{
  "$schema": "https://ui.shadcn.com/schema/registry-item.json",
  "name": "lcd-display",
  "title": "LCD Display",
  "description": "A dot-matrix screen in a bezel, backlit in the light theme and glowing in the dark one: rows of dim labels and bright values in the theme colour or amber, green, cyan or red, dotted separators, a blinking status pixel and dropdown values built on Base UI's Select.",
  "dependencies": [
    "@base-ui/react",
    "class-variance-authority"
  ],
  "files": [
    {
      "path": "components/ui/lcd-display.tsx",
      "content": "\"use client\";\n\nimport { Select as SelectPrimitive } from \"@base-ui/react/select\";\nimport { cva } from \"class-variance-authority\";\nimport {\n  createContext,\n  useCallback,\n  useContext,\n  useEffect,\n  useId,\n  useLayoutEffect,\n  useMemo,\n  useRef,\n  useState,\n} from \"react\";\nimport type { ComponentProps, ReactNode, Ref, RefObject } from \"react\";\n\nimport { cn } from \"@/lib/utils\";\n\ntype LcdDisplayVariant = \"primary\" | \"amber\" | \"green\" | \"cyan\" | \"red\";\ntype LcdDisplaySize = \"sm\" | \"default\" | \"lg\";\ntype LcdDisplayAppearance = \"auto\" | \"light\" | \"dark\";\n\n/**\n * A backlit screen: pale glass tinted by the ink, with dark pixels and no\n * glow, like a calculator or a pager.\n */\nconst LIGHT_SCREEN =\n  \"[--lcd-display-bezel-edge:oklch(0.85_0.004_250)] [--lcd-display-bezel-ring:rgb(0_0_0/0.14)] [--lcd-display-bezel-shadow:inset_0_1px_0_rgb(255_255_255/0.8),0_1px_3px_rgb(0_0_0/0.18)] [--lcd-display-bezel:oklch(0.95_0.003_250)] [--lcd-display-glass:oklch(from_var(--lcd-display-ink)_0.93_calc(c*0.35)_h)] [--lcd-display-glow:color-mix(in_oklab,var(--lcd-display-lit)_22%,transparent)] [--lcd-display-lit:color-mix(in_oklab,var(--lcd-display-ink),black_62%)] [--lcd-display-recess:inset_0_1px_4px_rgb(0_0_0/0.28),inset_0_0_0_1px_rgb(0_0_0/0.2)] [--lcd-display-scanline:rgb(0_0_0/0.04)] [--lcd-display-sheen:rgb(255_255_255/0.35)]\";\n\n/** An unlit dark glass where the ink itself glows. */\nconst DARK_SCREEN =\n  \"[--lcd-display-bezel-edge:oklch(0.24_0.004_250)] [--lcd-display-bezel-ring:rgb(0_0_0/0.7)] [--lcd-display-bezel-shadow:inset_0_1px_0_rgb(255_255_255/0.06),0_2px_6px_rgb(0_0_0/0.5)] [--lcd-display-bezel:oklch(0.33_0.004_250)] [--lcd-display-glass:oklch(0.15_0.004_200)] [--lcd-display-glow:color-mix(in_oklab,var(--lcd-display-lit)_60%,transparent)] [--lcd-display-lit:var(--lcd-display-ink)] [--lcd-display-recess:inset_0_2px_10px_rgb(0_0_0/0.9),inset_0_0_0_1px_rgb(0_0_0/0.8)] [--lcd-display-scanline:rgb(0_0_0/0.22)] [--lcd-display-sheen:rgb(255_255_255/0.05)]\";\n\n/** The dark screen under the site's `.dark` class, written out for Tailwind. */\nconst DARK_SCREEN_IN_DARK_THEME =\n  \"dark:[--lcd-display-bezel-edge:oklch(0.24_0.004_250)] dark:[--lcd-display-bezel-ring:rgb(0_0_0/0.7)] dark:[--lcd-display-bezel-shadow:inset_0_1px_0_rgb(255_255_255/0.06),0_2px_6px_rgb(0_0_0/0.5)] dark:[--lcd-display-bezel:oklch(0.33_0.004_250)] dark:[--lcd-display-glass:oklch(0.15_0.004_200)] dark:[--lcd-display-glow:color-mix(in_oklab,var(--lcd-display-lit)_60%,transparent)] dark:[--lcd-display-lit:var(--lcd-display-ink)] dark:[--lcd-display-recess:inset_0_2px_10px_rgb(0_0_0/0.9),inset_0_0_0_1px_rgb(0_0_0/0.8)] dark:[--lcd-display-scanline:rgb(0_0_0/0.22)] dark:[--lcd-display-sheen:rgb(255_255_255/0.05)]\";\n\n/**\n * The hardware colours, the ink and the dot grid. The lit, dim and unlit\n * pixels are mixed from `--lcd-display-ink`, so a custom colour needs only\n * that one variable, in both appearances.\n */\nconst lcdDisplayVariants = cva(\n  \"[--lcd-display-font:var(--font-mono)] [--lcd-display-ink-dim:color-mix(in_oklab,var(--lcd-display-lit)_40%,transparent)] [--lcd-display-ink-unlit:color-mix(in_oklab,var(--lcd-display-lit)_7%,transparent)] [--lcd-display-pitch:2px]\",\n  {\n    defaultVariants: {\n      appearance: \"auto\",\n      size: \"default\",\n      variant: \"primary\",\n    },\n    variants: {\n      appearance: {\n        auto: `${LIGHT_SCREEN} ${DARK_SCREEN_IN_DARK_THEME}`,\n        dark: DARK_SCREEN,\n        light: LIGHT_SCREEN,\n      },\n      size: {\n        default: \"text-lg\",\n        lg: \"text-2xl\",\n        sm: \"text-sm\",\n      },\n      variant: {\n        amber: \"[--lcd-display-ink:oklch(0.76_0.13_52)]\",\n        cyan: \"[--lcd-display-ink:oklch(0.84_0.12_205)]\",\n        green: \"[--lcd-display-ink:oklch(0.85_0.19_142)]\",\n        primary: \"[--lcd-display-ink:var(--primary)]\",\n        red: \"[--lcd-display-ink:oklch(0.68_0.2_27)]\",\n      },\n    },\n  }\n);\n\ninterface LcdDisplayContextValue {\n  /** The display itself, whose variables the portalled popup copies. */\n  rootRef: RefObject<HTMLDivElement | null> | null;\n  appearance: LcdDisplayAppearance;\n  variant: LcdDisplayVariant;\n  size: LcdDisplaySize;\n  matrix: boolean;\n  scanlines: boolean;\n}\n\nconst LcdDisplayContext = createContext<LcdDisplayContextValue>({\n  appearance: \"auto\",\n  matrix: true,\n  rootRef: null,\n  scanlines: true,\n  size: \"default\",\n  variant: \"primary\",\n});\n\nconst RowContext = createContext<{\n  labelId: string;\n  setCustomLabelId: (id: string | undefined) => void;\n} | null>(null);\n\n/**\n * The variables a caller may set on the display. The popup is portalled out\n * of it, so it copies them instead of inheriting them.\n */\nconst SHARED_VARIABLES = [\n  \"--lcd-display-bezel\",\n  \"--lcd-display-bezel-edge\",\n  \"--lcd-display-font\",\n  \"--lcd-display-glass\",\n  \"--lcd-display-glow\",\n  \"--lcd-display-ink\",\n  \"--lcd-display-ink-dim\",\n  \"--lcd-display-ink-unlit\",\n  \"--lcd-display-lit\",\n  \"--lcd-display-pitch\",\n] as const;\n\n/** Points every ref at the element, so a caller's ref works beside ours. */\nconst mergeRefs =\n  <T,>(...refs: (Ref<T> | undefined)[]) =>\n  (node: T) => {\n    const cleanups = refs.map((ref) => {\n      if (typeof ref === \"function\") {\n        const cleanup = ref(node);\n        return typeof cleanup === \"function\" ? cleanup : () => ref(null);\n      }\n      if (ref) {\n        ref.current = node;\n        return () => {\n          ref.current = null;\n        };\n      }\n      return null;\n    });\n    return () => {\n      for (const cleanup of cleanups) {\n        cleanup?.();\n      }\n    };\n  };\n\n/**\n * Dims a part for a moment when its text changes, like segments redrawing.\n * Watches the DOM rather than renders, so it also catches text that a child\n * updates on its own, like a select's value, and costs no render.\n */\nconst useChangeFlicker = (ref: RefObject<HTMLElement | null>) => {\n  useEffect(() => {\n    const element = ref.current;\n    if (!element) {\n      return;\n    }\n    let text = element.textContent;\n    let frame = 0;\n    const observer = new MutationObserver(() => {\n      if (element.textContent === text) {\n        return;\n      }\n      text = element.textContent;\n      cancelAnimationFrame(frame);\n      element.dataset.changed = \"\";\n      // Two frames: one to paint dimmed, one to start the fade back.\n      frame = requestAnimationFrame(() => {\n        frame = requestAnimationFrame(() => {\n          delete element.dataset.changed;\n        });\n      });\n    });\n    observer.observe(element, {\n      characterData: true,\n      childList: true,\n      subtree: true,\n    });\n    return () => {\n      observer.disconnect();\n      cancelAnimationFrame(frame);\n      delete element.dataset.changed;\n    };\n  }, [ref]);\n};\n\nconst FLICKER =\n  \"transition-opacity duration-150 data-changed:opacity-35 data-changed:duration-0 motion-reduce:transition-none motion-reduce:data-changed:opacity-100\";\n\n/** The glass: unlit dots behind, scanlines in front, glowing dotted ink between. */\nconst LcdScreen = ({\n  matrix,\n  scanlines,\n  className,\n  contentClassName,\n  children,\n}: {\n  matrix: boolean;\n  scanlines: boolean;\n  className?: string;\n  contentClassName?: string;\n  children: ReactNode;\n}) => (\n  <div\n    className={cn(\n      \"relative isolate overflow-hidden rounded-md bg-(--lcd-display-glass) shadow-(--lcd-display-recess)\",\n      matrix &&\n        \"before:pointer-events-none before:absolute before:inset-0 before:bg-[radial-gradient(circle,var(--lcd-display-ink-unlit)_45%,transparent_55%)] before:bg-size-[var(--lcd-display-pitch)_var(--lcd-display-pitch)]\",\n      \"after:pointer-events-none after:absolute after:inset-0 after:bg-[linear-gradient(to_bottom,var(--lcd-display-sheen),transparent_45%)]\",\n      scanlines &&\n        \"after:bg-[linear-gradient(to_bottom,var(--lcd-display-sheen),transparent_45%),repeating-linear-gradient(to_bottom,transparent_0_2px,var(--lcd-display-scanline)_2px_3px)]\",\n      className\n    )}\n    data-slot=\"lcd-display-screen\"\n  >\n    <div className=\"drop-shadow-[0_0_3px_var(--lcd-display-glow)]\">\n      <div\n        className={cn(\n          \"relative\",\n          matrix &&\n            \"mask-[radial-gradient(circle,#000_58%,transparent_64%)] mask-size-[var(--lcd-display-pitch)_var(--lcd-display-pitch)]\",\n          contentClassName\n        )}\n        data-slot=\"lcd-display-content\"\n      >\n        {children}\n      </div>\n    </div>\n  </div>\n);\n\nexport interface LcdDisplayProps extends ComponentProps<\"div\"> {\n  /**\n   * The ink colour. `primary` follows the theme's `--primary`; the others are\n   * fixed hardware inks. Default `primary`.\n   */\n  variant?: LcdDisplayVariant;\n  /**\n   * `light` is a backlit screen with dark pixels, `dark` an unlit screen with\n   * glowing ink, and `auto` follows the theme. Default `auto`.\n   */\n  appearance?: LcdDisplayAppearance;\n  /** The text size; rows, separator and status follow it. Default `default`. */\n  size?: LcdDisplaySize;\n  /** Break the text into dots on a `--lcd-display-pitch` grid. Default true. */\n  matrix?: boolean;\n  /** Faint horizontal scanlines over the glass. Default true. */\n  scanlines?: boolean;\n}\n\n/**\n * An LCD screen in a bezel: backlit with dark pixels in the light theme, and\n * glowing ink on dark glass in the dark one. Its ink is `--lcd-display-ink`.\n */\nexport const LcdDisplay = ({\n  variant = \"primary\",\n  appearance = \"auto\",\n  size = \"default\",\n  matrix = true,\n  scanlines = true,\n  className,\n  children,\n  ref,\n  ...props\n}: LcdDisplayProps) => {\n  const rootRef = useRef<HTMLDivElement>(null);\n  const mergedRef = useMemo(() => mergeRefs(rootRef, ref), [ref]);\n  const context = useMemo(\n    () => ({ appearance, matrix, rootRef, scanlines, size, variant }),\n    [appearance, matrix, scanlines, size, variant]\n  );\n  return (\n    <LcdDisplayContext.Provider value={context}>\n      <div\n        className={cn(\n          lcdDisplayVariants({ appearance, size, variant }),\n          \"rounded-lg bg-linear-to-b from-(--lcd-display-bezel) to-(--lcd-display-bezel-edge) p-1.5 font-(family-name:--lcd-display-font) leading-none tracking-[0.12em] uppercase shadow-(--lcd-display-bezel-shadow) ring-1 ring-(--lcd-display-bezel-ring)\",\n          className\n        )}\n        data-appearance={appearance}\n        data-matrix={matrix ? \"\" : undefined}\n        data-slot=\"lcd-display\"\n        data-size={size}\n        data-variant={variant}\n        ref={mergedRef}\n        role=\"group\"\n        {...props}\n      >\n        <LcdScreen\n          contentClassName=\"flex flex-col px-4 py-2\"\n          matrix={matrix}\n          scanlines={scanlines}\n        >\n          {children}\n        </LcdScreen>\n      </div>\n    </LcdDisplayContext.Provider>\n  );\n};\n\n/** One line of the screen: a label on the left, a value on the right. */\nexport const LcdDisplayRow = ({\n  className,\n  children,\n  ...props\n}: ComponentProps<\"div\">) => {\n  const generatedId = useId();\n  const [customLabelId, setCustomLabelId] = useState<string>();\n  const labelId = customLabelId ?? generatedId;\n  const row = useMemo(() => ({ labelId, setCustomLabelId }), [labelId]);\n  return (\n    <RowContext.Provider value={row}>\n      <div\n        className={cn(\n          \"flex items-center justify-between gap-8 py-3\",\n          className\n        )}\n        data-slot=\"lcd-display-row\"\n        {...props}\n      >\n        {children}\n      </div>\n    </RowContext.Provider>\n  );\n};\n\n/** Dim text that names a row, and the select in it. */\nexport const LcdDisplayLabel = ({\n  className,\n  id,\n  ...props\n}: ComponentProps<\"span\">) => {\n  const row = useContext(RowContext);\n  const setCustomLabelId = row?.setCustomLabelId;\n  // A caller's id replaces the generated one, so the row's select points at it.\n  useLayoutEffect(() => {\n    if (!setCustomLabelId || id === undefined) {\n      return;\n    }\n    setCustomLabelId(id);\n    return () => setCustomLabelId(undefined);\n  }, [id, setCustomLabelId]);\n  return (\n    <span\n      className={cn(\"text-(--lcd-display-ink-dim)\", className)}\n      data-slot=\"lcd-display-label\"\n      id={id ?? row?.labelId}\n      {...props}\n    />\n  );\n};\n\nexport interface LcdDisplayValueProps extends ComponentProps<\"span\"> {\n  /** Announce changes to screen readers (`aria-live=\"polite\"`). Default false. */\n  live?: boolean;\n}\n\n/** Bright, glowing text that flickers when it changes. */\nexport const LcdDisplayValue = ({\n  live = false,\n  className,\n  ref,\n  ...props\n}: LcdDisplayValueProps) => {\n  const ownRef = useRef<HTMLSpanElement>(null);\n  const mergedRef = useMemo(() => mergeRefs(ownRef, ref), [ref]);\n  useChangeFlicker(ownRef);\n  return (\n    <span\n      aria-live={live ? \"polite\" : undefined}\n      className={cn(\n        \"text-(--lcd-display-lit) tabular-nums\",\n        FLICKER,\n        className\n      )}\n      data-slot=\"lcd-display-value\"\n      ref={mergedRef}\n      {...props}\n    />\n  );\n};\n\n/** A dotted rule between rows. */\nexport const LcdDisplaySeparator = ({\n  className,\n  ...props\n}: ComponentProps<\"div\">) => (\n  <div\n    className={cn(\n      \"h-(--lcd-display-pitch) shrink-0 bg-[radial-gradient(circle,var(--lcd-display-ink-dim)_45%,transparent_55%)] bg-size-[calc(var(--lcd-display-pitch)*2)_var(--lcd-display-pitch)]\",\n      className\n    )}\n    data-slot=\"lcd-display-separator\"\n    role=\"separator\"\n    {...props}\n  />\n);\n\nexport interface LcdDisplayStatusProps extends ComponentProps<\"span\"> {\n  /** `idle` blinks slowly, `busy` quickly, `off` shows nothing lit. Default `idle`. */\n  state?: \"idle\" | \"busy\" | \"off\";\n}\n\n/** The blinking pixel in the bottom-right corner of the screen. */\nexport const LcdDisplayStatus = ({\n  state = \"idle\",\n  className,\n  ...props\n}: LcdDisplayStatusProps) => (\n  <span\n    aria-hidden\n    className={cn(\n      \"absolute right-2 bottom-2 size-1.5 animate-pulse bg-(--lcd-display-lit) data-[state=busy]:[animation-duration:0.6s] data-[state=off]:animate-none data-[state=off]:bg-(--lcd-display-ink-unlit) motion-reduce:animate-none\",\n      className\n    )}\n    data-slot=\"lcd-display-status\"\n    data-state={state}\n    {...props}\n  />\n);\n\n/** A row value the user can change, built on Base UI's Select. */\nexport const LcdDisplaySelect = <Value,>(\n  props: SelectPrimitive.Root.Props<Value>\n) => <SelectPrimitive.Root {...props} />;\n\n/** A 5 × 3 pixel chevron. */\nconst PixelChevron = () => (\n  <svg\n    aria-hidden\n    className=\"h-1.5 w-2.5 shrink-0\"\n    fill=\"currentColor\"\n    shapeRendering=\"crispEdges\"\n    viewBox=\"0 0 5 3\"\n  >\n    <path d=\"M0 0h1v1H0zM4 0h1v1H4zM1 1h1v1H1zM3 1h1v1H3zM2 2h1v1H2z\" />\n  </svg>\n);\n\nexport interface LcdDisplaySelectTriggerProps\n  extends SelectPrimitive.Trigger.Props {\n  /** Shown while nothing is selected. */\n  placeholder?: ReactNode;\n}\n\n/** The selected value and a pixel chevron. Named by the row's label. */\nexport const LcdDisplaySelectTrigger = ({\n  placeholder,\n  className,\n  children,\n  ref,\n  ...props\n}: LcdDisplaySelectTriggerProps) => {\n  const row = useContext(RowContext);\n  const ownRef = useRef<HTMLButtonElement>(null);\n  const mergedRef = useMemo(() => mergeRefs(ownRef, ref), [ref]);\n  useChangeFlicker(ownRef);\n  return (\n    <SelectPrimitive.Trigger\n      aria-labelledby={row?.labelId}\n      className={cn(\n        \"-mx-1 inline-flex cursor-pointer items-center gap-3 rounded-sm px-1 py-0.5 text-(--lcd-display-lit) uppercase tabular-nums outline-none focus-visible:ring-1 focus-visible:ring-(--lcd-display-lit) disabled:cursor-default disabled:text-(--lcd-display-ink-dim) data-placeholder:text-(--lcd-display-ink-dim)\",\n        FLICKER,\n        className\n      )}\n      data-slot=\"lcd-display-select-trigger\"\n      ref={mergedRef}\n      {...props}\n    >\n      {children ?? <SelectPrimitive.Value placeholder={placeholder} />}\n      <SelectPrimitive.Icon className=\"transition-transform duration-150 data-popup-open:rotate-180 motion-reduce:transition-none\">\n        <PixelChevron />\n      </SelectPrimitive.Icon>\n    </SelectPrimitive.Trigger>\n  );\n};\n\nexport interface LcdDisplaySelectContentProps\n  extends\n    SelectPrimitive.Popup.Props,\n    Pick<\n      SelectPrimitive.Positioner.Props,\n      \"align\" | \"alignOffset\" | \"side\" | \"sideOffset\"\n    > {}\n\n/** The list of choices, drawn as a small screen in the display's ink. */\nexport const LcdDisplaySelectContent = ({\n  align = \"end\",\n  alignOffset = 0,\n  side = \"bottom\",\n  sideOffset = 8,\n  className,\n  children,\n  ref,\n  ...props\n}: LcdDisplaySelectContentProps) => {\n  const { appearance, matrix, rootRef, scanlines, size, variant } =\n    useContext(LcdDisplayContext);\n  // Copies the display's variables, so a custom ink or font reaches the popup.\n  const shareVariables = useCallback(\n    (popup: HTMLDivElement | null) => {\n      const root = rootRef?.current;\n      if (!(popup && root)) {\n        return;\n      }\n      const style = getComputedStyle(root);\n      for (const name of SHARED_VARIABLES) {\n        const value = style.getPropertyValue(name);\n        if (value) {\n          popup.style.setProperty(name, value);\n        }\n      }\n    },\n    [rootRef]\n  );\n  const mergedRef = useMemo(\n    () => mergeRefs(shareVariables, ref),\n    [shareVariables, ref]\n  );\n  return (\n    <SelectPrimitive.Portal>\n      <SelectPrimitive.Positioner\n        align={align}\n        alignItemWithTrigger={false}\n        alignOffset={alignOffset}\n        className=\"isolate z-50\"\n        side={side}\n        sideOffset={sideOffset}\n      >\n        <SelectPrimitive.Popup\n          className={cn(\n            lcdDisplayVariants({ appearance, size, variant }),\n            \"max-h-(--available-height) min-w-(--anchor-width) origin-(--transform-origin) overflow-y-auto rounded-md bg-(--lcd-display-bezel-edge) p-1 font-(family-name:--lcd-display-font) leading-none tracking-[0.12em] uppercase shadow-xl ring-1 ring-(--lcd-display-bezel-ring) transition-[opacity,scale] duration-100 outline-none data-ending-style:scale-95 data-ending-style:opacity-0 data-starting-style:scale-95 data-starting-style:opacity-0 motion-reduce:transition-none\",\n            className\n          )}\n          data-appearance={appearance}\n          data-slot=\"lcd-display-select-content\"\n          data-variant={variant}\n          ref={mergedRef}\n          {...props}\n        >\n          <LcdScreen\n            contentClassName=\"p-1\"\n            matrix={matrix}\n            scanlines={scanlines}\n          >\n            <SelectPrimitive.List>{children}</SelectPrimitive.List>\n          </LcdScreen>\n        </SelectPrimitive.Popup>\n      </SelectPrimitive.Positioner>\n    </SelectPrimitive.Portal>\n  );\n};\n\n/** One choice. Highlighted choices invert, like an LCD menu. */\nexport const LcdDisplaySelectItem = ({\n  className,\n  children,\n  ...props\n}: SelectPrimitive.Item.Props) => (\n  <SelectPrimitive.Item\n    className={cn(\n      \"flex cursor-default items-center gap-2 rounded-sm px-2 py-2 text-(--lcd-display-ink-dim) outline-none select-none data-disabled:opacity-40 data-highlighted:bg-(--lcd-display-lit) data-highlighted:text-(--lcd-display-glass) data-selected:text-(--lcd-display-lit) data-selected:data-highlighted:text-(--lcd-display-glass)\",\n      className\n    )}\n    data-slot=\"lcd-display-select-item\"\n    {...props}\n  >\n    {/* Keeps its width when hidden, so the choices stay aligned. */}\n    <span className=\"size-1.5 shrink-0\">\n      <SelectPrimitive.ItemIndicator\n        className=\"block size-full\"\n        data-slot=\"lcd-display-select-indicator\"\n      >\n        {/* A lit pixel instead of Base UI's default check mark. */}\n        <span className=\"block size-full bg-current\" />\n      </SelectPrimitive.ItemIndicator>\n    </span>\n    <SelectPrimitive.ItemText>{children}</SelectPrimitive.ItemText>\n  </SelectPrimitive.Item>\n);\n\nexport { lcdDisplayVariants };\nexport type { LcdDisplayAppearance, LcdDisplaySize, LcdDisplayVariant };\n",
      "type": "registry:ui"
    }
  ],
  "type": "registry:ui"
}