheme(defaultTheme || getSystemThemePreference());
+}
+
+// Function to switch between dark and light themes.
+function switchTheme() {
+    setTheme(currentTheme === 'dark' ? 'light' : 'dark', true);
+}
+
+// Initialize the theme switcher button.
+themeSwitcher.addEventListener('click', switchTheme);
+themeResetter.addEventListener('click', resetTheme);
+
+// Update the theme based on system preference if necessary.
+if (!defaultTheme) {
+    window
+        .matchMedia('(prefers-color-scheme: dark)')
+        .addEventListener('change', (e) => {
+            setTheme(e.matches ? 'dark' : 'light');
+        });
+}
+
+// Set initial ARIA attribute and custom theme class.
+themeSwitcher.setAttribute('aria-pressed', currentTheme === 'dark');
+if (localStorage.getItem('theme')) {
+    themeResetter.classList.add('has-custom-theme');
+}
+
+// Function to handle keydown event on theme toggler buttons.
+function handleThemeTogglerKeydown(event) {
+    if (event.key === 'Enter' || event.key === ' ') {
+        event.preventDefault();
+        if (event.target === themeSwitcher) {
+            switchTheme();
+        } else if (event.target === themeResetter) {
+            resetTheme();
+        }
+    }
+}
+
+themeSwitcher.addEventListener('keydown', handleThemeTogglerKeydown);
+themeResetter.addEventListener('keydown', handleThemeTogglerKeydown);