fix: #550

docs/useLockBodyScroll.md

@@ -2,7 +2,12 @@
 
 React side-effect hook that locks scrolling on the body element. Useful for modal and other overlay components.
 
-## Usage
+Accepts ref object pointing to any HTML element as second parameter. Parent body element will be found and it's scroll will be locked/unlocked. It is needed to proper iFrame handling.  
+By default it uses body element of script's parent window. 
+
+>Note: To improve performance you can pass body's or iframe's ref object, thus no parent lookup will be performed 
+
+## Usage 
 
 ```jsx
 import {useLockBodyScroll, useToggle} from 'react-use';
@@ -25,7 +30,8 @@ const Demo = () => {
 ## Reference
 
 ```ts
-useLockBodyScroll(enabled?: boolean = true);
+useLockBodyScroll(locked: boolean = true, elementRef?: RefObject<HTMLElement>);
 ```
 
-- `enabled` &mdash; Hook will lock scrolling on the body element if `true`, defaults to `true`
+- `locked` &mdash; Hook will lock scrolling on the body element if `true`, defaults to `true`
+- `elementRef` &mdash; The element ref object to find the body element. Can be either a ref to body or iframe element.

package.json

@@ -89,6 +89,7 @@
     "raf-stub": "3.0.0",
     "react": "16.9.0",
     "react-dom": "16.9.0",
+    "react-frame-component": "^4.1.1",
     "react-spring": "8.0.27",
     "react-test-renderer": "16.9.0",
     "rebound": "0.1.0",

src/__stories__/useLockBodyScroll.story.tsx

@@ -1,5 +1,7 @@
 import { storiesOf } from '@storybook/react';
 import * as React from 'react';
+import { useRef } from 'react';
+import Frame from 'react-frame-component';
 import { useLockBodyScroll, useToggle } from '..';
 import ShowDocs from './util/ShowDocs';
 
@@ -27,12 +29,38 @@ const AnotherComponent = () => {
   );
 };
 
+const IframeComponent = () => {
+  const [mainLocked, toggleMainLocked] = useToggle(false);
+  const [iframeLocked, toggleIframeLocked] = useToggle(false);
+  const iframeElementRef = useRef<HTMLIFrameElement>(null);
+
+  useLockBodyScroll(mainLocked);
+  useLockBodyScroll(iframeLocked, iframeElementRef);
+
+  return (
+    <div style={{ height: '200vh' }}>
+      <Frame style={{ height: '50vh', width: '50vw' }}>
+        <div style={{ height: '200vh' }} ref={iframeElementRef}>
+          <button onClick={() => toggleMainLocked()} style={{ position: 'fixed', left: 0, top: 0 }}>
+            {mainLocked ? 'Unlock' : 'Lock'} main window scroll
+          </button>
+          <button onClick={() => toggleIframeLocked()} style={{ position: 'fixed', left: 0, top: 64 }}>
+            {iframeLocked ? 'Unlock' : 'Lock'} iframe window scroll
+          </button>
+        </div>
+      </Frame>
+    </div>
+  );
+};
+
 storiesOf('Side effects|useLockBodyScroll', module)
   .add('Docs', () => <ShowDocs md={require('../../docs/useLockBodyScroll.md')} />)
   .add('Demo', () => <Demo />)
   .add('Two hooks on page', () => (
     <>
       <AnotherComponent />
       <Demo />
+      <IframeComponent />
     </>
-  ));
+  ))
+  .add('Iframe', () => <IframeComponent />);

src/useLockBodyScroll.ts

@@ -1,34 +1,58 @@
-import { useEffect } from 'react';
+import { RefObject, useEffect, useRef } from 'react';
 
-let counter = 0;
-let originalOverflow: string | null = null;
+export function getClosestBody(el: Element | HTMLElement | HTMLIFrameElement | null): HTMLElement | null {
+  if (!el) {
+    return null;
+  } else if (el.tagName === 'BODY') {
+    return el as HTMLElement;
+  } else if (el.tagName === 'IFRAME') {
+    const document = (el as HTMLIFrameElement).contentDocument;
+    return document ? document.body : null;
+  } else if (!(el as HTMLElement).offsetParent) {
+    return null;
+  }
 
-const lock = () => {
-  originalOverflow = window.getComputedStyle(document.body).overflow;
-  document.body.style.overflow = 'hidden';
-};
+  return getClosestBody((el as HTMLElement).offsetParent!);
+}
 
-const unlock = () => {
-  document.body.style.overflow = originalOverflow;
-  originalOverflow = null;
-};
+export interface BodyInfoItem {
+  counter: number;
+  initialOverflow: string | null;
+}
 
-const increment = () => {
-  counter++;
-  if (counter === 1) {
-    lock();
-  }
-};
+const bodies: Map<HTMLElement, BodyInfoItem> = new Map();
 
-const decrement = () => {
-  counter--;
-  if (counter === 0) {
-    unlock();
-  }
-};
+const doc: Document | undefined = typeof document === 'object' ? document : undefined;
+
+export default !doc
+  ? function useLockBodyMock(_locked: boolean = true, _elementRef?: RefObject<HTMLElement>) {}
+  : function useLockBody(locked: boolean = true, elementRef?: RefObject<HTMLElement>) {
+      elementRef = elementRef || useRef(doc!.body);
+
+      useEffect(() => {
+        const body = getClosestBody(elementRef!.current);
+        if (!body) {
+          return;
+        }
 
-const useLockBodyScroll = (enabled: boolean = true) => {
-  useEffect(() => (enabled ? (increment(), decrement) : undefined), [enabled]);
-};
+        const bodyInfo = bodies.get(body);
 
-export default useLockBodyScroll;
+        if (locked) {
+          if (!bodyInfo) {
+            bodies.set(body, { counter: 1, initialOverflow: body.style.overflow });
+            body.style.overflow = 'hidden';
+          } else {
+            bodies.set(body, { counter: bodyInfo.counter + 1, initialOverflow: bodyInfo.initialOverflow });
+          }
+        } else {
+          if (bodyInfo) {
+            if (bodyInfo.counter === 1) {
+              bodies.delete(body);
+              body.style.overflow = bodyInfo.initialOverflow;
+            } else {
+              bodies.set(body, { counter: bodyInfo.counter - 1, initialOverflow: bodyInfo.initialOverflow });
+            }
+          }
+        }
+      }, [locked, elementRef.current]);
+    };

yarn.lock

@@ -10140,6 +10140,11 @@ react-focus-lock@^1.18.3:
     prop-types "^15.6.2"
     react-clientside-effect "^1.2.0"
 
+react-frame-component@^4.1.1:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/react-frame-component/-/react-frame-component-4.1.1.tgz#ea8f7c518ef6b5ad72146dd1f648752369826894"
+  integrity sha512-NfJp90AvYA1R6+uSYafQ+n+UM2HjHqi4WGHeprVXa6quU9d8o6ZFRzQ36uemY82dlkZFzf2jigFx6E4UzNFajA==
+
 react-helmet-async@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/react-helmet-async/-/react-helmet-async-1.0.2.tgz#bb55dd8268f7b15aac69c6b22e2f950abda8cc44"