UI: Enable system option for theme toggle on NoteBook layout

.changeset/honest-dryers-cry.md

@@ -0,0 +1,5 @@
+---
+'fumadocs-ui': patch
+---
+
+Enable system option for theme toggle on NoteBook layout

packages/ui/src/components/layout/theme-toggle.tsx

@@ -1,47 +1,70 @@
 'use client';
 import { cva } from 'class-variance-authority';
-import { Moon, Sun } from 'lucide-react';
+import { Moon, Sun, Airplay } from 'lucide-react';
 import { useTheme } from 'next-themes';
-import { type ButtonHTMLAttributes } from 'react';
+import { type HTMLAttributes, useLayoutEffect, useState } from 'react';
 import { cn } from '@/utils/cn';
 
 const buttonVariants = cva(
   'size-7 rounded-full p-1.5 text-fd-muted-foreground',
   {
     variants: {
-      dark: {
-        true: 'dark:bg-fd-accent dark:text-fd-accent-foreground',
-        false:
-          'bg-fd-accent text-fd-accent-foreground dark:bg-transparent dark:text-fd-muted-foreground',
+      active: {
+        true: 'bg-fd-accent text-fd-accent-foreground',
+        false: 'text-fd-muted-foreground',
       },
     },
   },
 );
 
 export function ThemeToggle({
   className,
+  mode = 'light-dark',
   ...props
-}: ButtonHTMLAttributes<HTMLButtonElement>): React.ReactElement {
-  const { setTheme, resolvedTheme } = useTheme();
+}: HTMLAttributes<HTMLDivElement> & {
+  mode?: 'light-dark' | 'light-dark-system';
+}) {
+  const { setTheme, theme, resolvedTheme } = useTheme();
+  const [mounted, setMounted] = useState(false);
+  let value = mode === 'light-dark' ? resolvedTheme : theme;
+  if (!mounted) value = undefined;
 
-  const onToggle = () => {
-    setTheme(resolvedTheme === 'dark' ? 'light' : 'dark');
-  };
+  useLayoutEffect(() => {
+    setMounted(true);
+  }, []);
 
   return (
-    <button
-      type="button"
+    <div
       className={cn(
         'inline-flex items-center rounded-full border p-[3px]',
         className,
       )}
       data-theme-toggle=""
-      aria-label="Toggle Theme"
-      onClick={onToggle}
       {...props}
     >
-      <Sun className={cn(buttonVariants({ dark: false }))} />
-      <Moon className={cn(buttonVariants({ dark: true }))} />
-    </button>
+      <button
+        className={cn(buttonVariants({ active: value === 'light' }))}
+        onClick={() => setTheme('light')}
+        aria-label="Light Theme"
+      >
+        <Sun className="size-full" />
+      </button>
+      <button
+        className={cn(buttonVariants({ active: value === 'dark' }))}
+        onClick={() => setTheme('dark')}
+        aria-label="Dark Theme"
+      >
+        <Moon className="size-full" />
+      </button>
+      {mode === 'light-dark-system' ? (
+        <button
+          className={cn(buttonVariants({ active: value === 'system' }))}
+          onClick={() => setTheme('system')}
+          aria-label="System Theme"
+        >
+          <Airplay className="size-full" />
+        </button>
+      ) : null}
+    </div>
   );
 }

packages/ui/src/layouts/notebook.client.tsx

@@ -28,7 +28,7 @@ export function Navbar(props: HTMLAttributes<HTMLElement>) {
         } as object
       }
     >
-      <div className="mx-auto flex size-full flex-row items-center border-b border-fd-foreground/10 px-4 md:gap-1.5 lg:px-8">
+      <div className="mx-auto flex size-full flex-row items-center border-b border-fd-foreground/10 px-4 md:gap-1.5">
         {props.children}
       </div>
     </header>

packages/ui/src/layouts/notebook.tsx

@@ -75,7 +75,7 @@ export function DocsLayout({
   );
 
   const pageStyles: PageStyles = {
-    tocNav: cn('lg:px-4 xl:hidden'),
+    tocNav: cn('xl:hidden'),
     toc: cn('max-xl:hidden'),
     page: cn('mt-[var(--fd-nav-height)]'),
   };
@@ -203,7 +203,7 @@ function DocsNavbar({
           <Languages className="size-5" />
         </LanguageToggle>
       ) : null}
-      <ThemeToggle className="p-0 max-md:hidden" />
+      <ThemeToggle className="max-md:hidden" mode="light-dark-system" />
     </Navbar>
   );
 }