{
  "$schema": "https://ui.shadcn.com/schema/registry-item.json",
  "name": "scroll-lock",
  "title": "Scroll Lock",
  "description": "Prevent body/element scrolling with reference counting",
  "dependencies": [],
  "registryDependencies": [],
  "files": [
    {
      "path": "src/hooks/use-scroll-lock.ts",
      "content": "\"use client\";\n\nimport { type RefObject, useEffect, useRef } from \"react\";\n\nconst lockCounts = new WeakMap<Element, number>();\nconst savedOverflow = new WeakMap<Element, string>();\nconst savedPaddingRight = new WeakMap<Element, string>();\n\n/** Options for preventing body or element scrolling. */\nexport interface UseScrollLockOptions {\n  /** Ref to the element to lock. Defaults to `document.body` when omitted. */\n  target?: RefObject<HTMLElement | null>;\n  /** Whether the scroll lock is active. */\n  enabled?: boolean;\n}\n\nfunction measureScrollbarWidth(el: HTMLElement): number {\n  const ownerDocument = el.ownerDocument;\n  const isViewport = el === ownerDocument.body || el === ownerDocument.scrollingElement;\n  if (isViewport) {\n    const view = ownerDocument.defaultView;\n    if (!view) return 0;\n    return view.innerWidth - ownerDocument.documentElement.clientWidth;\n  }\n  const style = ownerDocument.defaultView?.getComputedStyle(el);\n  const borderLeft = style ? Number.parseFloat(style.borderLeftWidth) || 0 : 0;\n  const borderRight = style ? Number.parseFloat(style.borderRightWidth) || 0 : 0;\n  return Math.max(0, el.offsetWidth - el.clientWidth - borderLeft - borderRight);\n}\n\nfunction lockElement(el: HTMLElement): () => void {\n  const count = lockCounts.get(el) ?? 0;\n\n  if (count === 0) {\n    savedOverflow.set(el, el.style.overflow);\n    savedPaddingRight.set(el, el.style.paddingRight);\n\n    const scrollbarWidth = measureScrollbarWidth(el);\n    if (scrollbarWidth > 0) {\n      const view = el.ownerDocument.defaultView;\n      const currentPaddingRight = view\n        ? Number.parseFloat(view.getComputedStyle(el).paddingRight) || 0\n        : 0;\n      el.style.paddingRight = `${currentPaddingRight + scrollbarWidth}px`;\n    }\n\n    el.style.overflow = \"hidden\";\n    el.setAttribute(\"data-scroll-locked\", \"\");\n  }\n  lockCounts.set(el, count + 1);\n\n  return () => {\n    const current = lockCounts.get(el) ?? 1;\n    const next = current - 1;\n    if (next <= 0) {\n      lockCounts.delete(el);\n      el.style.overflow = savedOverflow.get(el) ?? \"\";\n      el.style.paddingRight = savedPaddingRight.get(el) ?? \"\";\n      el.removeAttribute(\"data-scroll-locked\");\n      savedOverflow.delete(el);\n      savedPaddingRight.delete(el);\n    } else {\n      lockCounts.set(el, next);\n    }\n  };\n}\n\n// Effect-on-every-render is intentional: React does not re-fire effects when\n// target.current mutates while the ref object stays stable.\n/**\n * Locks scrolling by mutating the target element's overflow and padding, with\n * scrollbar-width compensation and shared reference counting. It installs no\n * event listeners.\n */\nexport function useScrollLock(options: UseScrollLockOptions = {}): void {\n  const { target, enabled = true } = options;\n  const lockedElementRef = useRef<HTMLElement | null>(null);\n  const releaseRef = useRef<(() => void) | null>(null);\n\n  // No dependency array on purpose; see hook-level comment above.\n  useEffect(() => {\n    let nextElement: HTMLElement | null = null;\n    if (enabled) {\n      nextElement = target ? target.current : document.body;\n    }\n    if (lockedElementRef.current === nextElement) return;\n\n    releaseRef.current?.();\n    releaseRef.current = null;\n    lockedElementRef.current = null;\n\n    if (!nextElement) return;\n\n    releaseRef.current = lockElement(nextElement);\n    lockedElementRef.current = nextElement;\n  });\n\n  useEffect(() => {\n    return () => {\n      releaseRef.current?.();\n      releaseRef.current = null;\n      lockedElementRef.current = null;\n    };\n  }, []);\n}\n",
      "type": "registry:hook",
      "target": "src/hooks/use-scroll-lock.ts"
    }
  ],
  "meta": {
    "client": true
  },
  "type": "registry:hook"
}