---
title: "ScrollIndicatorState"
description: "Represents the state required to draw a scroll indicator (e.g., a scrollbar), which is typically
provided by a scrollable component.

For scrollable components with a large number of items, such as lazy layouts, implementations may
need to provide a reasonable heuristic for properties like [scrollOffset] and [contentSize], as
calculating the exact value might be computationally expensive or impossible."
type: "interface"
---

<div class='type'>Interface</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>



```kotlin
interface ScrollIndicatorState
```


Represents the state required to draw a scroll indicator (e.g., a scrollbar), which is typically
provided by a scrollable component.

For scrollable components with a large number of items, such as lazy layouts, implementations may
need to provide a reasonable heuristic for properties like `scrollOffset` and `contentSize`, as
calculating the exact value might be computationally expensive or impossible.


## Properties

<div class='sourceset sourceset-common'>Common</div>


```kotlin
@get:FrequentlyChangingValue @get:IntRange(from = 0) val scrollOffset: Int
```


The current scroll offset of the content from the start, typically in pixels.

For a vertical scrollable component, this is the Y offset. For a horizontal scrollable
component, this is the X offset.

For lazy layouts, this value may represent an estimated scroll offset.

Implementations should return `Int.MAX_VALUE` if this value is not yet known.



<div class='sourceset sourceset-common'>Common</div>


```kotlin
@get:IntRange(from = 0) val contentSize: Int
```


The total size of the scrollable content, typically in pixels.

For a vertical scrollable component, this is the total height of the content. For a
horizontal scrollable component, this is the total width of the content.

For lazy layouts, this value may represent an estimated total size of content, and may change
as `scrollOffset` changes.

The scroll range (how far the content can scroll) can be determined by subtracting the
`viewportSize` from this `contentSize`.

Implementations should return `Int.MAX_VALUE` if this value is not yet known.



<div class='sourceset sourceset-common'>Common</div>


```kotlin
@get:IntRange(from = 0) val viewportSize: Int
```


The size of the visible portion of the scrollable content, typically in pixels.

For a vertical scrollable component, this is the height of the viewport. For a horizontal
scrollable component, this is the width of the viewport.

Implementations should return `Int.MAX_VALUE` if this value is not yet known.