androidx.compose.foundation.pager

Interfaces

`PageInfo`	This represents a single measured page in a `Pager` layout.	Cmn
`PageSize`	This is used to determine how Pages are laid out in `Pager`.	Cmn
`PagerLayoutInfo`	Contains useful information about the currently displayed layout state of a `Pager`.	Cmn
`PagerScope`	Receiver scope for `Pager`.	Cmn
`PagerSnapDistance`	`PagerSnapDistance` defines the way the `Pager` will treat the distance between the current page and the page where it will settle.	Cmn

Classes

`PageSize.Fixed`	Multiple pages in a viewport	Cmn
`PagerState`	The state that can be used to control `VerticalPager` and `HorizontalPager`	Cmn

Objects

`PageSize.Fill`	Pages take up the whole Pager size.	Cmn
`PagerDefaults`	Contains the default values used by `Pager`.	Cmn

Top-level functions summary

`Unit`	@Composable HorizontalPager( state: PagerState, modifier: Modifier, contentPadding: PaddingValues, pageSize: PageSize, beyondViewportPageCount: Int, pageSpacing: Dp, verticalAlignment: Alignment.Vertical, flingBehavior: TargetedFlingBehavior, userScrollEnabled: Boolean, reverseLayout: Boolean, key: ((index: Int) -> Any)?, pageNestedScrollConnection: NestedScrollConnection, snapPosition: SnapPosition, overscrollEffect: OverscrollEffect?, pageContent: @Composable PagerScope.(page: Int) -> Unit ) A Pager that scrolls horizontally.	Cmn
`LazyLayoutScrollScope`	`LazyLayoutScrollScope(state: PagerState, scrollScope: ScrollScope)` A `LazyLayoutScrollScope` that allows customization of animated scroll in `Pager`.	Cmn
`PagerState`	`PagerState( currentPage: Int, currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float, pageCount: () -> Int )` Creates a default `PagerState` to be used with a `Pager`	Cmn
`Unit`	@Composable VerticalPager( state: PagerState, modifier: Modifier, contentPadding: PaddingValues, pageSize: PageSize, beyondViewportPageCount: Int, pageSpacing: Dp, horizontalAlignment: Alignment.Horizontal, flingBehavior: TargetedFlingBehavior, userScrollEnabled: Boolean, reverseLayout: Boolean, key: ((index: Int) -> Any)?, pageNestedScrollConnection: NestedScrollConnection, snapPosition: SnapPosition, overscrollEffect: OverscrollEffect?, pageContent: @Composable PagerScope.(page: Int) -> Unit ) A Pager that scrolls vertically.	Cmn
`PagerState`	`@Composable rememberPagerState( initialPage: Int, initialPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float, pageCount: () -> Int )` Creates and remember a `PagerState` to be used with a `Pager`	Cmn

Top-level functions

Cmn

Artifact: androidx.compose.foundation:foundation

View Source

@Composable
fun HorizontalPager(
    state: PagerState,
    modifier: Modifier = Modifier,
    contentPadding: PaddingValues = PaddingValues(0.dp),
    pageSize: PageSize = PageSize.Fill,
    beyondViewportPageCount: Int = PagerDefaults.BeyondViewportPageCount,
    pageSpacing: Dp = 0.dp,
    verticalAlignment: Alignment.Vertical = Alignment.CenterVertically,
    flingBehavior: TargetedFlingBehavior = PagerDefaults.flingBehavior(state = state),
    userScrollEnabled: Boolean = true,
    reverseLayout: Boolean = false,
    key: ((index: Int) -> Any)? = null,
    pageNestedScrollConnection: NestedScrollConnection = PagerDefaults.pageNestedScrollConnection(state, Orientation.Horizontal),
    snapPosition: SnapPosition = SnapPosition.Start,
    overscrollEffect: OverscrollEffect? = rememberOverscrollEffect(),
    pageContent: @Composable PagerScope.(page: Int) -> Unit
): Unit

A Pager that scrolls horizontally. Pages are lazily placed in accordance to the available viewport size. By definition, pages in a Pager have the same size, defined by pageSize and use a snap animation (provided by flingBehavior to scroll pages into a specific position). You can use beyondViewportPageCount to place more pages before and after the visible pages.

If you need snapping with pages of different size, you can use a snapFlingBehavior with a SnapLayoutInfoProvider adapted to a LazyList.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
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.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

// Creates a 1-pager/viewport horizontal pager with single page snapping
val state = rememberPagerState { 10 }
HorizontalPager(
    state = state,
    modifier = Modifier.fillMaxSize(),
) { page ->
    Box(
        modifier =
            Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
        contentAlignment = Alignment.Center
    ) {
        Text(text = page.toString(), fontSize = 32.sp)
    }
}

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.offset
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.foundation.rememberScrollState
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.Text
import androidx.compose.material.TopAppBar
import androidx.compose.runtime.mutableStateOf
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.input.nestedscroll.NestedScrollConnection
import androidx.compose.ui.input.nestedscroll.NestedScrollSource
import androidx.compose.ui.input.nestedscroll.nestedScroll
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.dp

// This is a sample using NestedScroll and Pager.
// We use the toolbar offset changing example from
// androidx.compose.ui.samples.NestedScrollConnectionSample

val pagerState = rememberPagerState { 10 }

val toolbarHeight = 48.dp
val toolbarHeightPx = with(LocalDensity.current) { toolbarHeight.roundToPx().toFloat() }
val toolbarOffsetHeightPx = remember { mutableStateOf(0f) }
val nestedScrollConnection = remember {
    object : NestedScrollConnection {
        override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
            val delta = available.y
            val newOffset = toolbarOffsetHeightPx.value + delta
            toolbarOffsetHeightPx.value = newOffset.coerceIn(-toolbarHeightPx, 0f)
            return Offset.Zero
        }
    }
}

Box(modifier = Modifier.fillMaxSize().nestedScroll(nestedScrollConnection)) {
    TopAppBar(
        modifier =
            Modifier.height(toolbarHeight).offset {
                IntOffset(x = 0, y = toolbarOffsetHeightPx.value.roundToInt())
            },
        title = { Text("Toolbar offset is ${toolbarOffsetHeightPx.value}") }
    )

    val paddingOffset =
        toolbarHeight + with(LocalDensity.current) { toolbarOffsetHeightPx.value.toDp() }

    HorizontalPager(
        modifier = Modifier.fillMaxSize(),
        state = pagerState,
        contentPadding = PaddingValues(top = paddingOffset)
    ) {
        Column(modifier = Modifier.fillMaxWidth().verticalScroll(rememberScrollState())) {
            repeat(20) {
                Box(
                    modifier =
                        Modifier.fillMaxWidth()
                            .height(64.dp)
                            .padding(4.dp)
                            .background(if (it % 2 == 0) Color.Black else Color.Yellow),
                    contentAlignment = Alignment.Center
                ) {
                    Text(
                        text = it.toString(),
                        color = if (it % 2 != 0) Color.Black else Color.Yellow
                    )
                }
            }
        }
    }
}

Parameters
`state: PagerState`	The state to control this pager
`modifier: Modifier = Modifier`	A modifier instance to be applied to this Pager outer layout
`contentPadding: PaddingValues = PaddingValues(0.dp)`	a padding around the whole content. This will add padding for the content after it has been clipped, which is not possible via `modifier` param. You can use it to add a padding before the first page or after the last one. Use `pageSpacing` to add spacing between the pages.
`pageSize: PageSize = PageSize.Fill`	Use this to change how the pages will look like inside this pager.
`beyondViewportPageCount: Int = PagerDefaults.BeyondViewportPageCount`	Pages to compose and layout before and after the list of visible pages. Note: Be aware that using a large value for `beyondViewportPageCount` will cause a lot of pages to be composed, measured and placed which will defeat the purpose of using lazy loading. This should be used as an optimization to pre-load a couple of pages before and after the visible ones. This does not include the pages automatically composed and laid out by the pre-fetcher in the direction of the scroll during scroll events.
`pageSpacing: Dp = 0.dp`	The amount of space to be used to separate the pages in this Pager
`verticalAlignment: Alignment.Vertical = Alignment.CenterVertically`	How pages are aligned vertically in this Pager.
`flingBehavior: TargetedFlingBehavior = PagerDefaults.flingBehavior(state = state)`	The `TargetedFlingBehavior` to be used for post scroll gestures.
`userScrollEnabled: Boolean = true`	whether the scrolling via the user gestures or accessibility actions is allowed. You can still scroll programmatically using `PagerState.scroll` even when it is disabled.
`reverseLayout: Boolean = false`	reverse the direction of scrolling and layout.
`key: ((index: Int) -> Any)? = null`	a stable and unique key representing the item. When you specify the key the scroll position will be maintained based on the key, which means if you add/remove items before the current visible item the item with the given key will be kept as the first visible one. If null is passed the position in the list will represent the key.
`pageNestedScrollConnection: NestedScrollConnection = PagerDefaults.pageNestedScrollConnection(state, Orientation.Horizontal)`	A `NestedScrollConnection` that dictates how this `Pager` behaves with nested lists. The default behavior will see `Pager` to consume all nested deltas.
`snapPosition: SnapPosition = SnapPosition.Start`	The calculation of how this Pager will perform snapping of pages. Use this to provide different settling to different positions in the layout. This is used by `Pager` as a way to calculate `PagerState.currentPage`, currentPage is the page closest to the snap position in the layout (e.g. if the snap position is the start of the layout, then currentPage will be the page closest to that).
`overscrollEffect: OverscrollEffect? = rememberOverscrollEffect()`	the `OverscrollEffect` that will be used to render overscroll for this Pager. Note that the `OverscrollEffect.node` will be applied internally as well - you do not need to use Modifier.overscroll separately.
`pageContent: @Composable PagerScope.(page: Int) -> Unit`	This Pager's page Composable.

See also
`SnapLayoutInfoProvider`	for the implementation of a `SnapLayoutInfoProvider` that uses `androidx.compose.foundation.lazy.LazyListState`. Please refer to the samples to learn how to use this API.

Parameters
`state: PagerState`	The `PagerState` associated with the layout where this animated scroll should be performed.
`scrollScope: ScrollScope`	The base `ScrollScope` where the scroll session was created.

Returns
`LazyLayoutScrollScope`	An implementation of `LazyLayoutScrollScope` that works with `HorizontalPager` and `VerticalPager`.

PagerState

Cmn

Artifact: androidx.compose.foundation:foundation

View Source

Added in 1.7.0

fun PagerState(
    currentPage: Int = 0,
    currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f,
    pageCount: () -> Int
): PagerState

Creates a default PagerState to be used with a Pager

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.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.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

// You can use PagerState to define an initial page
val state = rememberPagerState(initialPage = 5) { 10 }
HorizontalPager(modifier = Modifier.fillMaxSize(), 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)
    }
}

Parameters
`currentPage: Int = 0`	The pager that should be shown first.
`currentPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f`	The offset of the initial page as a fraction of the page size. This should vary between -0.5 and 0.5 and indicates how to offset the initial page from the snapped position.
`pageCount: () -> Int`	The amount of pages this Pager will have.

Cmn

Artifact: androidx.compose.foundation:foundation

View Source

@Composable
fun VerticalPager(
    state: PagerState,
    modifier: Modifier = Modifier,
    contentPadding: PaddingValues = PaddingValues(0.dp),
    pageSize: PageSize = PageSize.Fill,
    beyondViewportPageCount: Int = PagerDefaults.BeyondViewportPageCount,
    pageSpacing: Dp = 0.dp,
    horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
    flingBehavior: TargetedFlingBehavior = PagerDefaults.flingBehavior(state = state),
    userScrollEnabled: Boolean = true,
    reverseLayout: Boolean = false,
    key: ((index: Int) -> Any)? = null,
    pageNestedScrollConnection: NestedScrollConnection = PagerDefaults.pageNestedScrollConnection(state, Orientation.Vertical),
    snapPosition: SnapPosition = SnapPosition.Start,
    overscrollEffect: OverscrollEffect? = rememberOverscrollEffect(),
    pageContent: @Composable PagerScope.(page: Int) -> Unit
): Unit

A Pager that scrolls vertically. Pages are lazily placed in accordance to the available viewport size. By definition, pages in a Pager have the same size, defined by pageSize and use a snap animation (provided by flingBehavior to scroll pages into a specific position). You can use beyondViewportPageCount to place more pages before and after the visible pages.

If you need snapping with pages of different size, you can use a snapFlingBehavior with a SnapLayoutInfoProvider adapted to a LazyList.

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
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.PagerState
import androidx.compose.foundation.pager.VerticalPager
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.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

// Creates a 1-pager/viewport vertical pager with single page snapping
val state = rememberPagerState { 10 }
VerticalPager(state = state, modifier = Modifier.fillMaxSize()) { page ->
    Box(
        modifier =
            Modifier.padding(10.dp).background(Color.Blue).fillMaxWidth().aspectRatio(1f),
        contentAlignment = Alignment.Center
    ) {
        Text(text = page.toString(), fontSize = 32.sp)
    }
}

Parameters
`state: PagerState`	The state to control this pager
`modifier: Modifier = Modifier`	A modifier instance to be apply to this Pager outer layout
`contentPadding: PaddingValues = PaddingValues(0.dp)`	a padding around the whole content. This will add padding for the content after it has been clipped, which is not possible via `modifier` param. You can use it to add a padding before the first page or after the last one. Use `pageSpacing` to add spacing between the pages.
`pageSize: PageSize = PageSize.Fill`	Use this to change how the pages will look like inside this pager.
`beyondViewportPageCount: Int = PagerDefaults.BeyondViewportPageCount`	Pages to compose and layout before and after the list of visible pages. Note: Be aware that using a large value for `beyondViewportPageCount` will cause a lot of pages to be composed, measured and placed which will defeat the purpose of using lazy loading. This should be used as an optimization to pre-load a couple of pages before and after the visible ones. This does not include the pages automatically composed and laid out by the pre-fetcher in * the direction of the scroll during scroll events.
`pageSpacing: Dp = 0.dp`	The amount of space to be used to separate the pages in this Pager
`horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally`	How pages are aligned horizontally in this Pager.
`flingBehavior: TargetedFlingBehavior = PagerDefaults.flingBehavior(state = state)`	The `TargetedFlingBehavior` to be used for post scroll gestures.
`userScrollEnabled: Boolean = true`	whether the scrolling via the user gestures or accessibility actions is allowed. You can still scroll programmatically using `PagerState.scroll` even when it is disabled.
`reverseLayout: Boolean = false`	reverse the direction of scrolling and layout.
`key: ((index: Int) -> Any)? = null`	a stable and unique key representing the item. When you specify the key the scroll position will be maintained based on the key, which means if you add/remove items before the current visible item the item with the given key will be kept as the first visible one. If null is passed the position in the list will represent the key.
`pageNestedScrollConnection: NestedScrollConnection = PagerDefaults.pageNestedScrollConnection(state, Orientation.Vertical)`	A `NestedScrollConnection` that dictates how this `Pager` behaves with nested lists. The default behavior will see `Pager` to consume all nested deltas.
`snapPosition: SnapPosition = SnapPosition.Start`	The calculation of how this Pager will perform snapping of Pages. Use this to provide different settling to different positions in the layout. This is used by `Pager` as a way to calculate `PagerState.currentPage`, currentPage is the page closest to the snap position in the layout (e.g. if the snap position is the start of the layout, then currentPage will be the page closest to that).
`overscrollEffect: OverscrollEffect? = rememberOverscrollEffect()`	the `OverscrollEffect` that will be used to render overscroll for this Pager. Note that the `OverscrollEffect.node` will be applied internally as well - you do not need to use Modifier.overscroll separately.
`pageContent: @Composable PagerScope.(page: Int) -> Unit`	This Pager's page Composable.

See also
`SnapLayoutInfoProvider`	for the implementation of a `SnapLayoutInfoProvider` that uses `androidx.compose.foundation.lazy.LazyListState`. Please refer to the sample to learn how to use this API.

rememberPagerState

Cmn

Artifact: androidx.compose.foundation:foundation

View Source

Added in 1.5.0

@Composable
fun rememberPagerState(
    initialPage: Int = 0,
    initialPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f,
    pageCount: () -> Int
): PagerState

Creates and remember a PagerState to be used with a Pager

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.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.graphics.Color
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.sp

// You can use PagerState to define an initial page
val state = rememberPagerState(initialPage = 5) { 10 }
HorizontalPager(modifier = Modifier.fillMaxSize(), 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)
    }
}

Parameters
`initialPage: Int = 0`	The pager that should be shown first.
`initialPageOffsetFraction: @FloatRange(from = -0.5, to = 0.5) Float = 0.0f`	The offset of the initial page as a fraction of the page size. This should vary between -0.5 and 0.5 and indicates how to offset the initial page from the snapped position.
`pageCount: () -> Int`	The amount of pages this Pager will have.

androidx.compose.foundation.pager

Interfaces

Classes

Objects

Top-level functions summary

Top-level functions

HorizontalPager

LazyLayoutScrollScope

PagerState

VerticalPager

rememberPagerState