eo-n/ui

Dark Mode

Create a theme provider.

components/theme-provider.tsx

import { createContext, useContext, useEffect, useState } from "react"
 
type Theme = "dark" | "light" | "system"
 
type ThemeProviderProps = {
  children: React.ReactNode
  defaultTheme?: Theme
  storageKey?: string
}
 
type ThemeProviderState = {
  theme: Theme
  setTheme: (theme: Theme) => void
}
 
const initialState: ThemeProviderState = {
  theme: "system",
  setTheme: () => null,
}
 
const ThemeProviderContext = createContext<ThemeProviderState>(initialState)
 
export function ThemeProvider({
  children,
  defaultTheme = "system",
  storageKey = "vite-ui-theme",
  ...props
}: ThemeProviderProps) {
  const [theme, setTheme] = useState<Theme>(
    () => (localStorage.getItem(storageKey) as Theme) || defaultTheme
  )
 
  useEffect(() => {
    const root = window.document.documentElement
 
    root.classList.remove("light", "dark")
 
    if (theme === "system") {
      const systemTheme = window.matchMedia("(prefers-color-scheme: dark)")
        .matches
        ? "dark"
        : "light"
 
      root.classList.add(systemTheme)
      return
    }
 
    root.classList.add(theme)
  }, [theme])
 
  const value = {
    theme,
    setTheme: (theme: Theme) => {
      localStorage.setItem(storageKey, theme)
      setTheme(theme)
    },
  }
 
  return (
    <ThemeProviderContext.Provider {...props} value={value}>
      {children}
    </ThemeProviderContext.Provider>
  )
}
 
export const useTheme = () => {
  const context = useContext(ThemeProviderContext)
 
  if (context === undefined)
    throw new Error("useTheme must be used within a ThemeProvider")
 
  return context
}

Wrap your root layout.

Add the ThemeProvider to your root layout.

App.tsx

import { ThemeProvider } from "@/components/theme-provider"
 
function App() {
  return (
    <ThemeProvider defaultTheme="dark" storageKey="vite-ui-theme">
      {children}
    </ThemeProvider>
  )
}
 
export default App

Add a mode toggle.

Place a mode toggle on your site to toggle between light and dark mode.

components/mode-toggle.tsx

import * as React from "react"
import { MoonIcon, SunIcon } from "lucide-react"
import { useTheme } from "next-themes"
 
import { Button } from "@/registry/default/ui/button"
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuPositioner,
  DropdownMenuTrigger,
} from "@/registry/default/ui/dropdown-menu"
 
export default function ModeToggle() {
  const { setTheme } = useTheme()
 
  return (
    <DropdownMenu>
      <DropdownMenuTrigger
        render={
          <Button variant="ghost" className="h-8 w-8 px-0">
            <SunIcon className="h-[1.2rem] w-[1.2rem] scale-100 rotate-0 transition-all dark:scale-0 dark:-rotate-90" />
            <MoonIcon className="absolute h-[1.2rem] w-[1.2rem] scale-0 rotate-90 transition-all dark:scale-100 dark:rotate-0" />
            <span className="sr-only">Toggle theme</span>
          </Button>
        }
      />
      <DropdownMenuPositioner align="end">
        <DropdownMenuContent>
          <DropdownMenuItem onClick={() => setTheme("light")}>
            Light
          </DropdownMenuItem>
          <DropdownMenuItem onClick={() => setTheme("dark")}>
            Dark
          </DropdownMenuItem>
          <DropdownMenuItem onClick={() => setTheme("system")}>
            System
          </DropdownMenuItem>
        </DropdownMenuContent>
      </DropdownMenuPositioner>
    </DropdownMenu>
  )
}

Vite

Dark Mode

Create a theme provider.

Wrap your root layout.

Add a mode toggle.

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