viewpager2/androidx.viewpager2.adapter/FragmentStateAdapter

FragmentStateAdapter

abstract class FragmentStateAdapter : RecyclerView.Adapter<VH> , StatefulAdapter(source)

Similar in behavior to FragmentStatePagerAdapter

Lifecycle within RecyclerView:

RecyclerView.ViewHolder initially an empty FrameLayout, serves as a re-usable container for a Fragment in later stages.
onBindViewHolder we ask for a Fragment for the position. If we already have the fragment, or have previously saved its state, we use those.
onAttachedToWindow we attach the Fragment to a container.
onViewRecycled we remove, save state, destroy the Fragment.

Constructors

FragmentStateAdapter

constructor(@NonNull fragmentActivity: FragmentActivity)

constructor(@NonNull fragment: Fragment)

constructor(@NonNull fragmentManager: FragmentManager, @NonNull lifecycle: Lifecycle)

Types

ExperimentalFragmentStateAdapterApi

annotation class ExperimentalFragmentStateAdapterApi

FragmentTransactionCallback

abstract class FragmentTransactionCallback

Callback interface for listening to fragment lifecycle changes that happen inside the adapter.

Functions

open fun containsItem(itemId: Long): Boolean

Default implementation works for collections that don't add, move, remove items.

abstract fun createFragment(position: Int): Fragment

Provide a new Fragment associated with the specified position.

open fun getItemId(position: Int): Long

Default implementation works for collections that don't add, move, remove items.

onAttachedToRecyclerView

open fun onAttachedToRecyclerView(@NonNull recyclerView: RecyclerView)

onBindViewHolder

fun onBindViewHolder(@NonNull holder: FragmentViewHolder, position: Int)

onCreateViewHolder

fun onCreateViewHolder(@NonNull parent: ViewGroup, viewType: Int): FragmentViewHolder

onDetachedFromRecyclerView

open fun onDetachedFromRecyclerView(@NonNull recyclerView: RecyclerView)

onFailedToRecycleView

fun onFailedToRecycleView(@NonNull holder: FragmentViewHolder): Boolean

onViewAttachedToWindow

fun onViewAttachedToWindow(@NonNull holder: FragmentViewHolder)

fun onViewRecycled(@NonNull holder: FragmentViewHolder)

registerFragmentTransactionCallback

open fun registerFragmentTransactionCallback(@NonNull callback: FragmentStateAdapter.FragmentTransactionCallback)

Registers a FragmentTransactionCallback to listen to fragment lifecycle changes that happen inside the adapter.

fun restoreState(@NonNull savedState: Parcelable)

Restores adapter state

fun saveState(): Parcelable

Saves adapter state

setHasStableIds

fun setHasStableIds(hasStableIds: Boolean)

unregisterFragmentTransactionCallback

open fun unregisterFragmentTransactionCallback(@NonNull callback: FragmentStateAdapter.FragmentTransactionCallback)

Unregisters a FragmentTransactionCallback.