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The state that can be used to control VerticalPager and HorizontalPager

Summary

Public constructors
PagerState(
    currentPage: Int,
    currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float
)
Cmn

Public functions
suspend Unit
animateScrollToPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float,
    animationSpec: AnimationSpec<Float>
)

Scroll animate to a given page's closest snap position.
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open Float

Dispatch scroll delta in pixels avoiding all scroll related mechanisms.
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Float

An utility function to help to calculate a given page's offset.
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Unit
requestScrollToPage(
    page: @IntRange(from = 0) Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float
)

Requests the page to be at the snapped position during the next remeasure, offset by pageOffsetFraction, and schedules a remeasure.
Cmn
open 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.
Cmn
suspend Unit
scrollToPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float
)

Scroll (jump immediately) to a given page.
Cmn
Unit
ScrollScope.updateCurrentPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float
)

Jump immediately to a given page with a given pageOffsetFraction inside a ScrollScope.
Cmn
Unit

Used to update targetPage during a programmatic scroll operation.
Cmn

Public properties
final Boolean

Whether this ScrollableState can scroll backward (consume a negative delta).
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final Boolean

Whether this ScrollableState can scroll forward (consume a positive delta).
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Int

The page that sits closest to the snapped position.
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Float

Indicates how far the current page is to the snapped position, this will vary from -0.5 (page is offset towards the start of the layout) to 0.5 (page is offset towards the end of the layout).
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InteractionSource

InteractionSource that will be used to dispatch drag events when this list is being dragged.
Cmn
open Boolean

Whether this ScrollableState is currently scrolling by gesture, fling or programmatically or not.
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open Boolean

The value of this property is true under the following scenarios, otherwise it's false.
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open Boolean

The value of this property is true under the following scenarios, otherwise it's false.
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PagerLayoutInfo

A PagerLayoutInfo that contains useful information about the Pager's last layout pass.
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abstract Int

The total amount of pages present in this pager.
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open ScrollIndicatorState?

ScrollIndicatorState used for drawing a scroll indicator (e.g., a scrollbar).
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Int

The page that is currently "settled".
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Int

The page this Pager intends to settle to.
Cmn

Public constructors

PagerState

Cmn
Added in 1.4.0
PagerState(
    currentPage: Int = 0,
    currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f
)
Parameters
currentPage: Int = 0

The initial page to be displayed
currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f

The offset of the initial page with respect to the start of the layout.

Public functions

animateScrollToPage

Cmn
Added in 1.4.0
suspend fun animateScrollToPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f,
    animationSpec: AnimationSpec<Float> = spring()
): Unit

Scroll animate to a given page's closest snap position. If the page is too far away from currentPage we will not compose all pages in the way. We will pre-jump to a nearer page, compose and animate the rest of the pages until page.

Please refer to the sample to learn how to use this API.

import androidx.compose.animation.core.animate
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val state = rememberPagerState { 10 }
val animationScope = rememberCoroutineScope()
Column {
    HorizontalPager(modifier = Modifier.weight(0.7f), state = state) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }

    Box(modifier = Modifier.weight(0.3f).fillMaxWidth(), contentAlignment = Alignment.Center) {
        Button(
            onClick = {
                animationScope.launch { state.animateScrollToPage(state.currentPage + 1) }
            }
        ) {
            Text(text = "Next Page")
        }
    }
}
Parameters
page: Int

The destination page to scroll to
pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f

A fraction of the page size that indicates the offset the destination page will be offset from its snapped position.
animationSpec: AnimationSpec<Float> = spring()

An AnimationSpec to move between pages. We'll use a spring as the default animation.

dispatchRawDelta

Cmn 
open fun dispatchRawDelta(delta: Float): Float

Dispatch scroll delta in pixels avoiding all scroll related mechanisms.

NOTE: unlike scroll, dispatching any delta with this method won't trigger nested scroll, won't stop ongoing scroll/drag animation and will bypass scrolling of any priority. This method will also ignore reverseDirection and other parameters set in scrollable.

This method is used internally for nested scrolling dispatch and other low level operations, allowing implementers of ScrollableState influence the consumption as suits them. Manually dispatching delta via this method will likely result in a bad user experience, you must prefer scroll method over this one.

Parameters
delta: Float

amount of scroll dispatched in the nested scroll process
Returns
Float

the amount of delta consumed

getOffsetDistanceInPages

Cmn
Added in 1.7.0
fun getOffsetDistanceInPages(page: Int): Float

An utility function to help to calculate a given page's offset. This is an offset that represents how far page is from the settled position (represented by currentPage offset). The difference here is that currentPageOffsetFraction is a value between -0.5 and 0.5 and the value calculated by this function can be larger than these numbers if page is different than currentPage.

For instance, if currentPage=0 and we call getOffsetDistanceInPages for page 3, the result will be 3, meaning the given page is 3 pages away from the current page (the sign represent the direction of the offset, positive is forward, negative is backwards). Another example is if currentPage=3 and we call getOffsetDistanceInPages for page 1, the result would be -2, meaning we're 2 pages away (moving backwards) to the current page.

This offset also works in conjunction with currentPageOffsetFraction, so if currentPage is out of its snapped position (i.e. currentPageOffsetFraction!=0) then the calculated value will still represent the offset in number of pages (in this case, not whole pages). For instance, if currentPage=1 and we're slightly offset, currentPageOffsetFraction=0.2, if we call this to page 2, the result would be 0.8, that is 0.8 page away from current page (moving forward).

Parameters
page: Int

The page to calculate the offset from. This should be between 0 and pageCount.
Returns
Float

The offset of page with respect to currentPage.

requestScrollToPage

Cmn
Added in 1.7.0
fun requestScrollToPage(
    page: @IntRange(from = 0) Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f
): Unit

Requests the page to be at the snapped position during the next remeasure, offset by pageOffsetFraction, and schedules a remeasure.

The scroll position will be updated to the requested position rather than maintain the index based on the current page key (when a data set change will also be applied during the next remeasure), but only for the next remeasure.

Any scroll in progress will be cancelled.

Parameters
page: @IntRange(from = 0) Int

the index to which to scroll. Must be non-negative.
pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f

the offset fraction that the page should end up after the scroll.

scroll

Cmn 
open suspend fun scroll(scrollPriority: MutatePriority, block: suspend ScrollScope.() -> Unit): Unit

Call this function to take control of scrolling and gain the ability to send scroll events via ScrollScope.scrollBy. All actions that change the logical scroll position must be performed within a scroll block (even if they don't call any other methods on this object) in order to guarantee that mutual exclusion is enforced.

If scroll is called from elsewhere with the scrollPriority higher or equal to ongoing scroll, ongoing scroll will be canceled.

scrollToPage

Cmn
Added in 1.4.0
suspend fun scrollToPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f
): Unit

Scroll (jump immediately) to a given page.

Please refer to the sample to learn how to use this API.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val state = rememberPagerState { 10 }
val scrollScope = rememberCoroutineScope()
Column {
    HorizontalPager(modifier = Modifier.height(400.dp), state = state) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }

    Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
        androidx.compose.material.Button(
            onClick = { scrollScope.launch { state.scrollToPage(state.currentPage + 1) } }
        ) {
            Text(text = "Next Page")
        }
    }
}
Parameters
page: Int

The destination page to scroll to
pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f

A fraction of the page size that indicates the offset the destination page will be offset from its snapped position.

updateCurrentPage

Cmn 
fun ScrollScope.updateCurrentPage(
    page: Int,
    pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f
): Unit

Jump immediately to a given page with a given pageOffsetFraction inside a ScrollScope. Use this method to create custom animated scrolling experiences. This will update the value of currentPage and currentPageOffsetFraction immediately, but can only be used inside a ScrollScope, use scroll to gain access to a ScrollScope.

Please refer to the sample to learn how to use this API.

import androidx.compose.animation.core.animate
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

suspend fun PagerState.customAnimateScrollToPage(page: Int) {
    val preJumpPosition =
        if (page > currentPage) {
            (page - 1).coerceAtLeast(0)
        } else {
            (page + 1).coerceAtMost(pageCount)
        }
    scroll {
        // Update the target page
        updateTargetPage(page)

        // pre-jump to 1 page before our target page
        updateCurrentPage(preJumpPosition, 0.0f)
        val targetPageDiff = page - currentPage
        val distance = targetPageDiff * layoutInfo.pageSize.toFloat()
        var previousValue = 0.0f
        animate(0f, distance) { currentValue, _ ->
            previousValue += scrollBy(currentValue - previousValue)
        }
    }
}

val state = rememberPagerState(initialPage = 5) { 10 }
val scope = rememberCoroutineScope()

Column {
    HorizontalPager(modifier = Modifier.fillMaxSize().weight(0.9f), state = state) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }

    Button(onClick = { scope.launch { state.customAnimateScrollToPage(1) } }) {
        Text(text = "Jump to Page 1")
    }
}
Parameters
page: Int

The destination page to scroll to
pageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f

A fraction of the page size that indicates the offset the destination page will be offset from its snapped position.

updateTargetPage

Cmn 
fun ScrollScope.updateTargetPage(targetPage: Int): Unit

Used to update targetPage during a programmatic scroll operation. This can only be called inside a ScrollScope and should be called anytime a custom scroll (through scroll) is executed in order to correctly update targetPage. This will not move the pages and it's still the responsibility of the caller to call ScrollScope.scrollBy in order to actually get to targetPage. By the end of the scroll block, when the Pager is no longer scrolling targetPage will assume the value of currentPage.

Please refer to the sample to learn how to use this API.

import androidx.compose.animation.core.animate
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

suspend fun PagerState.customAnimateScrollToPage(page: Int) {
    val preJumpPosition =
        if (page > currentPage) {
            (page - 1).coerceAtLeast(0)
        } else {
            (page + 1).coerceAtMost(pageCount)
        }
    scroll {
        // Update the target page
        updateTargetPage(page)

        // pre-jump to 1 page before our target page
        updateCurrentPage(preJumpPosition, 0.0f)
        val targetPageDiff = page - currentPage
        val distance = targetPageDiff * layoutInfo.pageSize.toFloat()
        var previousValue = 0.0f
        animate(0f, distance) { currentValue, _ ->
            previousValue += scrollBy(currentValue - previousValue)
        }
    }
}

val state = rememberPagerState(initialPage = 5) { 10 }
val scope = rememberCoroutineScope()

Column {
    HorizontalPager(modifier = Modifier.fillMaxSize().weight(0.9f), state = state) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }

    Button(onClick = { scope.launch { state.customAnimateScrollToPage(1) } }) {
        Text(text = "Jump to Page 1")
    }
}

Public properties

canScrollBackward

Cmn 
final val canScrollBackward: Boolean

Whether this ScrollableState can scroll backward (consume a negative delta). This is typically false if the scroll position is equal to its minimum value, and true otherwise.

Note that true here does not imply that delta will be consumed - the ScrollableState may decide not to handle the incoming delta (such as if it is already being scrolled separately). Additionally, for backwards compatibility with previous versions of ScrollableState this value defaults to true.

import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.material.Icon
import androidx.compose.material.Text
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.KeyboardArrowDown
import androidx.compose.material.icons.filled.KeyboardArrowUp
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.graphicsLayer

val state = rememberLazyListState()
Column(Modifier.fillMaxWidth(), horizontalAlignment = Alignment.CenterHorizontally) {
    Icon(
        Icons.Filled.KeyboardArrowUp,
        null,
        Modifier.graphicsLayer {
            // Hide the icon if we cannot scroll backward (we are the start of the list)
            // We use graphicsLayer here to control the alpha so that we only redraw when this
            // value changes, instead of recomposing
            alpha = if (state.canScrollBackward) 1f else 0f
        },
        Color.Red,
    )
    val items = (1..100).toList()
    LazyColumn(Modifier.weight(1f).fillMaxWidth(), state) {
        items(items) { Text("Item is $it") }
    }
    Icon(
        Icons.Filled.KeyboardArrowDown,
        null,
        Modifier.graphicsLayer {
            // Hide the icon if we cannot scroll forward (we are the end of the list)
            // We use graphicsLayer here to control the alpha so that we only redraw when this
            // value changes, instead of recomposing
            alpha = if (state.canScrollForward) 1f else 0f
        },
        Color.Red,
    )
}

canScrollForward

Cmn 
final val canScrollForward: Boolean

Whether this ScrollableState can scroll forward (consume a positive delta). This is typically false if the scroll position is equal to its maximum value, and true otherwise.

Note that true here does not imply that delta will be consumed - the ScrollableState may decide not to handle the incoming delta (such as if it is already being scrolled separately). Additionally, for backwards compatibility with previous versions of ScrollableState this value defaults to true.

import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.items
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.material.Icon
import androidx.compose.material.Text
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.KeyboardArrowDown
import androidx.compose.material.icons.filled.KeyboardArrowUp
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.graphicsLayer

val state = rememberLazyListState()
Column(Modifier.fillMaxWidth(), horizontalAlignment = Alignment.CenterHorizontally) {
    Icon(
        Icons.Filled.KeyboardArrowUp,
        null,
        Modifier.graphicsLayer {
            // Hide the icon if we cannot scroll backward (we are the start of the list)
            // We use graphicsLayer here to control the alpha so that we only redraw when this
            // value changes, instead of recomposing
            alpha = if (state.canScrollBackward) 1f else 0f
        },
        Color.Red,
    )
    val items = (1..100).toList()
    LazyColumn(Modifier.weight(1f).fillMaxWidth(), state) {
        items(items) { Text("Item is $it") }
    }
    Icon(
        Icons.Filled.KeyboardArrowDown,
        null,
        Modifier.graphicsLayer {
            // Hide the icon if we cannot scroll forward (we are the end of the list)
            // We use graphicsLayer here to control the alpha so that we only redraw when this
            // value changes, instead of recomposing
            alpha = if (state.canScrollForward) 1f else 0f
        },
        Color.Red,
    )
}

currentPage

Cmn
Added in 1.4.0
val currentPage: Int

The page that sits closest to the snapped position. This is an observable value and will change as the pager scrolls either by gesture or animation.

Please refer to the sample to learn how to use this API.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val pagerState = rememberPagerState { 10 }
Column(modifier = Modifier.fillMaxSize()) {
    HorizontalPager(modifier = Modifier.weight(0.9f), state = pagerState) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }
    Column(modifier = Modifier.weight(0.1f).fillMaxWidth()) {
        Text(text = "Current Page: ${pagerState.currentPage}")
        Text(text = "Current Page Offset Fraction: ${pagerState.currentPageOffsetFraction}")
        Text(text = "Target Page: ${pagerState.targetPage}")
        Text(text = "Settled Page Offset: ${pagerState.settledPage}")
    }
}

currentPageOffsetFraction

Cmn
Added in 1.4.0
val currentPageOffsetFraction: Float

Indicates how far the current page is to the snapped position, this will vary from -0.5 (page is offset towards the start of the layout) to 0.5 (page is offset towards the end of the layout). This is 0.0 if the currentPage is in the snapped position. The value will flip once the current page changes.

This property is observable and shouldn't be used as is in a composable function due to potential performance issues. To use it in the composition, please consider using a derived state (e.g derivedStateOf) to only have recompositions when the derived value changes.

Please refer to the sample to learn how to use this API.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val pagerState = rememberPagerState { 10 }
Column(modifier = Modifier.fillMaxSize()) {
    HorizontalPager(modifier = Modifier.weight(0.9f), state = pagerState) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }
    Column(modifier = Modifier.weight(0.1f).fillMaxWidth()) {
        Text(text = "Current Page: ${pagerState.currentPage}")
        Text(text = "Current Page Offset Fraction: ${pagerState.currentPageOffsetFraction}")
        Text(text = "Target Page: ${pagerState.targetPage}")
        Text(text = "Settled Page Offset: ${pagerState.settledPage}")
    }
}

interactionSource

Cmn
Added in 1.4.0
val interactionSource: InteractionSource

InteractionSource that will be used to dispatch drag events when this list is being dragged. If you want to know whether the fling (or animated scroll) is in progress, use isScrollInProgress.

isScrollInProgress

Cmn 
open val isScrollInProgress: Boolean

Whether this ScrollableState is currently scrolling by gesture, fling or programmatically or not.

lastScrolledBackward

Cmn 
open val lastScrolledBackward: Boolean

The value of this property is true under the following scenarios, otherwise it's false.

lastScrolledForward

Cmn 
open val lastScrolledForward: Boolean

The value of this property is true under the following scenarios, otherwise it's false.

layoutInfo

Cmn
Added in 1.6.0
val layoutInfo: PagerLayoutInfo

A PagerLayoutInfo that contains useful information about the Pager's last layout pass. For instance, you can query which pages are currently visible in the layout.

This property is observable and is updated after every scroll or remeasure. If you use it in the composable function it will be recomposed on every change causing potential performance issues including infinity recomposition loop. Therefore, avoid using it in the composition.

If you want to run some side effects like sending an analytics event or updating a state based on this value consider using "snapshotFlow":

import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.remember
import androidx.compose.runtime.snapshotFlow

val pagerState = rememberPagerState() { 10 }
LaunchedEffect(pagerState) {
    snapshotFlow { pagerState.layoutInfo.visiblePagesInfo.firstOrNull() }
        .collect {
            // use the new first visible page info
        }
}

pageCount

Cmn
Added in 1.5.0
abstract val pageCount: Int

The total amount of pages present in this pager. The source of this data should be observable.

scrollIndicatorState

Cmn 
open val scrollIndicatorState: ScrollIndicatorState?

ScrollIndicatorState used for drawing a scroll indicator (e.g., a scrollbar).

This property may be null if scroll indicators are not applicable or if the underlying scrollable component does not support or provide this state.

settledPage

Cmn
Added in 1.4.0
val settledPage: Int

The page that is currently "settled". This is an animation/gesture unaware page in the sense that it will not be updated while the pages are being scrolled, but rather when the animation/scroll settles.

Please refer to the sample to learn how to use this API.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val pagerState = rememberPagerState { 10 }
Column(modifier = Modifier.fillMaxSize()) {
    HorizontalPager(modifier = Modifier.weight(0.9f), state = pagerState) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }
    Column(modifier = Modifier.weight(0.1f).fillMaxWidth()) {
        Text(text = "Current Page: ${pagerState.currentPage}")
        Text(text = "Current Page Offset Fraction: ${pagerState.currentPageOffsetFraction}")
        Text(text = "Target Page: ${pagerState.targetPage}")
        Text(text = "Settled Page Offset: ${pagerState.settledPage}")
    }
}

targetPage

Cmn
Added in 1.4.0
val targetPage: Int

The page this Pager intends to settle to. During fling or animated scroll (from animateScrollToPage this will represent the page this pager intends to settle to. When no scroll is ongoing, this will be equal to currentPage.

Please refer to the sample to learn how to use this API.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.aspectRatio
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.pager.HorizontalPager
import androidx.compose.foundation.pager.PagerState
import androidx.compose.foundation.pager.rememberPagerState
import androidx.compose.material.Text
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

val pagerState = rememberPagerState { 10 }
Column(modifier = Modifier.fillMaxSize()) {
    HorizontalPager(modifier = Modifier.weight(0.9f), state = pagerState) { page ->
        Box(
            modifier =
                Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
            contentAlignment = Alignment.Center,
        ) {
            Text(text = page.toString(), fontSize = 32.sp)
        }
    }
    Column(modifier = Modifier.weight(0.1f).fillMaxWidth()) {
        Text(text = "Current Page: ${pagerState.currentPage}")
        Text(text = "Current Page Offset Fraction: ${pagerState.currentPageOffsetFraction}")
        Text(text = "Target Page: ${pagerState.targetPage}")
        Text(text = "Settled Page Offset: ${pagerState.settledPage}")
    }
}
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