viewpager2/androidx.viewpager2.widget/ViewPager2

ViewPager2

class ViewPager2 : ViewGroup(source)

ViewPager2 replaces androidx.viewpager.widget.ViewPager, addressing most of its predecessor’s pain-points, including right-to-left layout support, vertical orientation, modifiable Fragment collections, etc.

A note on WindowInsets: due to a bug in API 29 and before, WindowInsets were incorrectly dispatched to a View's children and siblings. ViewPager2 offers a fix to make sure that all pages receive the correct insets, but it comes at the cost of not dispatching insets to any siblings of ViewPager2 or siblings of its ancestors that haven't received the insets yet. If you want to handle insets on each page separately (instead of on ViewPager2 or one of its parents), you should install a WindowInsetsApplier by calling WindowInsetsApplier.install(viewPager2). If you don't handle insets on any of the pages, we recommend you don't use the WindowInsetsApplier.

See also

Constructors

constructor(@NonNull context: Context)

constructor(@NonNull context: Context, @Nullable attrs: AttributeSet)

constructor(@NonNull context: Context, @Nullable attrs: AttributeSet, defStyleAttr: Int)

@RequiresApi(value = 21)

constructor(@NonNull context: Context, @Nullable attrs: AttributeSet, defStyleAttr: Int, defStyleRes: Int)

Types

OffscreenPageLimit

@RestrictTo(value = LIBRARY_GROUP_PREFIX)

@Retention(value = SOURCE)

@IntRange(from = 1)

annotation class OffscreenPageLimit

OnPageChangeCallback

abstract class OnPageChangeCallback

Callback interface for responding to changing state of the selected page.

@RestrictTo(value = LIBRARY_GROUP_PREFIX)

@Retention(value = SOURCE)

annotation class Orientation

PageTransformer

interface PageTransformer

A PageTransformer is invoked whenever a visible/attached page is scrolled.

@RestrictTo(value = LIBRARY_GROUP_PREFIX)

@Retention(value = SOURCE)

annotation class ScrollState

Properties

OFFSCREEN_PAGE_LIMIT_DEFAULT

val OFFSCREEN_PAGE_LIMIT_DEFAULT: Int = -1

Value to indicate that the default caching mechanism of RecyclerView should be used instead of explicitly prefetch and retain pages to either side of the current page.

ORIENTATION_HORIZONTAL

val ORIENTATION_HORIZONTAL: Int = 0

ORIENTATION_VERTICAL

val ORIENTATION_VERTICAL: Int = 1

SCROLL_STATE_DRAGGING

val SCROLL_STATE_DRAGGING: Int = 1

Indicates that the ViewPager2 is currently being dragged by the user, or programmatically via fake drag functionality.

SCROLL_STATE_IDLE

val SCROLL_STATE_IDLE: Int = 0

Indicates that the ViewPager2 is in an idle, settled state.

SCROLL_STATE_SETTLING

val SCROLL_STATE_SETTLING: Int = 2

Indicates that the ViewPager2 is in the process of settling to a final position.

Functions

addItemDecoration

open fun addItemDecoration(@NonNull decor: RecyclerView.ItemDecoration)

open fun addItemDecoration(@NonNull decor: RecyclerView.ItemDecoration, index: Int)

Add an ItemDecoration to this ViewPager2.

open fun beginFakeDrag(): Boolean

Start a fake drag of the pager.

canScrollHorizontally

open fun canScrollHorizontally(direction: Int): Boolean

canScrollVertically

open fun canScrollVertically(direction: Int): Boolean

open fun endFakeDrag(): Boolean

End a fake drag of the pager.

open fun fakeDragBy(@Px offsetPxFloat: Float): Boolean

Fake drag by an offset in pixels.

getAccessibilityClassName

@RequiresApi(value = 23)

open fun getAccessibilityClassName(): CharSequence

open fun getAdapter(): RecyclerView.Adapter

open fun getCurrentItem(): Int

Returns the currently selected page.

getItemDecorationAt

open fun getItemDecorationAt(index: Int): RecyclerView.ItemDecoration

Returns an ItemDecoration previously added to this ViewPager2.

getItemDecorationCount

open fun getItemDecorationCount(): Int

Returns the number of ItemDecoration currently added to this ViewPager2.

getOffscreenPageLimit

open fun getOffscreenPageLimit(): Int

Returns the number of pages that will be retained to either side of the current page in the view hierarchy in an idle state.

open fun getOrientation(): Int

open fun getScrollState(): Int

Returns the current scroll state of the ViewPager2.

invalidateItemDecorations

open fun invalidateItemDecorations()

Invalidates all ItemDecorations.

open fun isFakeDragging(): Boolean

Returns true if a fake drag is in progress.

isUserInputEnabled

open fun isUserInputEnabled(): Boolean

Returns if user initiated scrolling between pages is enabled.

onInitializeAccessibilityNodeInfo

open fun onInitializeAccessibilityNodeInfo(info: AccessibilityNodeInfo)

open fun onViewAdded(child: View)

performAccessibilityAction

open fun performAccessibilityAction(action: Int, @Nullable arguments: Bundle): Boolean

registerOnPageChangeCallback

open fun registerOnPageChangeCallback(@NonNull callback: ViewPager2.OnPageChangeCallback)

Add a callback that will be invoked whenever the page changes or is incrementally scrolled.

removeItemDecoration

open fun removeItemDecoration(@NonNull decor: RecyclerView.ItemDecoration)

Remove an ItemDecoration from this ViewPager2.

removeItemDecorationAt

open fun removeItemDecorationAt(index: Int)

Removes the ItemDecoration associated with the supplied index position.

requestTransform

open fun requestTransform()

Trigger a call to the registered PageTransformer's transformPage method.

seslSetSuggestionPaging

open fun seslSetSuggestionPaging(suggestionPagingEnabled: Boolean)

open fun setAdapter(@Nullable adapter: RecyclerView.Adapter)

Set a new adapter to provide page views on demand.

open fun setCurrentItem(item: Int)

open fun setCurrentItem(item: Int, smoothScroll: Boolean)

Set the currently selected page.

setLayoutDirection

open fun setLayoutDirection(layoutDirection: Int)

setOffscreenPageLimit

open fun setOffscreenPageLimit(limit: Int)

Set the number of pages that should be retained to either side of the currently visible page(s).

open fun setOrientation(orientation: Int)

Sets the orientation of the ViewPager2.

setPageTransformer

open fun setPageTransformer(@Nullable transformer: ViewPager2.PageTransformer)

Sets a PageTransformer that will be called for each attached page whenever the scroll position is changed.

setUserInputEnabled

open fun setUserInputEnabled(enabled: Boolean)

Enable or disable user initiated scrolling.

unregisterOnPageChangeCallback

open fun unregisterOnPageChangeCallback(@NonNull callback: ViewPager2.OnPageChangeCallback)

Remove a callback that was previously added via registerOnPageChangeCallback.