---
id: fast-animation.scrolltrigger
title: ScrollTrigger class
hide_title: true
---
<!-- Do not edit this file. It is automatically generated by API Documenter. -->

[@microsoft/fast-animation](./fast-animation.md) &gt; [ScrollTrigger](./fast-animation.scrolltrigger.md)

## ScrollTrigger class

Utility for registering element/callback pairs where the callback will be called on scroll while the element is in view.

<b>Signature:</b>

```typescript
export default class ScrollTrigger extends ScrollBase 
```

## Methods

|  Method | Modifiers | Description |
|  --- | --- | --- |
|  [update()](./fast-animation.scrolltrigger.update.md) |  | Check if elements are in view-port and apply scroll method if they are |
