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belongs to Maven artifact androidx.leanback:leanback:1.1.0-alpha01

ObjectAdapter

public abstract class ObjectAdapter
extends Object

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


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

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.