snapshot of https://github.com/shadcn-ui/ui.git (main, 2026-09-15; blobs > 131072B omitted)

apps/v4/components/active-theme.tsx

@@ -0,0 +1,56 @@
+"use client"
+
+import {
+  createContext,
+  useContext,
+  useEffect,
+  useState,
+  type ReactNode,
+} from "react"
+
+const DEFAULT_THEME = "default"
+
+type ThemeContextType = {
+  activeTheme: string
+  setActiveTheme: (theme: string) => void
+}
+
+const ThemeContext = createContext<ThemeContextType | undefined>(undefined)
+
+export function ActiveThemeProvider({
+  children,
+  initialTheme,
+}: {
+  children: ReactNode
+  initialTheme?: string
+}) {
+  const [activeTheme, setActiveTheme] = useState<string>(
+    () => initialTheme || DEFAULT_THEME
+  )
+
+  useEffect(() => {
+    Array.from(document.body.classList)
+      .filter((className) => className.startsWith("theme-"))
+      .forEach((className) => {
+        document.body.classList.remove(className)
+      })
+    document.body.classList.add(`theme-${activeTheme}`)
+    if (activeTheme.endsWith("-scaled")) {
+      document.body.classList.add("theme-scaled")
+    }
+  }, [activeTheme])
+
+  return (
+    <ThemeContext.Provider value={{ activeTheme, setActiveTheme }}>
+      {children}
+    </ThemeContext.Provider>
+  )
+}
+
+export function useThemeConfig() {
+  const context = useContext(ThemeContext)
+  if (context === undefined) {
+    throw new Error("useThemeConfig must be used within an ActiveThemeProvider")
+  }
+  return context
+}