mva2.adapter.util

Interface PayloadProvider<M>

Type Parameters:

M - Refers to the model class

public interface PayloadProvider<M>

A Interface class used by DiffUtil while calculating the diff between two lists.

Method Summary

Modifier and Type	Method and Description
boolean	areContentsTheSame(M oldItem, M newItem) Called by the DataManager when it wants to check whether two items have the same data.
boolean	areItemsTheSame(M oldItem, M newItem) Called by the DiffUtil to decide whether two object represent the same Item.
java.lang.Object	getChangePayload(M oldItem, M newItem) Called by the DataManager when it wants to get the payload of changed elements.

Method Detail

areContentsTheSame

boolean areContentsTheSame(M oldItem,
                           M newItem)

Called by the DataManager when it wants to check whether two items have the same data. DataManager uses this information to detect if the contents of an item has changed.

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

Parameters:

oldItem - The item in the old list

newItem - The item in the new list which replaces the oldItem

Returns:

True if the contents of the items are the same or false if they are different, ie., you should return whether the items' visual representations are the same.

areItemsTheSame

boolean areItemsTheSame(M oldItem,
                        M newItem)

Called by the DiffUtil to decide whether two object represent the same Item.

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

Parameters:

oldItem - The item in the old list

newItem - The item in the new list which replaces the oldItem

Returns:

True if the two items represent the same object or false if they are different.

getChangePayload

java.lang.Object getChangePayload(M oldItem,
                                  M newItem)

Called by the DataManager when it wants to get the payload of changed elements.

For example, if you are using DiffUtil with RecyclerView, you can return the particular field that changed in the item and your ItemAnimator can use that information to run the correct animation.

Default implementation returns null.

Parameters:

oldItem - The item in the old list

newItem - The item in the new list

Returns:

A payload object that represents the change between the two items.