SelectionObserver

Kotlin |Java

abstract class SelectionObserver<K : Any!>

kotlin.Any
↳	androidx.recyclerview.selection.SelectionTracker.SelectionObserver

Observer class providing access to information about Selection state changes.

Summary

Public constructors
<init>() Observer class providing access to information about Selection state changes.

Public methods
open Unit	onItemStateChanged(@NonNull key: K, selected: Boolean) Called when the state of an item has been changed.
open Unit	onSelectionChanged() Called immediately after completion of any set of changes, excluding those resulting in calls to onSelectionRefresh() and onSelectionRestored().
open Unit	onSelectionRefresh() Called when the underlying data set has changed.
open Unit	onSelectionRestored() Called immediately after selection is restored.

Public constructors

<init>

SelectionObserver()

Observer class providing access to information about Selection state changes.

Public methods

onItemStateChanged

open fun onItemStateChanged(@NonNull key: K, selected: Boolean): Unit

Called when the state of an item has been changed.

onSelectionChanged

open fun onSelectionChanged(): Unit

Called immediately after completion of any set of changes, excluding those resulting in calls to onSelectionRefresh() and onSelectionRestored().

onSelectionRefresh

open fun onSelectionRefresh(): Unit

Called when the underlying data set has changed. After this method is called SelectionTracker will traverse the existing selection, calling onItemStateChanged(K, boolean) for each selected item, and deselecting any items that cannot be selected given the updated data-set (and after consulting SelectionPredicate).

onSelectionRestored

open fun onSelectionRestored(): Unit

Called immediately after selection is restored. onItemStateChanged(K, boolean) will *not* be called for individual items in the selection.