ScrollState

Kotlin |Java

@Stable class ScrollState : ScrollableState

kotlin.Any
↳	androidx.compose.foundation.ScrollState

State of the scroll. Allows the developer to change the scroll position or get current state by calling methods on this object. To be hosted and passed to Modifier.verticalScroll or Modifier.horizontalScroll

To create and automatically remember ScrollState with default parameters use rememberScrollState.

Learn how to control the state of Modifier.verticalScroll or Modifier.horizontalScroll:

import androidx.compose.foundation.gestures.scrollBy
import androidx.compose.foundation.gestures.animateScrollBy
import androidx.compose.foundation.horizontalScroll
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.rememberScrollState
import androidx.compose.material.Text
import androidx.compose.runtime.rememberCoroutineScope

// Create ScrollState to own it and be able to control scroll behaviour of scrollable Row below
val scrollState = rememberScrollState()
val scope = rememberCoroutineScope()
Column {
    Row(Modifier.horizontalScroll(scrollState)) {
        repeat(1000) { index ->
            Square(index)
        }
    }
    // Controls for scrolling
    Row(verticalAlignment = Alignment.CenterVertically) {
        Text("Scroll")
        Button(
            onClick = {
                scope.launch { scrollState.scrollTo(scrollState.value - 1000) }
            }
        ) {
            Text("< -")
        }
        Button(
            onClick = {
                scope.launch { scrollState.scrollBy(10000f) }
            }
        ) {
            Text("--- >")
        }
    }
    Row(verticalAlignment = Alignment.CenterVertically) {
        Text("Smooth Scroll")
        Button(
            onClick = {
                scope.launch { scrollState.animateScrollTo(scrollState.value - 1000) }
            }
        ) {
            Text("< -")
        }
        Button(
            onClick = {
                scope.launch { scrollState.animateScrollBy(10000f) }
            }
        ) {
            Text("--- >")
        }
    }
}

Summary

Public constructors
`<init>(initial: Int)` State of the scroll.

Public methods
suspend Unit	`animateScrollTo(value: Int, animationSpec: AnimationSpec<Float> = SpringSpec())` Scroll to position in pixels with animation.
Float	`dispatchRawDelta(delta: Float)` Dispatch scroll delta in pixels avoiding all scroll related mechanisms.
suspend Unit	`scroll(scrollPriority: MutatePriority, block: suspend ScrollScope.() -> Unit)` Call this function to take control of scrolling and gain the ability to send scroll events via ScrollScope.scrollBy.
suspend Float	`scrollTo(value: Int)` Instantly jump to the given position in pixels.

Inherited extension functions

From androidx.compose.foundation.gestures

suspend Float	`ScrollableState.animateScrollBy(value: Float, animationSpec: AnimationSpec<Float> = spring())` Scroll by value pixels with animation.
suspend Float	`ScrollableState.scrollBy(value: Float)` Jump instantly by value pixels.
suspend Unit	`ScrollableState.stopScroll(scrollPriority: MutatePriority = MutatePriority.Default)` Stop and suspend until any ongoing animation, smooth scrolling, fling, or any other scroll occurring via ScrollableState.scroll is terminated.

Properties
InteractionSource	`interactionSource` InteractionSource that will be used to dispatch drag events when this list is being dragged.
Boolean	`isScrollInProgress` Whether this ScrollableState is currently scrolling by gesture, fling or programmatically or not.
Int	`maxValue` maximum bound for value, or Int.MAX_VALUE if still unknown
Int	`value` current scroll position value in pixels

Companion properties
Saver<ScrollState, *>	`Saver` The default Saver implementation for ScrollState.

Public constructors

<init>

ScrollState(initial: Int)

To create and automatically remember ScrollState with default parameters use rememberScrollState.

Learn how to control the state of Modifier.verticalScroll or Modifier.horizontalScroll:

import androidx.compose.foundation.gestures.scrollBy
import androidx.compose.foundation.gestures.animateScrollBy
import androidx.compose.foundation.horizontalScroll
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.rememberScrollState
import androidx.compose.material.Text
import androidx.compose.runtime.rememberCoroutineScope

// Create ScrollState to own it and be able to control scroll behaviour of scrollable Row below
val scrollState = rememberScrollState()
val scope = rememberCoroutineScope()
Column {
    Row(Modifier.horizontalScroll(scrollState)) {
        repeat(1000) { index ->
            Square(index)
        }
    }
    // Controls for scrolling
    Row(verticalAlignment = Alignment.CenterVertically) {
        Text("Scroll")
        Button(
            onClick = {
                scope.launch { scrollState.scrollTo(scrollState.value - 1000) }
            }
        ) {
            Text("< -")
        }
        Button(
            onClick = {
                scope.launch { scrollState.scrollBy(10000f) }
            }
        ) {
            Text("--- >")
        }
    }
    Row(verticalAlignment = Alignment.CenterVertically) {
        Text("Smooth Scroll")
        Button(
            onClick = {
                scope.launch { scrollState.animateScrollTo(scrollState.value - 1000) }
            }
        ) {
            Text("< -")
        }
        Button(
            onClick = {
                scope.launch { scrollState.animateScrollBy(10000f) }
            }
        ) {
            Text("--- >")
        }
    }
}

Parameters
initial: Int	value of the scroll

Public methods

animateScrollTo

suspend fun animateScrollTo(
    value: Int, 
    animationSpec: AnimationSpec<Float