ObjectAdapter

Artifact: androidx.leanback:leanback

View Source

Added in 1.1.0

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Kotlin |Java

abstract class ObjectAdapter

Known direct subclasses

ArrayObjectAdapter, CursorObjectAdapter, PagingDataAdapter, SparseArrayObjectAdapter

ArrayObjectAdapter	An ObjectAdapter implemented with an ArrayList.
CursorObjectAdapter	An ObjectAdapter implemented with a Cursor.
PagingDataAdapter	An ObjectAdapter implemented with an AsyncPagingDataDiffer.
SparseArrayObjectAdapter	An ObjectAdapter implemented with a android.util.SparseArray.

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Base class adapter to be used in leanback activities. Provides access to a data model and is decoupled from the presentation of the items via PresenterSelector.

Summary

Nested types
abstract class ObjectAdapter.DataObserver A DataObserver can be notified when an ObjectAdapter's underlying data changes.

Constants
const Int	NO_ID = -1 Indicates that an id has not been set.

Public constructors
ObjectAdapter() Constructs an adapter.
ObjectAdapter(presenter: Presenter) Constructs an adapter that uses the given Presenter for all items.
ObjectAdapter(presenterSelector: PresenterSelector) Constructs an adapter with the given PresenterSelector.

Public functions
abstract Any?	get(position: Int) Returns the item for the given position.
Long	getId(position: Int) Returns the id for the given position.
Presenter?	getPresenter(item: Any) Returns the Presenter for the given item from the adapter.
PresenterSelector	getPresenterSelector() Returns the presenter selector for this ObjectAdapter.
Boolean	hasStableIds() Returns true if the item ids are stable across changes to the underlying data.
Boolean	isImmediateNotifySupported() Returns true if the adapter pairs each underlying data change with a call to notify and false otherwise.
Unit	notifyItemRangeChanged(positionStart: Int, itemCount: Int) Notifies UI that some items has changed.
Unit	notifyItemRangeChanged(positionStart: Int, itemCount: Int, payload: Any?) Notifies UI that some items has changed.
Unit	registerObserver(observer: ObjectAdapter.DataObserver) Registers a DataObserver for data change notifications.
Unit	setHasStableIds(hasStableIds: Boolean) Sets whether the item ids are stable across changes to the underlying data.
Unit	setPresenterSelector(presenterSelector: PresenterSelector) Sets the presenter selector.
abstract Int	size() Returns the number of items in the adapter.
Unit	unregisterAllObservers() Unregisters all DataObservers for this ObjectAdapter.
Unit	unregisterObserver(observer: ObjectAdapter.DataObserver) Unregisters a DataObserver for data change notifications.

Protected functions
Unit	notifyChanged() Notifies UI that the underlying data has changed.
Unit	notifyItemMoved(fromPosition: Int, toPosition: Int) Notifies UI that item at fromPosition has been moved to toPosition.
Unit	notifyItemRangeInserted(positionStart: Int, itemCount: Int) Notifies UI that new items has been inserted.
Unit	notifyItemRangeRemoved(positionStart: Int, itemCount: Int) Notifies UI that some items that has been removed.
Unit	onHasStableIdsChanged() Called when setHasStableIds is called and the status of stable ids has changed.
Unit	onPresenterSelectorChanged() Called when setPresenterSelector is called and the PresenterSelector differs from the previous one.

Constants

NO_ID

Added in 1.1.0

const val NO_ID = -1: Int

Indicates that an id has not been set.

Public constructors

ObjectAdapter

Added in 1.1.0

ObjectAdapter()

Constructs an adapter.

ObjectAdapter

Added in 1.1.0

ObjectAdapter(presenter: Presenter)

Constructs an adapter that uses the given Presenter for all items.

ObjectAdapter

Added in 1.1.0

ObjectAdapter(presenterSelector: PresenterSelector)

Constructs an adapter with the given PresenterSelector.

Public functions

get

Added in 1.1.0

abstract fun get(position: Int): Any?

Returns the item for the given position.

getId

Added in 1.1.0

fun getId(position: Int): Long

Returns the id for the given position.

getPresenter

Added in 1.1.0

fun getPresenter(item: Any): Presenter?

Returns the Presenter for the given item from the adapter.

getPresenterSelector

Added in 1.1.0

fun getPresenterSelector(): PresenterSelector

Returns the presenter selector for this ObjectAdapter.

hasStableIds

Added in 1.1.0

fun hasStableIds(): Boolean

Returns true if the item ids are stable across changes to the underlying data. When this is true, clients of the ObjectAdapter can use getId to correlate Objects across changes.

isImmediateNotifySupported

Added in 1.1.0

fun isImmediateNotifySupported(): Boolean

Returns true if the adapter pairs each underlying data change with a call to notify and false otherwise.

notifyItemRangeChanged

Added in 1.1.0

fun notifyItemRangeChanged(positionStart: Int, itemCount: Int): Unit

Notifies UI that some items has changed.

Parameters
positionStart: Int	Starting position of the changed items.
itemCount: Int	Total number of items that changed.

notifyItemRangeChanged

Added in 1.1.0

fun notifyItemRangeChanged(positionStart: Int, itemCount: Int, payload: Any?): Unit

Notifies UI that some items has changed.

Parameters
positionStart: Int	Starting position of the changed items.
itemCount: Int	Total number of items that changed.
payload: Any?	Optional parameter, use null to identify a "full" update.

registerObserver

Added in 1.1.0

fun registerObserver(observer: ObjectAdapter.DataObserver): Unit

Registers a DataObserver for data change notifications.

setHasStableIds

Added in 1.1.0

fun setHasStableIds(hasStableIds: Boolean): Unit

Sets whether the item ids are stable across changes to the underlying data.

setPresenterSelector

Added in 1.1.0

fun setPresenterSelector(presenterSelector: PresenterSelector): Unit

Sets the presenter selector. May not be null.

size

Added in 1.1.0

abstract fun size(): Int

Returns the number of items in the adapter.

unregisterAllObservers

Added in 1.1.0

fun unregisterAllObservers(): Unit

Unregisters all DataObservers for this ObjectAdapter.

unregisterObserver

Added in 1.1.0

fun unregisterObserver(observer: ObjectAdapter.DataObserver): Unit

Unregisters a DataObserver for data change notifications.

Protected functions

notifyChanged

Added in 1.1.0

protected fun notifyChanged(): Unit

Notifies UI that the underlying data has changed.

notifyItemMoved

Added in 1.1.0

protected fun notifyItemMoved(fromPosition: Int, toPosition: Int): Unit

Notifies UI that item at fromPosition has been moved to toPosition.

Parameters
fromPosition: Int	Previous position of the item.
toPosition: Int	New position of the item.

notifyItemRangeInserted

Added in 1.1.0

protected fun notifyItemRangeInserted(positionStart: Int, itemCount: Int): Unit

Notifies UI that new items has been inserted.

Parameters
positionStart: Int	Position where new items has been inserted.
itemCount: Int	Count of the new items has been inserted.

notifyItemRangeRemoved

Added in 1.1.0

protected fun notifyItemRangeRemoved(positionStart: Int, itemCount: Int): Unit

Notifies UI that some items that has been removed.

Parameters
positionStart: Int	Starting position of the removed items.
itemCount: Int	Total number of items that has been removed.

onHasStableIdsChanged

Added in 1.1.0

protected fun onHasStableIdsChanged(): Unit

Called when setHasStableIds is called and the status of stable ids has changed.

onPresenterSelectorChanged

Added in 1.1.0

protected fun onPresenterSelectorChanged(): Unit

Called when setPresenterSelector is called and the PresenterSelector differs from the previous one.