# overscroll-behavior

> Applies `overscroll-behavior`, defaulting to `"contain"`: a scroll past the end stays inside this element and the platform affordance — iOS rubber-banding, Android pull-to-refresh — survives.

```ts
import { overscrollBehavior } from "@sdxc/u/overflow";
```

Applies `overscroll-behavior`, defaulting to `"contain"`: a scroll past the
end stays inside this element and the platform affordance — iOS
rubber-banding, Android pull-to-refresh — survives. `"none"` suppresses it.

## Quick reference

Every documented call, beside the CSS it emits.

| Call | CSS |
| --- | --- |
| `u.overscrollBehavior()` | `css({ overscrollBehavior: "contain" })` |
| `u.overscrollBehavior("none")` | `css({ overscrollBehavior: "none" })` |

## Examples

### Basic example

Use `overscrollBehavior()`, which applies `contain`, to stop a scroll that reaches the end of an element from carrying on to the page. Scroll to the bottom of the box and keep scrolling:

```tsx
<div mix={[scroll("y"), overscrollBehavior(), bs(24), is(72), maxIs("100%"), ...]}>
	<p mix={[...]}>
		This paragraph is taller than its box, so the last lines of it do not fit. Scroll to read
		the rest, while the page around the box stays exactly where it is.
	</p>
</div>
```

### Preventing the bounce

Use `overscrollBehavior("none")` to also suppress the bounce or pull-to-refresh at the edges, as in a full-screen canvas:

```tsx
<div
	mix={[scroll("y"), overscrollBehavior("none"), bs(24), is(72), maxIs("100%"), ...]}
>
	<p mix={[...]}>
		This paragraph is taller than its box, so the last lines of it do not fit. Scroll to read
		the rest, while the page around the box stays exactly where it is.
	</p>
</div>
```

### Chaining to the page

Use `overscrollBehavior("auto")` to restore the default, where a scroll past the end carries on to the page. Scroll to the bottom of the box and keep scrolling:

```tsx
<div
	mix={[scroll("y"), overscrollBehavior("auto"), bs(24), is(72), maxIs("100%"), ...]}
>
	<p mix={[...]}>
		This paragraph is taller than its box, so the last lines of it do not fit. Scroll to read
		the rest, while the page around the box stays exactly where it is.
	</p>
</div>
```

## Applying on a state

Wrap the call in a state utility to scope it to one selector.

```ts
u.hover(u.overscrollBehavior())
```

## Responsive design

Wrap the call in a container query to scope it to one width.

```ts
u.at("md", u.overscrollBehavior())
```

## Signature

```ts
u.overscrollBehavior(value?: OverscrollBehaviorValue)
```