Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | 2x 2x 2x 2x 2x 20x 19x 19x 19x 19x 19x 19x 2x 2x 2x 2x 2x 2x 17x 17x 17x 16x 16x 15x 15x 15x 15x 15x 15x 15x 15x 15x 15x 15x 1x 1x 25x 20x 25x 20x 19x 19x 16x 30x 24x 24x 24x 24x 24x | import { getScrollbarWidth, isBrowser, isIOS } from "./utils";
/**
* The subset of inline `document.body` styles this manager mutates while a lock
* is active. Saved verbatim when the first lock is acquired and written back
* exactly when the last lock is released, so any pre-existing inline styles the
* app had set are preserved.
*/
interface SavedBodyStyles {
overflow: string;
paddingRight: string;
position: string;
top: string;
left: string;
right: string;
width: string;
}
// ---------------------------------------------------------------------------
// Module-level state — shared across every useScrollLock instance in the app.
// This is what makes nested locks (e.g. two stacked modals) collapse into a
// single set of body styles, applied once and restored only when the count
// returns to zero.
// ---------------------------------------------------------------------------
let lockCount = 0;
let savedStyles: SavedBodyStyles | null = null;
let savedScrollX = 0;
let savedScrollY = 0;
let appliedIOSFix = false;
/**
* Save the current scroll position + inline body styles and apply the styles
* that prevent the body from scrolling. Called once, when the lock counter goes
* from 0 → 1.
*/
function applyBodyLock(): void {
if (!isBrowser()) return;
const body = document.body;
savedScrollX = window.scrollX;
savedScrollY = window.scrollY;
savedStyles = {
overflow: body.style.overflow,
paddingRight: body.style.paddingRight,
position: body.style.position,
top: body.style.top,
left: body.style.left,
right: body.style.right,
width: body.style.width,
};
appliedIOSFix = isIOS();
if (appliedIOSFix) {
// On iOS/Safari `overflow: hidden` does not stop touch scrolling, so pin the
// body in place with `position: fixed` offset by the current scroll. The
// offset is undone (and the scroll restored) in restoreBodyLock().
body.style.overflow = "hidden";
body.style.position = "fixed";
body.style.top = `-${savedScrollY}px`;
body.style.left = `-${savedScrollX}px`;
body.style.right = "0";
body.style.width = "100%";
} else {
// Everywhere else `overflow: hidden` is enough. Compensate for the vanished
// scrollbar with matching padding so the content doesn't jump sideways.
const scrollbarWidth = getScrollbarWidth();
body.style.overflow = "hidden";
if (scrollbarWidth > 0) {
body.style.paddingRight = `${scrollbarWidth}px`;
}
}
}
/**
* Restore the saved inline body styles (and, on iOS, the scroll position).
* Called once, when the lock counter goes from 1 → 0.
*/
function restoreBodyLock(): void {
if (!isBrowser()) return;
const body = document.body;
Eif (savedStyles) {
body.style.overflow = savedStyles.overflow;
body.style.paddingRight = savedStyles.paddingRight;
body.style.position = savedStyles.position;
body.style.top = savedStyles.top;
body.style.left = savedStyles.left;
body.style.right = savedStyles.right;
body.style.width = savedStyles.width;
savedStyles = null;
}
if (appliedIOSFix) {
// Undo the `position: fixed` jump by scrolling back to where we were.
window.scrollTo(savedScrollX, savedScrollY);
appliedIOSFix = false;
}
}
/**
* Increment the shared lock counter, applying the body-lock styles the first
* time the count leaves zero.
*/
export function lockBodyScroll(): void {
if (lockCount === 0) {
applyBodyLock();
}
lockCount += 1;
}
/**
* Decrement the shared lock counter, restoring the body once the last lock is
* released. Guards against dropping below zero so a stray unlock can never
* corrupt the counter.
*/
export function unlockBodyScroll(): void {
if (lockCount === 0) return;
lockCount -= 1;
if (lockCount === 0) {
restoreBodyLock();
}
}
/**
* The number of outstanding locks across all hook instances. Exposed for tests;
* intentionally **not** re-exported from the package's public entry point.
*/
export function getScrollLockCount(): number {
return lockCount;
}
/**
* Reset all module-level lock state. Test-only escape hatch — intentionally
* **not** re-exported from the package's public entry point.
*/
export function resetScrollLockState(): void {
lockCount = 0;
savedStyles = null;
savedScrollX = 0;
savedScrollY = 0;
appliedIOSFix = false;
}
|