Summary: Nested Classes | Constants | Ctors | Methods | Protected Methods | Inherited Methods

ObjectAdapter

Kotlin |Java

public abstract class ObjectAdapter
extends Object

java.lang.Object
↳	androidx.leanback.widget.ObjectAdapter

Known direct subclasses ArrayObjectAdapter, CursorObjectAdapter, SparseArrayObjectAdapter ArrayObjectAdapter An ObjectAdapter implemented with an ArrayList.  CursorObjectAdapter An ObjectAdapter implemented with a Cursor.  SparseArrayObjectAdapter An ObjectAdapter implemented with a SparseArray.

---

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 classes
class	ObjectAdapter.DataObserver A DataObserver can be notified when an ObjectAdapter's underlying data changes.

Constants
int	NO_ID Indicates that an id has not been set.

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

Public methods
abstract Object	get(int position) Returns the item for the given position.
long	getId(int position) Returns the id for the given position.
final Presenter	getPresenter(Object item) Returns the Presenter for the given item from the adapter.
final PresenterSelector	getPresenterSelector() Returns the presenter selector for this ObjectAdapter.
final 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.
final void	notifyItemRangeChanged(int positionStart, int itemCount, Object payload) Notifies UI that some items has changed.
final void	notifyItemRangeChanged(int positionStart, int itemCount) Notifies UI that some items has changed.
final void	registerObserver(ObjectAdapter.DataObserver observer) Registers a DataObserver for data change notifications.
final void	setHasStableIds(boolean hasStableIds) Sets whether the item ids are stable across changes to the underlying data.
final void	setPresenterSelector(PresenterSelector presenterSelector) Sets the presenter selector.
abstract int	size() Returns the number of items in the adapter.
final void	unregisterAllObservers() Unregisters all DataObservers for this ObjectAdapter.
final void	unregisterObserver(ObjectAdapter.DataObserver observer) Unregisters a DataObserver for data change notifications.

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

Inherited methods
From class java.lang.Object Object clone() boolean equals(Object arg0) void finalize() final Class<?> getClass() int hashCode() final void notify() final void notifyAll() String toString() final void wait(long arg0, int arg1) final void wait(long arg0) final void wait()

Constants

NO_ID

public static final int NO_ID

Indicates that an id has not been set.

Constant Value: -1 (0xffffffff)

Public constructors

ObjectAdapter

public ObjectAdapter (PresenterSelector presenterSelector)

Constructs an adapter with the given PresenterSelector.

Parameters
presenterSelector	PresenterSelector

ObjectAdapter

public ObjectAdapter (Presenter presenter)

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

Parameters
presenter	Presenter

ObjectAdapter

public ObjectAdapter ()

Constructs an adapter.

Public methods

get

public abstract Object get (int position)

Returns the item for the given position.

Parameters
position	int

Returns
Object

getId

public long getId (int position)

Returns the id for the given position.

Parameters
position	int

Returns
long

getPresenter

public final Presenter getPresenter (Object item)

Returns the Presenter for the given item from the adapter.

Parameters
item	Object

Returns
Presenter

getPresenterSelector

public final PresenterSelector getPresenterSelector ()

Returns the presenter selector for this ObjectAdapter.

Returns
PresenterSelector

hasStableIds

public final boolean hasStableIds ()

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(int) to correlate Objects across changes.

Returns
boolean

isImmediateNotifySupported

public boolean isImmediateNotifySupported ()

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

Returns
boolean

notifyItemRangeChanged

public final void notifyItemRangeChanged (int positionStart, 
                int itemCount, 
                Object payload)

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	Object: Optional parameter, use null to identify a "full" update.

notifyItemRangeChanged

public final void notifyItemRangeChanged (int positionStart, 
                int itemCount)

Notifies UI that some items has changed.

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

registerObserver

public final void registerObserver (ObjectAdapter.DataObserver observer)

Registers a DataObserver for data change notifications.

Parameters
observer	ObjectAdapter.DataObserver

setHasStableIds

public final void setHasStableIds (boolean hasStableIds)

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

Parameters
hasStableIds	boolean

setPresenterSelector

public final void setPresenterSelector (PresenterSelector presenterSelector)

Sets the presenter selector. May not be null.

Parameters
presenterSelector	PresenterSelector

size

public abstract int size ()

Returns the number of items in the adapter.

Returns
int

unregisterAllObservers

public final void unregisterAllObservers ()

Unregisters all DataObservers for this ObjectAdapter.

unregisterObserver

public final void unregisterObserver (ObjectAdapter.DataObserver observer)

Unregisters a DataObserver for data change notifications.

Parameters
observer	ObjectAdapter.DataObserver

Protected methods

notifyChanged

protected final void notifyChanged ()

Notifies UI that the underlying data has changed.

notifyItemMoved

protected final void notifyItemMoved (int fromPosition, 
                int toPosition)

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

protected final void notifyItemRangeInserted (int positionStart, 
                int itemCount)

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

protected final void notifyItemRangeRemoved (int positionStart, 
                int itemCount)

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

protected void onHasStableIdsChanged ()

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

onPresenterSelectorChanged

protected void onPresenterSelectorChanged ()

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