# scrollbar

Source: /tuil/docs/reference/packages/scroll/api/scrollbar
Locale: en

function exported by @mwillbanks/tuil-scroll.



{/* Generated by tooling/docs/generate-reference.ts. */}

## function [#function]

Public function exported by `@mwillbanks/tuil-scroll`.

```ts
export function scrollbar(
  viewportSize: number,
  extentSize: number,
  offset: number,
): { readonly start: number; readonly size: number };
```

## Members [#members]

This declaration has no public members.

## Parameters [#parameters]

| Member         | Type     | Required | Description                                    | Related types |
| -------------- | -------- | -------- | ---------------------------------------------- | ------------- |
| `viewportSize` | `number` | Yes      | Supplies the `viewportSize` value as `number`. | —             |
| `extentSize`   | `number` | Yes      | Supplies the `extentSize` value as `number`.   | —             |
| `offset`       | `number` | Yes      | Supplies the `offset` value as `number`.       | —             |

## Returns [#returns]

`{ readonly start: number; readonly size: number }` — Returns a value that satisfies `{ readonly start: number; readonly size: number }`.

Related types: —

## Throws [#throws]

No thrown errors are documented for this declaration.

## Related types [#related-types]

No package-local related types.

## Source [#source]

[View the secondary source reference](https://github.com/mwillbanks/tuil/blob/main/packages/scroll/src/index.ts)

## Package [#package]

[@mwillbanks/tuil-scroll](/tuil/docs/reference/packages/scroll)