Android APIs
public static class

SortedList.BatchedCallback

extends Callback<T2>
java.lang.Object
   ↳ android.support.v7.util.SortedList.Callback<T2>
     ↳ android.support.v7.util.SortedList.BatchedCallback<T2>

Class Overview

A callback implementation that can batch notify events dispatched by the SortedList.

This class can be useful if you want to do multiple operations on a SortedList but don't want to dispatch each event one by one, which may result in a performance issue.

For example, if you are going to add multiple items to a SortedList, BatchedCallback call convert individual onInserted(index, 1) calls into one onInserted(index, N) if items are added into consecutive indices. This change can help RecyclerView resolve changes much more easily.

If consecutive changes in the SortedList are not suitable for batching, BatchingCallback dispatches them as soon as such case is detected. After your edits on the SortedList is complete, you must always call dispatchLastEvent() to flush all changes to the Callback.

Summary

Public Constructors
SortedList.BatchedCallback(Callback<T2> wrappedCallback)
Creates a new BatchedCallback that wraps the provided Callback.
Public Methods
boolean areContentsTheSame(T2 oldItem, T2 newItem)
Called by the SortedList when it wants to check whether two items have the same data or not.
boolean areItemsTheSame(T2 item1, T2 item2)
Called by the SortedList to decide whether two object represent the same Item or not.
int compare(T2 o1, T2 o2)
Similar to compare(Object, Object), should compare two and return how they should be ordered.
void dispatchLastEvent()
This method dispatches any pending event notifications to the wrapped Callback.
void onChanged(int position, int count)
Called by the SortedList when the item at the given position is updated.
void onInserted(int position, int count)
Called by the SortedList when an item is inserted at the given position.
void onMoved(int fromPosition, int toPosition)
Called by the SortedList when an item changes its position in the list.
void onRemoved(int position, int count)
Called by the SortedList when an item is removed from the given position.
[Expand]
Inherited Methods
From class android.support.v7.util.SortedList.Callback
From class java.lang.Object

Public Constructors

public SortedList.BatchedCallback (Callback<T2> wrappedCallback)

Creates a new BatchedCallback that wraps the provided Callback.

Parameters
wrappedCallback The Callback which should received the data change callbacks. Other method calls (e.g. compare(Object, Object) from the SortedList are directly forwarded to this Callback.

Public Methods

public boolean areContentsTheSame (T2 oldItem, T2 newItem)

Called by the SortedList when it wants to check whether two items have the same data or not. SortedList uses this information to decide whether it should call onChanged(int, int) or not.

SortedList uses this method to check equality instead of equals(Object) so that you can change its behavior depending on your UI.

For example, if you are using SortedList with a RecyclerView.Adapter, you should return whether the items' visual representations are the same or not.

Parameters
oldItem The previous representation of the object.
newItem The new object that replaces the previous one.
Returns
  • True if the contents of the items are the same or false if they are different.

public boolean areItemsTheSame (T2 item1, T2 item2)

Called by the SortedList to decide whether two object represent the same Item or not.

For example, if your items have unique ids, this method should check their equality.

Parameters
item1 The first item to check.
item2 The second item to check.
Returns
  • True if the two items represent the same object or false if they are different.

public int compare (T2 o1, T2 o2)

Similar to compare(Object, Object), should compare two and return how they should be ordered.

Parameters
o1 The first object to compare.
o2 The second object to compare.
Returns
  • a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

public void dispatchLastEvent ()

This method dispatches any pending event notifications to the wrapped Callback. You must always call this method after you are done with editing the SortedList.

public void onChanged (int position, int count)

Called by the SortedList when the item at the given position is updated.

Parameters
position The position of the item which has been updated.
count The number of items which has changed.

public void onInserted (int position, int count)

Called by the SortedList when an item is inserted at the given position.

Parameters
position The position of the new item.
count The number of items that have been added.

public void onMoved (int fromPosition, int toPosition)

Called by the SortedList when an item changes its position in the list.

Parameters
fromPosition The previous position of the item before the move.
toPosition The new position of the item.

public void onRemoved (int position, int count)

Called by the SortedList when an item is removed from the given position.

Parameters
position The position of the item which has been removed.
count The number of items which have been removed.