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DataObserver

abstract class DataObserver
kotlin.Any
   ↳ androidx.leanback.widget.ObjectAdapter.DataObserver

A DataObserver can be notified when an ObjectAdapter's underlying data changes. Separate methods provide notifications about different types of changes.

Summary

Public constructors

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

Public methods

open Unit

Called whenever the ObjectAdapter's data has changed in some manner outside of the set of changes covered by the other range-based change notification methods.

open Unit
onItemMoved(fromPosition: Int, toPosition: Int)

Called when an item is moved from one position to another position

open Unit
onItemRangeChanged(positionStart: Int, itemCount: Int)

Called when a range of items in the ObjectAdapter has changed.

open Unit
onItemRangeChanged(positionStart: Int, itemCount: Int, payload: Any!)

Called when a range of items in the ObjectAdapter has changed.

open Unit
onItemRangeInserted(positionStart: Int, itemCount: Int)

Called when a range of items is inserted into the ObjectAdapter.

open Unit
onItemRangeRemoved(positionStart: Int, itemCount: Int)

Called when a range of items is removed from the ObjectAdapter.

Public constructors

<init>

DataObserver()

A DataObserver can be notified when an ObjectAdapter's underlying data changes. Separate methods provide notifications about different types of changes.

Public methods

onChanged

open fun onChanged(): Unit

Called whenever the ObjectAdapter's data has changed in some manner outside of the set of changes covered by the other range-based change notification methods.

onItemMoved

open fun onItemMoved(fromPosition: Int, toPosition: Int): Unit

Called when an item is moved from one position to another position

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

onItemRangeChanged

open fun onItemRangeChanged(positionStart: Int, itemCount: Int): Unit

Called when a range of items in the ObjectAdapter has changed. The basic ordering and structure of the ObjectAdapter has not changed.

Parameters
positionStart Int: The position of the first item that changed.
itemCount Int: The number of items changed.

onItemRangeChanged

open fun onItemRangeChanged(positionStart: Int, itemCount: Int, payload: Any!): Unit

Called when a range of items in the ObjectAdapter has changed. The basic ordering and structure of the ObjectAdapter has not changed.

Parameters
positionStart Int: The position of the first item that changed.
itemCount Int: The number of items changed.
payload Int: Optional parameter, use null to identify a "full" update.

onItemRangeInserted

open fun onItemRangeInserted(positionStart: Int, itemCount: Int): Unit

Called when a range of items is inserted into the ObjectAdapter.

Parameters
positionStart Int: The position of the first inserted item.
itemCount Int: The number of items inserted.

onItemRangeRemoved

open fun onItemRangeRemoved(positionStart: Int, itemCount: Int): Unit

Called when a range of items is removed from the ObjectAdapter.

Parameters
positionStart Int: The position of the first removed item.
itemCount Int: The number of items removed.